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Circulation: Arrhythmia and Electrophysiology On the Beat

Paul J. Wang, MD

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Circulation: Arrhythmia and Electrophysiology On the Beat
Circulation: Arrhythmia and Electrophysiology On the Beat

Circulation: Arrhythmia and Electrophysiology On the Beat

Paul J. Wang, MD

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Each podcast will include key highlights from the journal's current issue and a report on new research published in the field of arrhythmia and electrophysiology.

Latest Episodes

Circulation: Arrhythmia and Electrophysiology September 2019 Issue

Dr Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Ying Tian and associates examine the effects and long-term outcomes of percutaneous stellate ganglion blockade in the setting of drug refractory electrical storm due to ventricular arrhythmia. They studied 30 consecutive patients over nearly a five-year period. They used bupivacaine alone, or in combination with lidocaine injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion in 15 patients, or both stellate ganglion in 15 patients. The mean left ventricular ejection fraction was 34%. At 24 hours, 60% of patients were free of ventricular arrhythmia. Patients whose ventricular arrhythmia was controlled had a lower hospital mortality rate than patients whose ventricular arrhythmia continued. 5.6 versus 50%, P equals 0.009. Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in ventricular arrhythmia episodes from 26 to 2 in the 72 hours after stellate ganglion blockade, P less than 0.001. Patients who died during the same hospitalization, N equals 7, were more likely to have ischemic cardiomyopathy, 100% versus 43.5%. And recurrent ventricular arrhythmias within 24 hours, 85.7% versus 26.1%. There were no procedure related complications. In our next paper, Zachi Attia and associates hypothesized that a convolutional neural network could be trained through a process called 'deep learning' to predict a person's age and gender using only 12-lead electrocardiogram signals. They trained convolutional neural network using 10 second samples of 12-lead ECG signals from 499,727 patients to predict gender and age. The networks were tested on a separate cohort of 275,056 patients. For gender classification, the model obtained 90.4% classification accuracy with an area under the curve of 0.97. In the independent test data, age was estimated as a continuous variable with an average error of 6.9 years, R squared equals 0.7. Among 100 hundred patients with multiple ECGs over the course of at least two decades of life, most patients, 51%, had an average error between real age and convolutional neural network predicted age of less than seven years. Major factors seen amongst patients with convolutional neural network predicted age that exceeded chronologic age by greater than seven years included low ejection fraction, hypertension, and coronary disease, P less than 0.1. In the 27% of patients whose correlation was greater than 0.8, between convolutional neural network predicted and chronological age, no incident events occurred over follow up 30 years. The authors concluded that applying artificial intelligence to the ECG allows prediction of patient, gender, and estimation of age. The ability of artificial intelligent algorithm to determine physiological age with further validation may serve as a measure of overall health. In our next paper, Zain Ul Abideen Asad and associates performed a meta-analysis of randomized control trials in order to compare the efficacy and safety of catheter ablation with medical therapy for atrial fibrillation with the primary outcome being all-cause mortality. They examined 18 randomized controlled trials comprising 4,464 patients. Catheter ablation resulted in significant reduction in all-cause mortality, relative risk of 0.69 that was driven by patients with atrial fibrillation and heart failure in reduced ejection fraction, relative risk 0.52. Catheter ablation resulted in significantly fewer cardiovascular hospitalizations, hazard ratio of 0.56, and fewer recurrences of atrial arrhythmia, relative risk 0.42. Subgroup analysis suggested that younger patients, age less than 65 years, and men derived more benefit from catheter ablation compared to medical therapy. In our next paper, Felipe Kazmirczak, Ko-Hsu

14 MINSEP 19
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Circulation: Arrhythmia and Electrophysiology September 2019 Issue

Circulation: Arrhythmia and Electrophysiology August 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Mark McCauley, Flavia Vitale and associates report that carbon nanotube fibers may improve impaired myocardial conduction. In three sheep, radiofrequency ablation was used to create epicardial conduction delay. In addition, in a rodent model, carbon nanotube fibers were sewn across the atrial ventricular junction. They demonstrated acute ventricular preexcitation, but in chronic studies at four weeks, atrial pacing was required for resumption of AV conduction. Carbon nanotube fibers are conductive, biocompatible with no gross or histopathological evidence of toxicity. In our next paper, Koichiro Ejima and associates compared outcomes of circumferential pulmonary vein isolation for atrial fibrillation ablation randomized to contact force monitoring or unipolar signal modification in 136 patients with paroxysmal atrial fibrillation. In the unipolar signal modification-guided group, each radiofrequency application was delivered until the development of completely positive unipolar electrograms. In the contact force monitoring-guided group, a contact force of 20 grams, ranged 10 to 30 grams, and a minimum force time integral of 400 gram seconds were the targets for each radiofrequency application. The freedom from atrial tachyarrhythmia recurrence at 12 months was 85% in the unipolar signal modification-guided group and 70% in the contact force monitoring-guided group, P equals 0.031. The radiofrequency time for pulmonary vein isolation was shorter in the unipolar signal modification-guided group than contact force monitoring-guided group, but was not statistically significant, P equals 0.077. The incidence of time-dependent in ATP-provoked early electrical reconnections between the left atrium and pulmonary veins, procedural time, fluoroscopic time, and average force-time integral did not significantly differ between the two groups. In our next paper, Vishal Luther and associates tested whether ripple mapping is superior to conventional annotation-based local activation time mapping for atrial tachycardia diagnosis. Patients with atrial tachycardia were randomized, either ripple mapping or local activation time mapping. The primary endpoint was atrial tachycardia termination with delivery of the planned ablation lesion set. The inability to terminate atrial tachycardia with the first lesion set, the use of more than one entrainment maneuver, or the need to cross over to the other mapping arm were defined as failure to achieve the primary endpoint. The primary endpoint occurred in 38 of 42 patients or 90% in the ripple mapping group, and 29 of 41 patients, 71%, in the local activation time mapping group, P equals 0.45. The primary endpoint was achieved without any entrainment in 31 out of 42 patients or 74% with ripple mapping, and 18 out of 41 patients or 44% with local activation time mapping, P equals 0.01. Of those patients who failed to achieve the primary endpoint, atrial tachycardia termination was achieved in 9 out of 12 patients or 75% in the local activation time mapping group following crossover to ripple mapping with entrainment, but zero out of four patients, 0%, in ripple mapping group crossing over to local activation time mapping with entrainment, P equals 0.04. In our next paper, Franziska Fochler and associates examined whether anatomical targeting of late gadolinium enhancement MRI-detected gaps and superficial atrial scar is feasible and effective to treat recurrent atrial arrhythmias post-atrial fibrillation ablation. The authors studied 102 patients who underwent initial atrial fibrillation ablation and repeat ablation for recurrent atrial arrhythmias within one-year. 46 patients or 45% with atrial fibrillation recurrence were assigned to group one and underwent fibrosis homogeniza

13 MINAUG 27
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Circulation: Arrhythmia and Electrophysiology August 2019 Issue

Circulation: Arrhythmia and Electrophysiology July 2018 Issue

Paul Wang: Welcome to the monthly podcast On The Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, editor in chief, with some of the key highlights from this month's issue. In our first paper, Moo-Nyun Jin, Tae-Hoon Kim, and associates examined the 1-year serial changes in cognitive function, with or without atrial fibrillation catheter ablation. They used the Montreal cognitive assessment score in 308 patients undergoing atrial fibrillation ablation, the ablation group and 50 atrial fibrillation patients on medical therapy who met the same indication for atrial fibrillation ablation, the control group at baseline three months and 12 months. Cognitive impairment was defined as a published cutoff score of less than 23 points. Pre-ablation cognitive impairment was a detected in 18.5%. The Montreal cognitive assessment score significantly improved one year after radio frequency ablation. In both the overall ablation group, 24.9 to 26.4 p less than 0.001, and the propensity matched ablation group 25.4 to 26.5, but not in the control group. 25.4 to 24.8 p equals 0.012. Pre-ablation cognitive pyramid odds ratio 13.7, was independently associated with an improvement in one-year post ablation cognitive function. In our next paper, Zian Tseng, James Salazar and associates studied World Health Organization defined sudden cardiac deaths autopsied in the POstmortem Systemic InvesTigation of sudden cardiac death, the POST SCD study to determine whether premortem characteristics could identify autopsy defined sudden arrhythmic death among presumed sudden cardiac deaths. They prospectively identified 615 World Health Organization defined sudden cardiac deaths, of which 144 were witnessed. Autopsy defined sudden arrhythmic death had no extra cardiac or acute heart failure cause of death. Of the 615 presumed sudden critic deaths, 348 or 57% were autopsy defined, sudden arrhythmic deaths. For witness cases, using an emergency medical system model area under the receiver operator curve 0.75, included presenting rhythm of ventricular tech or cardiac fibrillation, pulseless electrical activity, while the comprehensive model, adding medical record data and depression, area under the curve 0.78. If only VTVF witness cases, 48 of those were classified as sudden arrhythmic death. The sensitivity was 0.46, and specificity 0.90. For unwitnessed cases, the emergency medical system model, area under the curve 0.68, included black race, male sex, age, time since last seen normal, while the comprehensive, area into the curve 0.75, added the use of beta blockers, antidepressants, QT prolonging drugs, opiates, illicit drugs and dyslipidemia. If only unwitnessed cases, less than one hour, n equals 59, were classified as sudden arrhythmic deaths, the sensitivities were 0.18, and specificity was 0.95. The authors concluded that models could identify pre-mortem characteristics to better specify autopsy defined sudden arrhythmic deaths, among presumed sudden cardiac arrests. The authors suggest that the World Health Organization definition can be improved by restricting witnessed sudden cardiac deaths to ventricular tachycardia fibrillation or non-pulseless electrical activity rhythms in unwitnessed cases to less than one hour since last normal, at a cost of sensitivity. In our next paper, Rafael Jaimes III and associates performed optical mapping of trends, membrane, voltage and pacing studies on isolated Langendorff-perfused rat hearts to assess the cardiac electrophysiology after mono-2-ethylhexyl phthalate, a phthalate with documented exposure in intensive care patients. The authors found that a 30-minute exposure to mono-2-ethylhexyl phthalate increased the atrioventricular node effector in period 147 milliseconds compared to 170 milliseconds in controls and increased the ventricular effective refractory periods of 117 milliseconds compared to 77.5 milliseconds in controls. Optical mapping revealed prolonged action potentia

15 MINJUL 16
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Circulation: Arrhythmia and Electrophysiology July 2018 Issue

Circulation: Arrhythmia and Electrophysiology June 2019 Issue

Dr. Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wong, editor-in-chief, with some of the key highlights from this month's issue. In our first paper, Jeremy Wasserlauf and associates compare the accuracy of an atrial fibrillation sensing smartwatch with simultaneous recordings from an insertable cardiac monitor. The authors use smart rhythm 2.0, a convolutional neuro-network, trained on anonymized data of heart rate, activity level and EKGs from 7500 AliveCor users. The network was validated on data collected in 24 patients with insertable cardiac monitor, and a history of paroxysmal atrial fibrillation who simultaneously wore the atrial fibrillation sensing smart watch with smart rhythm 0.1 software. The primary outcome was sensitivity of the atrial fibrillation sensing smart watch for atrial fibrillation episodes of greater than equal to one hour. Secondary end points include sensitivity of atrial fibrillation sensing smart watch for detection of atrial fibrillation by subject and sensitivity for total duration across all subjects. Subjects with greater than 50% false positive atrial fibrillation episodes on insertable cardiac monitor were excluded. The authors analyzed 31,349 hours meaning 11.3 hours per day of simultaneous atrial fibrillation sensing smart watch and insertable cardiac monitor recordings in 24 patients. Insertable cardiac monitor detected 82 episodes of atrial fibrillation of one hour duration or greater while the atrial fibrillation sensing smartwatch was worn. With a total duration of 1,127 hours. Of these, the smart rhythm 2.0 neural network detected 80 episodes. Episode sensitivity 97.5% with total duration 1,101 hours. Duration sensitivity 97.7%. Three of the 18 subjects with atrial fibrillation of one hour or greater had atrial fibrillation only when the watch was not being worn. Patient sensitivity 83.3% or 100% during the time worn. Positive predictive value for atrial fibrillation episodes was 39.9%. The authors concluded that an atrial fibrillation sensing smartwatch is highly sensitive to detection of atrial fibrillation and assessment of atrial fibrillation duration in an ambulatory population when compared to insertable cardiac monitor. In our next paper, Liliana Tavares and associates examine the autonomic nervous system response to apnea in its mechanistic connection to atrial fibrillation. They study the effects of ablation of cardiac sensory neurons with resiniferatoxin, a neurotoxic transient receptor potential vanilloid one agonist. In a canine model, apnea was induced by stopping ventilation until oxygen saturation decreased in 90%. Nerve recordings from bilateral vagal nerves left stellate ganglion and anterior right ganglion plexi were obtained before and during apnea, before and after resiniferatoxin injection in the anterior white ganglion plexi in seven animals. Each refractory period and atrial fibrillation inducibility upon single extra stimulation was assessed before and during apnea, before and after intrapericardial resiniferatoxin administration in nine animals. The authors found that apnea increased anterior wide ganglion plexi activity followed by cluster crescendo vagal bursts synchronized with heart rate and blood pressure oscillation. Upon further oxygen desaturation, a tonic increase in left stellate ganglion activity in blood pressure oscillations ensued. Apnea induced atrial effective refractory shortening from 110 to 90 milliseconds, P less than 0.001 and atrial fibrillation induction in nine animals vs. zero out of nine at baseline. After resiniferatoxin administration increases in ganglion plexi and left stellate ganglion activity, and blood pressure during apnea were abolished, in addition, the atrial effector refractory period increased to 127 milliseconds, P=0.0001 and atrial fibrillation was not induced. Vagal bursts remain unchanged. Ganglion plexi cells showed cytoplasmic microvacuo

17 MINJUN 19
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Circulation: Arrhythmia and Electrophysiology June 2019 Issue

Circulation: Arrhythmia and Electrophysiology May 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, editor-in-chief, with some of the key highlights from this month's issue. In our first article, Daniel Alyesh, Konstantinos Siontis and associates described myocardial calcifications in patients with ischemic cardiomyopathy undergoing ventricular tachycardia ablation in comparison to a control group of patients without ventricular tachycardia. They found that in 56 consecutive post-infarction patients, myocardial calcifications were identified in 39 or 70% of post-infarction ventricular tachycardia patients compared to 6 or 11% of patients without ventricular tachycardia. A calcification volume of 0.538 centimeters cube distinguished patients with calcification-associated ventricular tachycardia from patients without calcification-associated ventricular tachycardias; area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88. A non-confluent calcification pattern was associated with ventricular tachycardia target sites independent of calcification volume, P equals 0.01. Myocardial calcifications corresponding to areas of electrical non-excitability forming a border for re-entry were found in 33% of all ventricular tachycardias for which target sites were identified, and in 62% of patients with myocardial calcifications. In our next paper, Mia Fangel and associates examined whether glycemic status evaluated by hemoglobin A1c has an effect on the risk of thromboembolism among patients with atrial fibrillation and Type 2 diabetes. They used a cohort study from 5,386 patients with incident non-valvular atrial fibrillation and Type 2 diabetes in Danish registries. Compared with patients with hemoglobin A1c of less than or equal to 48 millimole per mole, they observed a higher risk of thromboembolism among patients with hemoglobin A1c 49 to 58 millimoles per mole with a hazard ratio of 1.49 and a hemoglobin A1c greater than 58 millimole per mole with a hazard ratio of 1.59 after adjusting for confounding factors. Surprisingly, in patients with diabetes duration of 10 years or more, higher hemoglobin A1c levels were not associated with a higher risk of thromboembolism. In our next paper, Niek Beurskens and associates compared tricuspid valve dysfunction in leadless pacemaker therapy to dual chamber transvenous pacing systems. They studied 53 patients receiving a leadless pacemaker, including 28 with a Nanostim and 25 with a Micra device. Of these 53 patients, 23 or 43% had tricuspid regurgitation that was graded as being more severe at 12 months. Compared with an apical position, a right ventricular septal position of the leadless pacemaker was associated with increased tricuspid valve incompetence, odds ratio, 5.20; P equals 0.03. An increase in mitral valve regurgitation was observed in 38% of patients. Leadless pacemaker implantation resulted in a reduction of right ventricular function. Leadless pacemaker implantation was further associated with a reduction in left ventricular ejection fraction and elevated LV TI index. The changes in tricuspid regurgitation in leadless pacing group was similar to the changes in dual-chamber transvenous pacemaker group, 43% versus 38% respectively; P equals 0.39. In our next paper, Jurgen Duchenne and associates examined whether regional left ventricular glucose metabolism correlates with regional work in an animal model with reversible dyssynchrony due to pacing. In 12 sheep, after 8 weeks of right atrial and right ventricular free wall pacing, there is evidence of left ventricular dilatation and thinning of the septum and thickening of the lateral wall. The authors employed motion compensation and anatomical correction in order to provide reliable regional estimates of myocardial glucose metabolism. They found that in homogenous regional distribution of myocardial workload due to left bundle branch block triggers adaptive remodeling of the left ventricl

11 MINMAY 22
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Circulation: Arrhythmia and Electrophysiology May 2019 Issue

Circulation: Arrhythmia and Electrophysiology April 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor in Chief, with some of the key highlights from this month's issue. In our first paper Lucas Boersma and associates examined the final two-year outcome data from 47 centers, in 1,020 patients receiving the left atrial appendage occlusion watchman devices. Their study population had a mean age of 73.4 years, with 311 having prior ischemic stroke or TIA, 153 having prior hemorrhagic stroke, and 318 having prior major bleeding. 49% had a CHAS II vast score of 5 or greater, and 40% had a HAS-BLED score of three or greater. Oral anticoagulation was contraindicated in 72%. During follow up, 161 patients, or 16.4% died, 22 strokes were observed or 1.3 per 100 patient years representing an 83% reduction versus historic data. And 47 major non-procedural bleeding events were observed, or 2.7 per 100 patient years representing a 46% reduction versus historic data. Device thrombus was observed in 34 patients or 4.1%, and was not correlated to the drug regimen during follow up. P=0.28. In our next paper, Anish Amin and Associates examined whether high voltage impedance and subcutaneous or SICD system implant position are associated with ventricular fibrillation or VF conversion success with a sub-maximal joule shock. In the SICD investigational device exemption study, a successful conversion test required two consecutive VF conversions at 65 joules in either shock vector. Sub-optimal device position was defined as an inferior electrode or pulse generator, or electrode coil depth of greater than three mm anterior to the sternum, based on chest radiograph. Of 314 patients who underwent SICD implantation, 282 patients were included in this analysis. There were 637 inductions to test defibrillation at 65 joules. 62 conversion failures, or 9.7%, occurred in 42 or 14.9% of patients. Lower body mass index or BMI, and lower shock impedance, were associated with higher conversion success rate. Whereas white race was associated with lower conversion success rate. Sub-optimal position was more common in obese patients. Inferior electrode and greater distance between the lead and sternum were associated with a higher impedance. When appropriate system position was achieved, conversion failure was not associated with high BMI. In our next paper, Je-Wook Park and associates examined the left atrial pressure after repeat radiofrequency catheter ablation procedures. Among 1,848 patients who underwent atrial fibrillation or AF catheter ablation, the authors measured the left atrial pressure, LAP, immediately following the transseptal puncture in sinus rhythm in 1,687 patients before De novo ablation, median age 59 years, 72.4% male and 72.8% paroxysmal AF, and in 142 with second procedures. In the same 142 patients, the degree of left atrial stiffness, reflected by LAPP, the difference between LAP peak and LAP nater, was significantly higher in the second procedure than in the De novo procedure. P<0.001. The degree of LAPP increase, delta LAPP, was significantly higher in patients who underwent additional extra pulmonary vein left atrial ablation than in those who underwent circumferential PV isolation alone. P=0.01. Extra pulmonary vein left atrial ablation was independently associated with delta LAPP. P=0.045. An increase LAPP during repeat procedures was independently associated with a reduced diastolic function. P=0.041. However, the EQ5D symptom score did not change after de novo ablation. In our next paper, Adam Graham and associates examined a median of 711 electrocardiographic imaging, or ECGI, in cardiopirin points per patient to compare simultaneous epicardial mapping using CARTO and ECGI after geometrical co registration in 8 patients. They found that the correlation coefficient measuring the similarity of activation times we equal to 0.66, and the correlation coefficient for repolarization times was 0.55.

11 MINAPR 17
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Circulation: Arrhythmia and Electrophysiology April 2019 Issue

Circulation: Arrhythmia and Electrophysiology March 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast "On the Beat" for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, Editor-in Chief, with some of the key highlights from this month's issue. In our first manuscript, Marie Bayer Elming and associates, examined whether the right ventricular ejection fraction can identify patients with non-ischemic systolic heart failure, more likely to benefit from ICD implantation. The Danish study, to assess the efficacy of ICDs in patients with non-ischemic systolic heart failure, on mortality, the Danish study, randomized patients with non-ischemic systolic heart failure to ICD our control. In 239 patients with interpretable cardiovascular magnetic resonance images, the right ventricular volume and ejection fraction was measured. Right ventricular ejection fraction was an independent predictor of all-cause mortality, with a hazard ration 1.34 per 10% absolute decrease in our right ventricular ejection fraction. P=0.02. There is statistically significant interaction between right ventricular ejection fraction and the effect of ICD implantation. P=0.001. ICD implantation significantly reduced all-cause mortality in patients with right ventricular systolic dysfunction. Hazard ratio 0.41, but not in patients without right ventricular systolic dysfunction. Thus, in this post-hoc analysis of the Danish trial, ICD therapy was associated with survival benefit in patients with bi-ventricular heart failure. In our next paper, Dawn Pedrotty and Volodymyr Kuzmenko and associates, have proposed a concept of using a stretchable, flexible, bio patch, with conductive properties, to attempt to restore conduction across regions in which activation is disrupted. They use carbon nanotube patches, composed of nanofibrillated cellulose, in single wall carbon nanotube ink, 3-D printed in conductive patterns onto bacterial nanocellulose. Electro anatomic mapping was performed on normal epicardium and repeated over surgically disruptive epicardium, and finally with the patch applied passively. The patch resulted in restored conduction based on mapping. In our next paper, Ayman Hussein and colleagues developed a fully automated platform to collect patient reported outcomes in a prospective cohort of atrial fibrillation ablation. Two thousand one hundred and seventy-five patients were eligible to receive 10,903 patient reported outcome assessment invitations. More follow up assessments were obtained with automated patient reported outcomes in routine follow-up, compared with routine follow up alone, P > 0.001, which allowed for longer duration of follow up, 378 vs 217 days. By automated patient reported outcomes, a large number of disease specific variables were collected and showed improvement in quality of life. Baseline median AF symptom severity score of 12 and ranged between 2 and 3 on subsequent assessments, P > 0.0001. This improvement was also true for each of the atrial fibrillation symptom severity score components. In patient reported outcomes, there was a significant reduction in atrial fibrillation burden, such as frequency and duration episodes and associated healthcare utilization including emergency visits and hospitalizations after the ablation procedures. In our next paper, Nicolas Johner, Dipen Shah, and associates, examined the role of post pacing intervals shorter than tachycardia cycling during entrainment mapping. The author studied 24 non-cavotricuspid isthmus dependent macro oriented atrial flutters in 19 consecutive patients. High density electro anatomic activation maps were acquired with a 64-electrode basket catheter of 102 entrainment mapping sites. Post pacing interval difference less than 30 was observed at 72 sites on complete maps of 24 atypical atrial flutters compared to sites with the difference in post pacing intervals 0 to 30, with 45 sites difference in the post pacing interval less than 0 at 27 were more commonly located within isthmuses less than 15mm wid

15 MINMAR 25
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Circulation: Arrhythmia and Electrophysiology March 2019 Issue

Circulation: Arrhythmia and Electrophysiology February 2019 Issue

Dr Paul Wong: Welcome to the monthly podcast on the beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wong, Editor-in Chief with some of the key highlights from this month's issue. This month's issue is dedicated to a new exciting topic, His bundle pacing. His bundle pacing is designed to achieve a more physiological human dynamic response than right ventricular pacing alone, which may be needed in patients with AV conduction abnormalities. In our first paper, Marek Jastrzebski and associates examined whether program stimulation may be used to distinguish nonselective His bundle capture from right ventricular myocardial capture. Premature beats were introduced at 10 millisecond steps during intrinsic rhythm, and also after a drive train of 600 milli seconds. The longest coupling interval that resulted in an abrupt change in the QRS morphology was considered equal to the effective refractory period of the His bundle or right ventricular myocardium. Program His bundl...

9 MINFEB 20
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Circulation: Arrhythmia and Electrophysiology February 2019 Issue

Circulation: Arrhythmia and Electrophysiology january 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. Koji Miyamoto and associates conducted the AD-Balloon Study, which investigates the ideal number of free cycles during second-generation cryoballoon pulmonary vein isolation. In a prospective, multicenter, randomized clinical trial, the authors compared in 110 patients the addition of a three minute freeze after pulmonary vein isolation had been achieved to pulmonary vein isolation alone. Delayed-enhancement magnetic resonance imaging was also performed one to two months after the pulmonary vein isolation to assess the ablation lesions. The freedom from atrial arrhythmias at one year was similar. Log rank test, P equals 0.78 in the two groups, 87.3% in the extra three-minute freeze group, and 89.1% in the pulmonary vein isolation group. There was no significant difference in the freq...

11 MINJAN 16
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Circulation: Arrhythmia and Electrophysiology january 2019 Issue

Circulation: Arrhythmia and Electrophysiology December 2018 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, editor in chief, with some of the key highlights for this month's issue. In our first paper, Pasquale Vergara and Associates develop a predictive risk score to assess the outcome of ventricular tachycardia ablation creating what they call the IVT score. The authors examined 16 demographics, clinical, and procedural related variables in 1,251 patients. They used a technique called survival tree analysis, which uses a recursive partitioning algorithm to find relationships among variables. They then compared the survival time and time to VT recurrence in groups derived from survival tree analysis using a log rank test. A random forest analysis was then run to extract a variable importance index and internally validate the survival tree models. They found that the left ventricular ejection fraction, ICD, or CRT device, previous ablation were the best predictors...

14 MIN2018 DEC 19
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Circulation: Arrhythmia and Electrophysiology December 2018 Issue

Latest Episodes

Circulation: Arrhythmia and Electrophysiology September 2019 Issue

Dr Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Ying Tian and associates examine the effects and long-term outcomes of percutaneous stellate ganglion blockade in the setting of drug refractory electrical storm due to ventricular arrhythmia. They studied 30 consecutive patients over nearly a five-year period. They used bupivacaine alone, or in combination with lidocaine injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion in 15 patients, or both stellate ganglion in 15 patients. The mean left ventricular ejection fraction was 34%. At 24 hours, 60% of patients were free of ventricular arrhythmia. Patients whose ventricular arrhythmia was controlled had a lower hospital mortality rate than patients whose ventricular arrhythmia continued. 5.6 versus 50%, P equals 0.009. Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in ventricular arrhythmia episodes from 26 to 2 in the 72 hours after stellate ganglion blockade, P less than 0.001. Patients who died during the same hospitalization, N equals 7, were more likely to have ischemic cardiomyopathy, 100% versus 43.5%. And recurrent ventricular arrhythmias within 24 hours, 85.7% versus 26.1%. There were no procedure related complications. In our next paper, Zachi Attia and associates hypothesized that a convolutional neural network could be trained through a process called 'deep learning' to predict a person's age and gender using only 12-lead electrocardiogram signals. They trained convolutional neural network using 10 second samples of 12-lead ECG signals from 499,727 patients to predict gender and age. The networks were tested on a separate cohort of 275,056 patients. For gender classification, the model obtained 90.4% classification accuracy with an area under the curve of 0.97. In the independent test data, age was estimated as a continuous variable with an average error of 6.9 years, R squared equals 0.7. Among 100 hundred patients with multiple ECGs over the course of at least two decades of life, most patients, 51%, had an average error between real age and convolutional neural network predicted age of less than seven years. Major factors seen amongst patients with convolutional neural network predicted age that exceeded chronologic age by greater than seven years included low ejection fraction, hypertension, and coronary disease, P less than 0.1. In the 27% of patients whose correlation was greater than 0.8, between convolutional neural network predicted and chronological age, no incident events occurred over follow up 30 years. The authors concluded that applying artificial intelligence to the ECG allows prediction of patient, gender, and estimation of age. The ability of artificial intelligent algorithm to determine physiological age with further validation may serve as a measure of overall health. In our next paper, Zain Ul Abideen Asad and associates performed a meta-analysis of randomized control trials in order to compare the efficacy and safety of catheter ablation with medical therapy for atrial fibrillation with the primary outcome being all-cause mortality. They examined 18 randomized controlled trials comprising 4,464 patients. Catheter ablation resulted in significant reduction in all-cause mortality, relative risk of 0.69 that was driven by patients with atrial fibrillation and heart failure in reduced ejection fraction, relative risk 0.52. Catheter ablation resulted in significantly fewer cardiovascular hospitalizations, hazard ratio of 0.56, and fewer recurrences of atrial arrhythmia, relative risk 0.42. Subgroup analysis suggested that younger patients, age less than 65 years, and men derived more benefit from catheter ablation compared to medical therapy. In our next paper, Felipe Kazmirczak, Ko-Hsu

14 MINSEP 19
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Circulation: Arrhythmia and Electrophysiology September 2019 Issue

Circulation: Arrhythmia and Electrophysiology August 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. In our first paper, Mark McCauley, Flavia Vitale and associates report that carbon nanotube fibers may improve impaired myocardial conduction. In three sheep, radiofrequency ablation was used to create epicardial conduction delay. In addition, in a rodent model, carbon nanotube fibers were sewn across the atrial ventricular junction. They demonstrated acute ventricular preexcitation, but in chronic studies at four weeks, atrial pacing was required for resumption of AV conduction. Carbon nanotube fibers are conductive, biocompatible with no gross or histopathological evidence of toxicity. In our next paper, Koichiro Ejima and associates compared outcomes of circumferential pulmonary vein isolation for atrial fibrillation ablation randomized to contact force monitoring or unipolar signal modification in 136 patients with paroxysmal atrial fibrillation. In the unipolar signal modification-guided group, each radiofrequency application was delivered until the development of completely positive unipolar electrograms. In the contact force monitoring-guided group, a contact force of 20 grams, ranged 10 to 30 grams, and a minimum force time integral of 400 gram seconds were the targets for each radiofrequency application. The freedom from atrial tachyarrhythmia recurrence at 12 months was 85% in the unipolar signal modification-guided group and 70% in the contact force monitoring-guided group, P equals 0.031. The radiofrequency time for pulmonary vein isolation was shorter in the unipolar signal modification-guided group than contact force monitoring-guided group, but was not statistically significant, P equals 0.077. The incidence of time-dependent in ATP-provoked early electrical reconnections between the left atrium and pulmonary veins, procedural time, fluoroscopic time, and average force-time integral did not significantly differ between the two groups. In our next paper, Vishal Luther and associates tested whether ripple mapping is superior to conventional annotation-based local activation time mapping for atrial tachycardia diagnosis. Patients with atrial tachycardia were randomized, either ripple mapping or local activation time mapping. The primary endpoint was atrial tachycardia termination with delivery of the planned ablation lesion set. The inability to terminate atrial tachycardia with the first lesion set, the use of more than one entrainment maneuver, or the need to cross over to the other mapping arm were defined as failure to achieve the primary endpoint. The primary endpoint occurred in 38 of 42 patients or 90% in the ripple mapping group, and 29 of 41 patients, 71%, in the local activation time mapping group, P equals 0.45. The primary endpoint was achieved without any entrainment in 31 out of 42 patients or 74% with ripple mapping, and 18 out of 41 patients or 44% with local activation time mapping, P equals 0.01. Of those patients who failed to achieve the primary endpoint, atrial tachycardia termination was achieved in 9 out of 12 patients or 75% in the local activation time mapping group following crossover to ripple mapping with entrainment, but zero out of four patients, 0%, in ripple mapping group crossing over to local activation time mapping with entrainment, P equals 0.04. In our next paper, Franziska Fochler and associates examined whether anatomical targeting of late gadolinium enhancement MRI-detected gaps and superficial atrial scar is feasible and effective to treat recurrent atrial arrhythmias post-atrial fibrillation ablation. The authors studied 102 patients who underwent initial atrial fibrillation ablation and repeat ablation for recurrent atrial arrhythmias within one-year. 46 patients or 45% with atrial fibrillation recurrence were assigned to group one and underwent fibrosis homogeniza

13 MINAUG 27
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Circulation: Arrhythmia and Electrophysiology August 2019 Issue

Circulation: Arrhythmia and Electrophysiology July 2018 Issue

Paul Wang: Welcome to the monthly podcast On The Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wang, editor in chief, with some of the key highlights from this month's issue. In our first paper, Moo-Nyun Jin, Tae-Hoon Kim, and associates examined the 1-year serial changes in cognitive function, with or without atrial fibrillation catheter ablation. They used the Montreal cognitive assessment score in 308 patients undergoing atrial fibrillation ablation, the ablation group and 50 atrial fibrillation patients on medical therapy who met the same indication for atrial fibrillation ablation, the control group at baseline three months and 12 months. Cognitive impairment was defined as a published cutoff score of less than 23 points. Pre-ablation cognitive impairment was a detected in 18.5%. The Montreal cognitive assessment score significantly improved one year after radio frequency ablation. In both the overall ablation group, 24.9 to 26.4 p less than 0.001, and the propensity matched ablation group 25.4 to 26.5, but not in the control group. 25.4 to 24.8 p equals 0.012. Pre-ablation cognitive pyramid odds ratio 13.7, was independently associated with an improvement in one-year post ablation cognitive function. In our next paper, Zian Tseng, James Salazar and associates studied World Health Organization defined sudden cardiac deaths autopsied in the POstmortem Systemic InvesTigation of sudden cardiac death, the POST SCD study to determine whether premortem characteristics could identify autopsy defined sudden arrhythmic death among presumed sudden cardiac deaths. They prospectively identified 615 World Health Organization defined sudden cardiac deaths, of which 144 were witnessed. Autopsy defined sudden arrhythmic death had no extra cardiac or acute heart failure cause of death. Of the 615 presumed sudden critic deaths, 348 or 57% were autopsy defined, sudden arrhythmic deaths. For witness cases, using an emergency medical system model area under the receiver operator curve 0.75, included presenting rhythm of ventricular tech or cardiac fibrillation, pulseless electrical activity, while the comprehensive model, adding medical record data and depression, area under the curve 0.78. If only VTVF witness cases, 48 of those were classified as sudden arrhythmic death. The sensitivity was 0.46, and specificity 0.90. For unwitnessed cases, the emergency medical system model, area under the curve 0.68, included black race, male sex, age, time since last seen normal, while the comprehensive, area into the curve 0.75, added the use of beta blockers, antidepressants, QT prolonging drugs, opiates, illicit drugs and dyslipidemia. If only unwitnessed cases, less than one hour, n equals 59, were classified as sudden arrhythmic deaths, the sensitivities were 0.18, and specificity was 0.95. The authors concluded that models could identify pre-mortem characteristics to better specify autopsy defined sudden arrhythmic deaths, among presumed sudden cardiac arrests. The authors suggest that the World Health Organization definition can be improved by restricting witnessed sudden cardiac deaths to ventricular tachycardia fibrillation or non-pulseless electrical activity rhythms in unwitnessed cases to less than one hour since last normal, at a cost of sensitivity. In our next paper, Rafael Jaimes III and associates performed optical mapping of trends, membrane, voltage and pacing studies on isolated Langendorff-perfused rat hearts to assess the cardiac electrophysiology after mono-2-ethylhexyl phthalate, a phthalate with documented exposure in intensive care patients. The authors found that a 30-minute exposure to mono-2-ethylhexyl phthalate increased the atrioventricular node effector in period 147 milliseconds compared to 170 milliseconds in controls and increased the ventricular effective refractory periods of 117 milliseconds compared to 77.5 milliseconds in controls. Optical mapping revealed prolonged action potentia

15 MINJUL 16
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Circulation: Arrhythmia and Electrophysiology July 2018 Issue

Circulation: Arrhythmia and Electrophysiology June 2019 Issue

Dr. Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr. Paul Wong, editor-in-chief, with some of the key highlights from this month's issue. In our first paper, Jeremy Wasserlauf and associates compare the accuracy of an atrial fibrillation sensing smartwatch with simultaneous recordings from an insertable cardiac monitor. The authors use smart rhythm 2.0, a convolutional neuro-network, trained on anonymized data of heart rate, activity level and EKGs from 7500 AliveCor users. The network was validated on data collected in 24 patients with insertable cardiac monitor, and a history of paroxysmal atrial fibrillation who simultaneously wore the atrial fibrillation sensing smart watch with smart rhythm 0.1 software. The primary outcome was sensitivity of the atrial fibrillation sensing smart watch for atrial fibrillation episodes of greater than equal to one hour. Secondary end points include sensitivity of atrial fibrillation sensing smart watch for detection of atrial fibrillation by subject and sensitivity for total duration across all subjects. Subjects with greater than 50% false positive atrial fibrillation episodes on insertable cardiac monitor were excluded. The authors analyzed 31,349 hours meaning 11.3 hours per day of simultaneous atrial fibrillation sensing smart watch and insertable cardiac monitor recordings in 24 patients. Insertable cardiac monitor detected 82 episodes of atrial fibrillation of one hour duration or greater while the atrial fibrillation sensing smartwatch was worn. With a total duration of 1,127 hours. Of these, the smart rhythm 2.0 neural network detected 80 episodes. Episode sensitivity 97.5% with total duration 1,101 hours. Duration sensitivity 97.7%. Three of the 18 subjects with atrial fibrillation of one hour or greater had atrial fibrillation only when the watch was not being worn. Patient sensitivity 83.3% or 100% during the time worn. Positive predictive value for atrial fibrillation episodes was 39.9%. The authors concluded that an atrial fibrillation sensing smartwatch is highly sensitive to detection of atrial fibrillation and assessment of atrial fibrillation duration in an ambulatory population when compared to insertable cardiac monitor. In our next paper, Liliana Tavares and associates examine the autonomic nervous system response to apnea in its mechanistic connection to atrial fibrillation. They study the effects of ablation of cardiac sensory neurons with resiniferatoxin, a neurotoxic transient receptor potential vanilloid one agonist. In a canine model, apnea was induced by stopping ventilation until oxygen saturation decreased in 90%. Nerve recordings from bilateral vagal nerves left stellate ganglion and anterior right ganglion plexi were obtained before and during apnea, before and after resiniferatoxin injection in the anterior white ganglion plexi in seven animals. Each refractory period and atrial fibrillation inducibility upon single extra stimulation was assessed before and during apnea, before and after intrapericardial resiniferatoxin administration in nine animals. The authors found that apnea increased anterior wide ganglion plexi activity followed by cluster crescendo vagal bursts synchronized with heart rate and blood pressure oscillation. Upon further oxygen desaturation, a tonic increase in left stellate ganglion activity in blood pressure oscillations ensued. Apnea induced atrial effective refractory shortening from 110 to 90 milliseconds, P less than 0.001 and atrial fibrillation induction in nine animals vs. zero out of nine at baseline. After resiniferatoxin administration increases in ganglion plexi and left stellate ganglion activity, and blood pressure during apnea were abolished, in addition, the atrial effector refractory period increased to 127 milliseconds, P=0.0001 and atrial fibrillation was not induced. Vagal bursts remain unchanged. Ganglion plexi cells showed cytoplasmic microvacuo

17 MINJUN 19
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Circulation: Arrhythmia and Electrophysiology June 2019 Issue

Circulation: Arrhythmia and Electrophysiology May 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, editor-in-chief, with some of the key highlights from this month's issue. In our first article, Daniel Alyesh, Konstantinos Siontis and associates described myocardial calcifications in patients with ischemic cardiomyopathy undergoing ventricular tachycardia ablation in comparison to a control group of patients without ventricular tachycardia. They found that in 56 consecutive post-infarction patients, myocardial calcifications were identified in 39 or 70% of post-infarction ventricular tachycardia patients compared to 6 or 11% of patients without ventricular tachycardia. A calcification volume of 0.538 centimeters cube distinguished patients with calcification-associated ventricular tachycardia from patients without calcification-associated ventricular tachycardias; area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88. A non-confluent calcification pattern was associated with ventricular tachycardia target sites independent of calcification volume, P equals 0.01. Myocardial calcifications corresponding to areas of electrical non-excitability forming a border for re-entry were found in 33% of all ventricular tachycardias for which target sites were identified, and in 62% of patients with myocardial calcifications. In our next paper, Mia Fangel and associates examined whether glycemic status evaluated by hemoglobin A1c has an effect on the risk of thromboembolism among patients with atrial fibrillation and Type 2 diabetes. They used a cohort study from 5,386 patients with incident non-valvular atrial fibrillation and Type 2 diabetes in Danish registries. Compared with patients with hemoglobin A1c of less than or equal to 48 millimole per mole, they observed a higher risk of thromboembolism among patients with hemoglobin A1c 49 to 58 millimoles per mole with a hazard ratio of 1.49 and a hemoglobin A1c greater than 58 millimole per mole with a hazard ratio of 1.59 after adjusting for confounding factors. Surprisingly, in patients with diabetes duration of 10 years or more, higher hemoglobin A1c levels were not associated with a higher risk of thromboembolism. In our next paper, Niek Beurskens and associates compared tricuspid valve dysfunction in leadless pacemaker therapy to dual chamber transvenous pacing systems. They studied 53 patients receiving a leadless pacemaker, including 28 with a Nanostim and 25 with a Micra device. Of these 53 patients, 23 or 43% had tricuspid regurgitation that was graded as being more severe at 12 months. Compared with an apical position, a right ventricular septal position of the leadless pacemaker was associated with increased tricuspid valve incompetence, odds ratio, 5.20; P equals 0.03. An increase in mitral valve regurgitation was observed in 38% of patients. Leadless pacemaker implantation resulted in a reduction of right ventricular function. Leadless pacemaker implantation was further associated with a reduction in left ventricular ejection fraction and elevated LV TI index. The changes in tricuspid regurgitation in leadless pacing group was similar to the changes in dual-chamber transvenous pacemaker group, 43% versus 38% respectively; P equals 0.39. In our next paper, Jurgen Duchenne and associates examined whether regional left ventricular glucose metabolism correlates with regional work in an animal model with reversible dyssynchrony due to pacing. In 12 sheep, after 8 weeks of right atrial and right ventricular free wall pacing, there is evidence of left ventricular dilatation and thinning of the septum and thickening of the lateral wall. The authors employed motion compensation and anatomical correction in order to provide reliable regional estimates of myocardial glucose metabolism. They found that in homogenous regional distribution of myocardial workload due to left bundle branch block triggers adaptive remodeling of the left ventricl

11 MINMAY 22
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Circulation: Arrhythmia and Electrophysiology May 2019 Issue

Circulation: Arrhythmia and Electrophysiology April 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast On the Beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wang, Editor in Chief, with some of the key highlights from this month's issue. In our first paper Lucas Boersma and associates examined the final two-year outcome data from 47 centers, in 1,020 patients receiving the left atrial appendage occlusion watchman devices. Their study population had a mean age of 73.4 years, with 311 having prior ischemic stroke or TIA, 153 having prior hemorrhagic stroke, and 318 having prior major bleeding. 49% had a CHAS II vast score of 5 or greater, and 40% had a HAS-BLED score of three or greater. Oral anticoagulation was contraindicated in 72%. During follow up, 161 patients, or 16.4% died, 22 strokes were observed or 1.3 per 100 patient years representing an 83% reduction versus historic data. And 47 major non-procedural bleeding events were observed, or 2.7 per 100 patient years representing a 46% reduction versus historic data. Device thrombus was observed in 34 patients or 4.1%, and was not correlated to the drug regimen during follow up. P=0.28. In our next paper, Anish Amin and Associates examined whether high voltage impedance and subcutaneous or SICD system implant position are associated with ventricular fibrillation or VF conversion success with a sub-maximal joule shock. In the SICD investigational device exemption study, a successful conversion test required two consecutive VF conversions at 65 joules in either shock vector. Sub-optimal device position was defined as an inferior electrode or pulse generator, or electrode coil depth of greater than three mm anterior to the sternum, based on chest radiograph. Of 314 patients who underwent SICD implantation, 282 patients were included in this analysis. There were 637 inductions to test defibrillation at 65 joules. 62 conversion failures, or 9.7%, occurred in 42 or 14.9% of patients. Lower body mass index or BMI, and lower shock impedance, were associated with higher conversion success rate. Whereas white race was associated with lower conversion success rate. Sub-optimal position was more common in obese patients. Inferior electrode and greater distance between the lead and sternum were associated with a higher impedance. When appropriate system position was achieved, conversion failure was not associated with high BMI. In our next paper, Je-Wook Park and associates examined the left atrial pressure after repeat radiofrequency catheter ablation procedures. Among 1,848 patients who underwent atrial fibrillation or AF catheter ablation, the authors measured the left atrial pressure, LAP, immediately following the transseptal puncture in sinus rhythm in 1,687 patients before De novo ablation, median age 59 years, 72.4% male and 72.8% paroxysmal AF, and in 142 with second procedures. In the same 142 patients, the degree of left atrial stiffness, reflected by LAPP, the difference between LAP peak and LAP nater, was significantly higher in the second procedure than in the De novo procedure. P<0.001. The degree of LAPP increase, delta LAPP, was significantly higher in patients who underwent additional extra pulmonary vein left atrial ablation than in those who underwent circumferential PV isolation alone. P=0.01. Extra pulmonary vein left atrial ablation was independently associated with delta LAPP. P=0.045. An increase LAPP during repeat procedures was independently associated with a reduced diastolic function. P=0.041. However, the EQ5D symptom score did not change after de novo ablation. In our next paper, Adam Graham and associates examined a median of 711 electrocardiographic imaging, or ECGI, in cardiopirin points per patient to compare simultaneous epicardial mapping using CARTO and ECGI after geometrical co registration in 8 patients. They found that the correlation coefficient measuring the similarity of activation times we equal to 0.66, and the correlation coefficient for repolarization times was 0.55.

11 MINAPR 17
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Circulation: Arrhythmia and Electrophysiology April 2019 Issue

Circulation: Arrhythmia and Electrophysiology March 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast "On the Beat" for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, Editor-in Chief, with some of the key highlights from this month's issue. In our first manuscript, Marie Bayer Elming and associates, examined whether the right ventricular ejection fraction can identify patients with non-ischemic systolic heart failure, more likely to benefit from ICD implantation. The Danish study, to assess the efficacy of ICDs in patients with non-ischemic systolic heart failure, on mortality, the Danish study, randomized patients with non-ischemic systolic heart failure to ICD our control. In 239 patients with interpretable cardiovascular magnetic resonance images, the right ventricular volume and ejection fraction was measured. Right ventricular ejection fraction was an independent predictor of all-cause mortality, with a hazard ration 1.34 per 10% absolute decrease in our right ventricular ejection fraction. P=0.02. There is statistically significant interaction between right ventricular ejection fraction and the effect of ICD implantation. P=0.001. ICD implantation significantly reduced all-cause mortality in patients with right ventricular systolic dysfunction. Hazard ratio 0.41, but not in patients without right ventricular systolic dysfunction. Thus, in this post-hoc analysis of the Danish trial, ICD therapy was associated with survival benefit in patients with bi-ventricular heart failure. In our next paper, Dawn Pedrotty and Volodymyr Kuzmenko and associates, have proposed a concept of using a stretchable, flexible, bio patch, with conductive properties, to attempt to restore conduction across regions in which activation is disrupted. They use carbon nanotube patches, composed of nanofibrillated cellulose, in single wall carbon nanotube ink, 3-D printed in conductive patterns onto bacterial nanocellulose. Electro anatomic mapping was performed on normal epicardium and repeated over surgically disruptive epicardium, and finally with the patch applied passively. The patch resulted in restored conduction based on mapping. In our next paper, Ayman Hussein and colleagues developed a fully automated platform to collect patient reported outcomes in a prospective cohort of atrial fibrillation ablation. Two thousand one hundred and seventy-five patients were eligible to receive 10,903 patient reported outcome assessment invitations. More follow up assessments were obtained with automated patient reported outcomes in routine follow-up, compared with routine follow up alone, P > 0.001, which allowed for longer duration of follow up, 378 vs 217 days. By automated patient reported outcomes, a large number of disease specific variables were collected and showed improvement in quality of life. Baseline median AF symptom severity score of 12 and ranged between 2 and 3 on subsequent assessments, P > 0.0001. This improvement was also true for each of the atrial fibrillation symptom severity score components. In patient reported outcomes, there was a significant reduction in atrial fibrillation burden, such as frequency and duration episodes and associated healthcare utilization including emergency visits and hospitalizations after the ablation procedures. In our next paper, Nicolas Johner, Dipen Shah, and associates, examined the role of post pacing intervals shorter than tachycardia cycling during entrainment mapping. The author studied 24 non-cavotricuspid isthmus dependent macro oriented atrial flutters in 19 consecutive patients. High density electro anatomic activation maps were acquired with a 64-electrode basket catheter of 102 entrainment mapping sites. Post pacing interval difference less than 30 was observed at 72 sites on complete maps of 24 atypical atrial flutters compared to sites with the difference in post pacing intervals 0 to 30, with 45 sites difference in the post pacing interval less than 0 at 27 were more commonly located within isthmuses less than 15mm wid

15 MINMAR 25
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Circulation: Arrhythmia and Electrophysiology March 2019 Issue

Circulation: Arrhythmia and Electrophysiology February 2019 Issue

Dr Paul Wong: Welcome to the monthly podcast on the beat for Circulation: Arrhythmia and Electrophysiology. I'm Dr Paul Wong, Editor-in Chief with some of the key highlights from this month's issue. This month's issue is dedicated to a new exciting topic, His bundle pacing. His bundle pacing is designed to achieve a more physiological human dynamic response than right ventricular pacing alone, which may be needed in patients with AV conduction abnormalities. In our first paper, Marek Jastrzebski and associates examined whether program stimulation may be used to distinguish nonselective His bundle capture from right ventricular myocardial capture. Premature beats were introduced at 10 millisecond steps during intrinsic rhythm, and also after a drive train of 600 milli seconds. The longest coupling interval that resulted in an abrupt change in the QRS morphology was considered equal to the effective refractory period of the His bundle or right ventricular myocardium. Program His bundl...

9 MINFEB 20
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Circulation: Arrhythmia and Electrophysiology February 2019 Issue

Circulation: Arrhythmia and Electrophysiology january 2019 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat, for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, Editor-in-Chief, with some of the key highlights from this month's issue. Koji Miyamoto and associates conducted the AD-Balloon Study, which investigates the ideal number of free cycles during second-generation cryoballoon pulmonary vein isolation. In a prospective, multicenter, randomized clinical trial, the authors compared in 110 patients the addition of a three minute freeze after pulmonary vein isolation had been achieved to pulmonary vein isolation alone. Delayed-enhancement magnetic resonance imaging was also performed one to two months after the pulmonary vein isolation to assess the ablation lesions. The freedom from atrial arrhythmias at one year was similar. Log rank test, P equals 0.78 in the two groups, 87.3% in the extra three-minute freeze group, and 89.1% in the pulmonary vein isolation group. There was no significant difference in the freq...

11 MINJAN 16
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Circulation: Arrhythmia and Electrophysiology january 2019 Issue

Circulation: Arrhythmia and Electrophysiology December 2018 Issue

Dr Paul Wang: Welcome to the monthly podcast, On the Beat for Circulation: Arrhythmia, and Electrophysiology. I'm Dr Paul Wang, editor in chief, with some of the key highlights for this month's issue. In our first paper, Pasquale Vergara and Associates develop a predictive risk score to assess the outcome of ventricular tachycardia ablation creating what they call the IVT score. The authors examined 16 demographics, clinical, and procedural related variables in 1,251 patients. They used a technique called survival tree analysis, which uses a recursive partitioning algorithm to find relationships among variables. They then compared the survival time and time to VT recurrence in groups derived from survival tree analysis using a log rank test. A random forest analysis was then run to extract a variable importance index and internally validate the survival tree models. They found that the left ventricular ejection fraction, ICD, or CRT device, previous ablation were the best predictors...

14 MIN2018 DEC 19
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Circulation: Arrhythmia and Electrophysiology December 2018 Issue