Xiaodong Zhang1, MD, PhD, Ruike Yang1 2, MD, Luigi Di Biase1, MD, PhD, FHRS1 Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York2 Division of Cardiology, Department of Medicine, Henan Provincial People’s Hospital, Zhengzhou, ChinaCorrespondence : Dr Luigi Di Biase, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th St, Bronx, NY 10467. E-mail address: [email protected] .Keywords : narrow complex tachycardia, dual atrioventricular nodal non-re-entrant tachycardia, dual atrioventricular nodal re-entrant tachycardia, autonomic nervous system

EP Rounds

Underrecognized consequence of three-dimensional mapping tool selection for atrial fibrillation ablation: when the operators’ decision determines the amount of silent micro-embolic burden Thomas Rostock MD, Torsten Konrad MD, Raphael Spittler MDFrom the University Hospital Mainz, Center for Cardiology,Cardiology II / Electrophysiology, Mainz, GermanyWord count: 1460Funding: (None)Disclosures: (None)

EDITORIAL: Modern Atrial Fibrillation Care: Becoming a Pro at Using PROsSamuel F. Sears, PhD,1,2 Scarlett Anthony, BA,1 & Aditi Naniwadekar, MD21 Department of Psychology, East Carolina University, Greenville, NC2 Department of Cardiovascular Sciences, Brody School of Medicine, East Carolina University, Greenville, NC

Rate dependent exit block across the pulmonary veins has been previously described immediately following catheter ablation. We report the case of rate dependent PV block seen at repeat ablation 7 years after the index procedure. To our knowledge, this is the first report of chronic rate dependent exit block (i.e. Rate dependent exit block discovered 7 years after circumferential PV antral isolation). We believe that, as with CTI ablation, rate independent pulmonary vein isolation should be confirmed.

HCM is associated with an increased risk of various cardiac arrhythmias, including atrial fibrillation (AF), nonsustained ventricular tachycardia (NSVT), and sustained ventricular tachycardia (VT). Furthermore, the presence of cardiac arrhythmias has an important effect on the prognosis of HCM patients, especially with respect to ventricular arrhythmias as a major cause of sudden cardiac death (SCD). In this issue of Journal of Cardiovascular Electrophysiology, Magnusson and Mörner describe the incidence of NSVT, AF, and bradycardia in thirty patients at relatively low risk of SCD by utilizing an implantable cardiac monitor (ICM). These data are useful in demonstrating a fairly significant arrhythmia burden in a low risk population. The ramifications of these findings are a bit unclear, however. Certainly, atrial fibrillation is important to detect in order to mitigate the increased stroke risk by instituting anticoagulation. Detection of NSVT was less useful in this low risk population, but could be potentially more actionable in intermediate risk HCM patients. Thus, although further investigation is needed, the authors have taken the first step in determining appropriate treatment strategies for arrhythmias in HCM by helping to define the scope of the problem.

Dealing with RV-oversensing; separate sensitivity settings for brady and tachy sensingPranav Bhagirath MD PhD1, Kyle Beunder BSc1, Vokko van Halm MD PhD11Department of Cardiology, Amsterdam University Medical Center, Amsterdam, the NetherlandsFunding: (None)Disclosures: (None)

Sustained ventricular tachycardia and ventricular fibrillation (VF) are life-threatening arrhythmias which remain highly prevalent in patients with advanced heart failure. These ventricular arrhythmias may impair the support provided by CF-LVADs and lead to frequent hospitalizations, antiarrhythmic medication use, external defibrillations, and need for heart transplantation. We report a case in which a patient with a CF-LVAD and an ICD at end-of-life (EOL) presented with asymptomatic low-flow alarms and was found to have VF of unknown duration. Unique in our case was the presence of organized contractility and rhythmic opening of the mitral valve on echocardiogram despite VF on ECG.

Background: Powered transvenous lead extraction (TLE) tools are commonly required to remove the leads that have long implant duration due to fibrotic adhesions. However, comparative data are lacking among different types of TLE tools. Aim: To compare the efficacy and safety of two different rotational mechanical dilator sheaths in retrospectively analyzed patients who underwent TLE. Methods and results: A total of 566 lead extractions from 302 patients using TightRailTM (333 lead extractions from 169 patients) and Evolution® (233 lead extractions from 133 patients) mechanical dilator sheaths were performed between July 2009 and June 2018. Acute and long term outcomes of study groups were compared. There is no statistically significant difference between Evolution® and TightRailTM groups in procedural success (93.9% vs. 94%), clinical success (99.2% vs. 98%) and major complications (3.8% vs. 1.2%), respectively (p>0.05). In multivariate regression analysis, lead dwell time, the number of extracted leads, and baseline leukocyte count was found as independent predictors of procedural success (p<0.05). During the median follow-up of 36.6 (0.2-118) months, all-cause mortality was observed in 73 patients (25.6% in the Evolution® vs. 23.1 in the TightRailTM group, p>0.05). Chronic renal disease, heart failure, and coagulopathy were shown as independent predictors of all-cause mortality in multivariate regression analysis (p<0.05). Conclusions: TLE using TightRailTM or Evoluation® mechanical dilator sheaths is a safe and effective therapeutic option. Both mechanical dilator sheaths showed similar efficacy, safety, and all-cause mortality at acute and long-term follow-up of patients who underwent TLE.

We introduced a simple technique to eliminate electromagnetic interference between a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD). A 43-year-old male with heart failure and a reduced ejection fraction (HFrEF) who had an ICD presented with decompensated heart failure and received an LVAD as a bridge to transplant. Remote monitoring showed persistent atrial fibrillation causing an inappropriate ICD shock leading to a decision to disable shock therapies. However, an in-office interrogation was unsuccessful due to electromagnetic interference. Patient was instructed to extend his arm above his head on the ipsilateral side of the ICD, thus increasing the distance between LVAD and ICD, eliminating the interaction to allow reprogramming of the device.

Wide complex tachycardia with changing QRS-axis on loop recorderShort title: QRS-axis changes on loop recorder

Introduction: Presence of preferential pathway conduction is mostly detected as fractionated presystolic potentials preceding the QRS onset during premature ventricular contractions (PVCs) and late potentials during sinus rhythm (SR), but the electrophysiologic mechanisms and significance of these potentials have not been fully clarified. We describe a PVC case series in which the preferential pathway conduction was 3-dimensionaly visualized by coherent mapping with the conduction velocity vector. Methods: Five PVCs (2 from the left coronary cusp, 2 from the commissure of the left and right coronary cusps, and 1 from the pulmonary artery) in 4 patients for which a fractionated presystolic potential during the PVCs and late potential during SR were recorded at the successful ablation site were reviewed, and 3-dimensional coherent activation maps with the conduction velocity vector during the PVCs and SR were reconstructed. Results: At the successful ablation site, an “M”-shaped discrete presystolic-potential and “W”-shaped discrete late-potential were recorded in all patients. The configuration of the flipped electrogram of the presystolic-potential nearly matched that of the electrogram exhibiting the late-potential. We created coherent activation maps annotating the onset of the presystolic potentials during the PVCs, and the offset of the late potentials during SR, which suggested bidirectional conduction of the preferential pathway connecting the PVC origin to the myocardium. Conclusion: In this case series, the M-shaped presystolic potential and W-shaped late potential were reversely matched. These reverse potentials, and the coherent activation vector maps during PVCs and SR suggested bidirectional conduction of the preferential pathway in opposite directions.

Introduction: Elevated left atrial pressure (LAP) during catheter ablation of atrial fibrillation (AF) is associated with an increased risk of AF recurrence, but it is unknown if this correlates with heart failure (HF). The objective of the study was to determine if elevated LAP after AF ablation correlates with HF events. Methods: Prospective, single center, cohort study measuring LAP and RAP during AF ablation in 100 patients. The primary endpoint was clinical HF within 30 days of ablation. The secondary outcome was AF-free HF. Results: 100 patients (63% male, mean age 64.5) were enrolled and 20% had clinical HF within 30 days. Bivariate correlates included mitral valve (MV) disease, persistent AF, class III antiarrhythmics, LAP, and recurrent AF. Multivariate analysis revealed class III antiarrhythmics were protective (OR 0.24 [0.1–0.5], p=0.04), while MV disease (OR 8.7 [3.3—23], p=0.03) and loop diuretics (OR 4.8 [2.6–9.1], p=0.01) were hazardous. AF-free HF occurred in 9% of patients and correlated with higher LAP and RAP, and CKD. Conclusion: Patients with HF after AF ablation had higher LAP. MV disease, diuretic use, and class III antiarrhythmics also correlated to HF. These present opportunities to target future interventions to reduce a common complication of AF ablation.

RESPONSE FOR THE LETTER TO THE EDITORDon’t miss a chance taking the best shot!!Kunihiko KiuchiDivision of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of MedicineAddress for correspondence:Kunihiko Kiuchi, MD, FHRSSection of Arrhythmia, Division of Cardiovascular Medicine,Department of Internal Medicine, Kobe University Graduate School of Medicine7-5-2 Kusunoki-chou chuou-ku, Kobe, Hyogo, JapanTelephone: (81)-78-382-5846Fax: (81)-78-382-5859E-mail: [email protected]:The Section of Arrhythmia was supported by an endowment from Medtronic JAPAN and Abbott JAPAN. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.Funding: NoneTo the Editor,We thank Dr. Althoff and Mont for their interest, comments, and suggestions related to our paper.1 In our study, as they suggested, LGE-MRI was acquired 1-3 months after the ablation. An animal study reported that ablation lesions are fully formed by 3 weeks and are dense with collagen and fat deposition by 6 weeks.2 In our pilot study, the ablation lesion area dramatically diminished from 1 week to 6 weeks after the procedure in most of the patients. Furthermore, the ablation lesion area was comparable between 6 weeks and just 3 months after the ablation. Of interest, the ablation lesion disappeared after 5-6 months following the procedure in some patients without AF recurrence. We speculated that the shrinkage of the ablation lesion might have occurred during the pathophysiological healing process and reverse remodeling of the left atrium. Therefore, we considered that the time point of taking the “best shot” might have been earlier than we expected. Furthermore, the dose of the contrast agent was important for determining the time point. Our dose of the contrast agent was 0.1mmol/kg, which was relatively lower than that of the other groups. To address this issue, further study will be needed.As for an internal reference for normalization, the threshold of the signal intensity was initially determined according to the signal intensity histogram on the “whole LA wall” in our previous studies.3,4 However, as the authors suggested, neither the ablation lesion nor atrial fibrosis could be accurately visualized in some patients with advanced atrial remodeling. Therefore, the internal reference was changed from the “whole LA wall” to the “healthy LA wall” in our recent studies.1,5 We believed that this simple but important tip might make it possible to sensitively identify pre-existing atrial fibrosis, particularly interstitial fibrosis. The signal intensity of ablation lesion was significantly higher than that of the pre-existing atrial fibrosis. Our question is whether the ablation lesion characteristics dramatically differed between the different references in patients without atrial remodeling. Although we re-analyzed the LGE-MRI with two different references (“whole LA wall” and “healthy LA wall”), no significant difference in the lesion characteristics could be found. Cryoballoon ablation and RF ablation with contact-force sensing catheter induced intensive inflammation which followed by the artificial fibrosis.6 In this study, we focused on the visualization of the ablation lesion not the pre-existing atrial fibrosis, and patients without atrial remodeling were enrolled. We considered that the impact of the difference in the reference could be less than we expected, when we focused on the ablation lesions in patients without atrial remodeling.To visualize the atrial fibrosis and the ablation lesion, different visualization methods were developed. However, very few histological validations could be found. Furthermore, the dose of the contrast agents, MRI system, and visualization software completely differed due to the regulations in each institution. Therefore, it is not surprising that the image differed between each visualization technique. It is important to note the reproducibility of the visualization method and clinical implication of the best shot. The authors had already reported the reproducibility of their method.7 However, this issue is still in debate.8 We would like to challenge to improve the quality of our “best shot” and strengthen both reproducibility and clinical implication in a further study.References1. Kurose J, Kiuchi K, Fukuzawa K, et al. Lesion characteristics between cryoballoon ablation and radiofrequency ablation with a contact-force sensing catheter: late-gadolinium enhancement magnetic resonance imaging assessment. J Cardiovasc Electrophysiol. 2020.2. Avitall B, Kalinski A. Cryotherapy of cardiac arrhythmia: From basic science to the bedside. Heart Rhythm. 2015;12(10):2195-2203.3. Shigenaga Y, Kiuchi K, Ikeuchi K, et al. Fusion of Delayed-enhancement MR Imaging and Contrast-enhanced MR Angiography to Visualize Radiofrequency Ablation Scar on the Pulmonary Vein. Magn Reson Med Sci. 2015;14(4):367-372.4. Kiuchi K, Okajima K, Shimane A, et al. Visualization of the radiofrequency lesion after pulmonary vein isolation using delayed enhancement magnetic resonance imaging fused with magnetic resonance angiography. J Arrhythm. 2015;31(3):152-158.5. Akita T, Kiuchi K, Fukuzawa K, et al. Lesion distribution after cryoballoon ablation and hotballoon ablation: Late-gadolinium enhancement magnetic resonance imaging analysis. J Cardiovasc Electrophysiol. 2019.6. Kiuchi K, Fukuzawa K, Mori S, Watanabe Y, Hirata KI. Feasibility of Imaging Inflammation in the Left Atrium Post AF Ablation Using PET Technology. JACC Clin Electrophysiol. 2017;3(12):1466-1467.7. Benito EM, Carlosena-Remirez A, Guasch E, et al. Left atrial fibrosis quantification by late gadolinium-enhanced magnetic resonance: a new method to standardize the thresholds for reproducibility.Europace. 2017;19(8):1272-1279.8. Kamali R, Schroeder J, DiBella E, et al. Reproducibility of Clinical Late Gadolinium Enhancement Magnetic Resonance Imaging in Detecting Left Atrial Scar after Atrial Fibrillation Ablation. J Cardiovasc Electrophysiol. 2020 in press.

A document by William Chan. Click on the document to view its contents.

Objective: To determine trends in real-world utilization and in-hospital adverse events from Watchman implantation since its approval by the Food and Drug Administration in 2015. Background: The risk of embolic stroke caused by atrial fibrillation is reduced by oral anticoagulants, but not all patients can tolerate long-term anticoagulation. Left atrial appendage occlusion with the Watchman device has emerged as an alternative therapy. Methods: This was a retrospective cohort study utilizing data from National Inpatient Sample for calendar years 2015-2017. The outcomes assessed in this study were associated complications, in-hospital mortality, and resource utilization trends after Watchman implantation. Trends analysis were performed using analysis of variance. Multivariable adjusted logistic regression analysis was performed to determine predictors of mortality. Results: A total of 17,700 patients underwent Watchman implantation during the study period. There was a significantly increased trend in the number of Watchman procedures performed over the study years (from 1,195 in 2015 to 11,165 devices in 2017, p < 0.01). A significant decline in the rate of complications (from 26.4% in 2015 to 7.9% in 2017, p < 0.01) and inpatient mortality (from 1.3% in 2015 to 0.1% in 2017, p < 0.01) were noted. Predictors of in-hospital mortality included a higher CHA₂DS₂-VASc score (OR 2.61 per 1-point increase, 95% CI 1.91-3.57), chronic blood loss anemia (OR 3.63, 95% CI 1.37-9.61) and coagulopathy (OR 4.90, 95% CI 2.32-10.35). Conclusion: In contemporary United States clinical practice, Watchman utilization has increased significantly since approval in 2015, while complications and in-patient mortality have declined.

Coronary artery injury is a rare complication of catheter ablation in the right ventricular outflow tract (RVOT). Furthermore, acute myocardial ischemia usually causes polymorphic ventricular tachycardia (VT) or ventricular fibrillation. We herein describe a case in which catheter ablation for VT originating from the RVOT provoked ischemia-related VTs due to acute occlusion of the left anterior descending artery.

Is Otsu Thresholding the Answer to Reproducible Quantification of Left Atrial Scar from Late Gadolinium-Enhancement MRI?Suvai Gunasekaran, PhDa, Daniel Kim, PhDa,ba Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United Statesb Department of Biomedical Engineering, Northwestern University, Evanston, IL, United StatesPlease send correspondence to:Daniel Kim, PhDDepartment of RadiologyNorthwestern University737 N. Michigan Avenue Suite 1600Chicago, IL 60611 [email protected] O:312.926.1733 F:312.926.5991