Faculty Bibliography

Occult atrial fibrillation (AF) can be the underlying cause for cryptogenic stroke (CS). Implantable loop recorders (ILRs) have become an important tool for long-term arrhythmia monitoring in CS patients. Office-based ILR implantation by nonelectrophysiologist physicians is increasingly common. To report the real world diagnostic yield and accuracy of remote ILR monitoring in high risk CS patients, we retrospectively analyzed 145 consecutive patients with CS who underwent ILR implantation between October 2014 and October 2018 at New York University Langone Health. A certified device technician and an electrophysiologist adjudicated all transmissions. The yield and accuracy of Reveal LINQ Intra Cardiac Monitor (ICM), a fourth generation device, was compared to that of TruRhythm Detection algorithm (fifth generation device). AF was diagnosed in 17 patients (12%) over a mean follow-up of 28 ± 12 months. The median time to diagnosis was 7.4 ± 21.3 months. A total of 1,637 remote transmissions (scheduled- and auto-triggered alerts: 756; patient-triggered: 881) were adjudicated. The positive predictive value for AF episodes in the scheduled interrogations increased from 4% in the Reveal LINQ ICM to 16% in the TruRhythm LINQ. Of 881 patient-triggered transmissions, none were found to be true positive. In the Reveal LINQ ICM, for scheduled transmissions, primary causes of false positive (FP) were atrial ventricular premature complexes (80%). In the TruRhythm LINQ, for scheduled transmissions, primary cause of FP were T-wave over-sensing (87%). In conclusion, the real world diagnostic yield of ILR for patients with CS remains suboptimal, with at least 84% of AF alerts being FP. Patient-riggered events did not correlate with arrhythmia and the necessity of patient triggering in this population should be questioned. Expert interpretation of recordings is critical to assure accurate diagnosis.

INTRODUCTION/BACKGROUND:Catheter stability during atrial fibrillation ablation is associated with higher ablation success rates. Rapid cardiac pacing and high frequency jet ventilation (HFJV) independently improve catheter stability. Simultaneous modulation of cardiac and respiratory motion has not been previously studied. The objective of this study was to determine the effect of simultaneous heart rate and respiratory rate modulation on catheter stability. METHODS:Forty patients undergoing paroxysmal atrial fibrillation ablation received ablation lesions at 15 pre-specified locations (12 left atria, 3 right atria). Patients were randomly assigned to undergo rapid atrial pacing for either the first or the second half of each lesion. Within each group, half of patients received HFJV and half standard ventilation. Contact force and ablation data for all lesions were compared among the study groups. Standard deviation of contact force was the primary endpoint defined to examine contact force variability. RESULTS:Lesions with no pacing and standard ventilation had the greatest contact force standard deviation (5.86 + 3.08g), compared to lesions with pacing and standard ventilation (5.45+3.28g, p<0.01) or to lesions with no pacing and HFJV (4.92+3.00g, P<0.01). Lesions with both pacing and HFJV had the greatest reduction in contact force standard deviation, (4.35+2.81g, p<0.01), confirming an additive benefit of each maneuver. Pacing and HFJV together was also associated with a reduction in the proportion of lesions with excessive maximum contact force (p<0.001). DISCUSSION/CONCLUSIONS:Rapid pacing and HFJV additively improve catheter stability. Simultaneous pacing with HFJV further improves catheter stability over pacing or HFJV alone to optimize ablation lesions. This article is protected by copyright. All rights reserved.

Conducted energy weapon (commonly known as TASER) discharge in patients with implantable cardioverter-defibrillators is known to cause electromagnetic interference and inappropriate ventricular fibrillation sensing without delivery of implantable cardioverter-defibrillators therapy during conducted energy weapon application. We report the first known case of conducted energy weapon discharge resulting in inappropriate implantable cardioverter-defibrillators therapy. (Level of Difficulty: Beginner.).

INTRODUCTION/BACKGROUND:Clinical trials have failed to reliably show improved outcomes with utilization of contact-force sensing (CFS) radiofrequency (RF) ablation catheters. It is unknown whether the unfavorable outcomes observed in these trials are attributable to inexperience with CFS technology. OBJECTIVES/OBJECTIVE:To compare catheter ablation outcomes of stepwise linear ablation with versus without CFS technology and to assess the impact of operator experience with CFS technology on procedural outcomes. METHODS:Clinical outcomes were evaluated in 228 consecutive NPAF patients undergoing first-time left atrial ablation using a stepwise linear approach. Arrhythmia recurrence was assessed using 2-week event monitors at 3-month intervals following index ablation. RESULTS:A total of 228 patients were included in our study. There was no statistically significant difference in risk of recurrent atrial arrhythmias at 12 and 24 months between CFS and non-CFS patients (p = 0.5 and p = 0.169). The time to recurrence of atrial arrhythmias at 24 months in the second half of CFS patients was significantly lower when compared to both the first half of CFS patients (p = 0.002) and non-CFS patients (p = 0.005). CONCLUSION/CONCLUSIONS:While there was no difference in overall outcomes between CFS and non-CFS ablation using a stepwise linear approach in patients with NPAF, procedural efficacy of the second half of CFS patients was significantly improved compared to both the first half of CFS patients and all non-CFS patients. Lack of benefit seen in clinical trials using CFS technology may be related to operator inexperience with CFS ablation catheters at the time of the trials.

INTRODUCTION/BACKGROUND:Acute hemopericardium during cardiac electrophysiology (EP) procedures may result in significant blood loss and is the most common cause of procedure related death. Matched allogeneic blood is often not immediately available. The feasibility and safety of direct autotransfusion in cardiac electrophysiology patients requiring emergency pericardiocentesis is unknown. METHODS:We retrospectively analyzed records of patients undergoing EP procedures at a single, tertiary care medical center who had procedure-related acute hemopericardium requiring emergency pericardiocentesis during a three-year period. Procedure details, transfusion volumes, and clinical outcomes of patients who received direct autotransfusion of aspirated pericardial blood via a femoral venous sheath were compared to those of patients who did not receive direct autotransfusion. RESULTS:During the study period, 10 patients received direct autotransfusion (group 1) and outcomes were compared with those of 14 control patients who did not receive direct autotransfusion (group 2). Volume of aspirated pericardial blood was similar in groups 1 and 2 (1.6±0.7 L vs. 1.3±1.0 L, respectively; p=0.52). Amongst patients with aspirated volumes < 1L, group 1 patients (n=4) were less likely than group 2 patients (n=8) to require allotransfusion (0% vs. 75%, p=0.02). Amongst patients with aspirated volume ≥ 1L, group 1 patients (n=6) required fewer units of red cell allotransfusion than group 2 patients (n=6) (1.5±0.8u vs. 4.3±2.0u, p=0.01). No procedural complications related to direct autotransfusion occurred. CONCLUSIONS:Direct autotransfusion following emergency pericardiocentesis during electrophysiology procedures requiring systemic anticoagulation is feasible and safe. Utilization of direct autotransfusion may eliminate or reduce the need for allotransfusion. This article is protected by copyright. All rights reserved.

INTRODUCTION/BACKGROUND:Implantable cardioverter defibrillators (ICDs) are proven to prevent sudden death in patients at elevated risk for sustained ventricular tachycardia or fibrillation. Complications related to ICD failure can stem from lead dysfunction, manufacturing defects, patient characteristics or implantation technique. We conducted a review of all ICD leads implanted at our center from 2011-2017 to determine risk factors for premature lead failure. METHODS:We conducted a retrospective review of patients of all ICD leads implanted from December 2011 to June 2017 at our institution. A total of 660 patients (Biotronik Linox S/SD, n = 281; Sprint Quatro, n = 207; Durata, n = 121; Endotak, n = 51) underwent ICD implantations. Patient and lead characteristics, procedural outcomes and complications were recorded. Lead failure was defined per Heart Rhythm Society lead-management consensus as a lack of procedural or clinical success, thus requiring an extraction of the lead. Patient and lead outcomes were recorded and variables associated with lead failure were assessed by the Kaplan-Meier method. RESULTS:Overall failure rate was similar for all leads: Linox S/SD - 0.29%/year; Sprint Quattro - 0.21%/year, Durata - 0.39%/year and Endotak Reliance - 0.0% (p=0.769). No difference was found in overall survival when comparing all ICD manufacturers during the study period. Subgroup analysis revealed the risk of premature lead failure was particularly pronounced in multi-lead ICD systems implanted via cephalic access (p<0.001). The estimated failure rate of Linox leads implanted via cephalic access in multi-lead systems was 19%/year. The estimated failure rate of non-Linox leads implanted via cephalic access in multi-lead systems was 11%/year. Neither age, nor gender were risk factors for lead failure in the Linox, or non-Linox cohorts. CONCLUSION/CONCLUSIONS:All analyzed ICD leads were found to have a similar overall risk of premature failure. ICD lead implantation via cephalic access in multilead ICD systems may be a previously unidentified risk factor for premature ICD lead failure, although these findings require further validation. This article is protected by copyright. All rights reserved.

BACKGROUND:Increased peak luminal esophageal temperature (LET) is associated with increased risk of esophageal injury following left atrial posterior wall (LAPW) ablation. The magnitude, distribution, and risk factors of LET increase with high power short duration (HPSD) LAPW ablation are not well understood. OBJECTIVE:We aimed to describe the spatial and temporal characteristics of LET changes associated with HPSD LAPW RFA. METHODS:LET was sampled at 20Hz using a 12-point esophageal temperature monitor (CIRCA S-CATH, Circa Scientific, Inc.) in 16 patients undergoing LAPW ablation. Esophageal temperature sensor position and lesion locations were recorded using an electroanatomic mapping system with fluoroscopic integration (CARTO 3, CARTOUNIVU, Biosense Webster, Inc). Point-by-point LAPW ablation was performed at 50W for 6s. The first 20 LAPW lesions were individually analyzed in each patient. RESULTS:LET increase ≥4°C (8 lesions: Max LET 5.8°C), 2-4°C (34 lesions), and 1-2°C (58 lesions) occurred at 9±2 mm, 8±2 mm, and 13±2mm from sensors, respectively. Lesions placed >20mm from a temperature sensor did not result in an LET increase ≥2°C. Temperature resolution to within 1°C of baseline occurred at ∼60s after cessation of RF. Consecutive lesions resulting in additive heating of at least 1°C occurred in 17 lesion pairs with an inter-lesion distance of 9±4mm and inter-lesion time of 21±4s. CONCLUSION/CONCLUSIONS:HPSD LAPW ablation can result in severe esophageal temperature increases. Significant LET increase will be undetected when lesions are >20mm away from a temperature sensor. Additive LET increase was observed with consecutive lesions placed less than 20mm apart within 60s.

BACKGROUND:Optimal ablation technique, including catheter-tissue contact during atrial fibrillation (AF) radiofrequency (RF) ablation, is associated with improved procedural outcomes. We used a custom developed software to analyze high-frequency catheter position data to study the interaction between catheter excursion during lesion placement, lesion-set sequentiality, and arrhythmia recurrence. METHODS:A total of 100 consecutive patients undergoing first-time RF ablation for paroxysmal AF were analyzed. Spatial positioning of the ablation catheter sampled at 60 Hz during RF application was extracted from the CARTO3 system (Biosense Webster Inc, USA) and analyzed using custom-developed MATLAB software to determine precise catheter spatial 3D excursion during RF ablation. The primary end point was freedom from atrial arrhythmia lasting longer than 30 seconds after a single ablation procedure. RESULTS:At 1 year, 86% of patients were free from recurrent arrhythmia. There was no significant difference in clinical, echocardiographic, or ablation characteristics between patients with and without recurrent arrhythmia. Analyzing 15,356,998 position data points revealed that lesion-set sequentiality and mean lesion catheter excursion were predictors of arrhythmia recurrence. Analyzing arrhythmia recurrence by mean single-lesion catheter excursion (excursion >2.81 mm) and by sequentiality (using 46% of lesions with interlesion distance >6 mm as cutoff) revealed significantly increased arrhythmia recurrence in the higher excursion group (23% vs 6%, P = .03) and in the less sequential group (24% vs 4%, P = .02). CONCLUSIONS:Ablation lesion sequentiality measured by catheter interlesion distance and catheter stability measured by catheter excursion during lesion placement are potentially modifiable factors affecting arrhythmia recurrence after RF ablation for AF.

OBJECTIVES/OBJECTIVE:This study sought to determine whether a radiation safety time-out reduces radiation exposure in electrophysiology procedures. BACKGROUND:Time-outs are integral to improving quality and safety. The authors hypothesized that a radiation safety time-out would reduce radiation exposure levels for patients and the health care team members. METHODS:The study was performed at the New York University Langone Health Electrophysiology Lab. Baseline data were collected for 6 months prior to the time-out. On implementation of the time-out, data were collected prospectively with analyses to be performed every 3 months. The primary endpoint was dose area product. The secondary endpoints included reference point dose, fluoroscopy time, use of additional shielding, and use of alternative imaging such as intracardiac and intravascular ultrasound. RESULTS:, representing a 21% reduction (p = 0.007). The median reference point dose prior to time-out was 163 mGy, and during the time-out was 122 mGy (p = 0.011). The use of sterile disposable protective shields and ultrasound imaging for access increased significantly during the time-out. CONCLUSIONS:A radiation safety time-out significantly reduces radiation exposure in electrophysiology procedures. Electrophysiology laboratories, as well as other areas of cardiovascular medicine using fluoroscopy, should strongly consider the use of radiation safety time-outs to reduce radiation exposure and improve safety.