Faculty Bibliography

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: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.

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.

Background: Left atrial posterior wall (LAPW) isolation is associated with favorable outcomes for catheter ablation of persistent atrial fibrillation (AF) in several studies. Reported techniques for LAPW isolation include ablation at the periphery without ablation within the LAPW, and high density ablation of all sites of electrical activity within the LAPW. The proportion of LA isolated by the lesion set in various reports also varies greatly. The optimal technique to achieve LAPW isolation is not clear.
Objective(s): To assess impact of ablation lesion density within the LAPW and dimensions of LAPW isolation region on arrhythmia recurrence in catheter ablation of persistent AF.
Method(s): LAPW lesion density, and LAPW isolation surface area relative to total LA surface area were calculated using electroanatomic maps of 110 consecutive patients undergoing LAPW isolation for persistent AF (CARTO 3, Biosense Webster, Inc.) LAPW isolation lesion sets were created at the discretion of 5 experienced operators after LA voltage mapping. LAPW and PV entrance block and exit block were confirmed. Arrhythmia recurrence at one year was assessed by the Kaplan-Meier method.
Result(s): LAPW lesion density ranged from 0% - 99%. Proportion of LA surface area isolated ranged from 35% - 75%. There was no significant difference in arrhythmia-free survival by quartile of LAPW ablation density (81% vs. 68% vs. 85% vs. 78%, p=0.8), or by quartile of LA surface area proportion isolated (85% vs. 75% vs. 79% vs. 74%, p=0.3). Voltage map guided LAPW isolation resulted in no significant difference in incidence of recurrent arrhythmia by quartile of total LA surface area (81% vs. 78% vs. 78% vs. 74%, p=0.5).
Conclusion(s): Neither the density of ablation within the LAPW nor the dimensions of the isolated region predicted arrhythmia-free survival LAPW isolation for catheter ablation of persistent AF. Voltage map guided LAPW isolation resulted in similar ablation efficacy regardless of LA size.
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Background: The rapid increase in the number and complexity of electrophysiology (EP) procedures performed annually requires improved strategies to safely enhance post procedural monitoring and early discharge.
Objective(s): To determine if a wearable device that continuously and non-invasively measures vital signs and hemodynamic parameters can predict post-procedure cardiovascular decompensation.
Method(s): Investigator initiated, prospective study of 21 patients receiving either atrial fibrillation ablation (N=16) or device implantation (N=5). Patients were monitored for the post-procedure time periods ranging from 8 to18 hours with two techniques: 1) sporadic measurements with a conventional vital sign monitor; and 2) continuous measurements with toSense's CoVaTM Monitoring System, an FDA-cleared wearable device measuring stroke volume (SV), cardiac output (CO), thoracic fluid index (TFI), heart rate (HR), and respiration rate (RR). CoVaTM-generated data were wirelessly analyzed to established markers of decompensation, defined as decline in systolic blood pressure of >20mmHg over 5 minutes or SpO2 values < 90%. Decompensation index (DI), a normalized index defined as: DI = mean{(norm d[HR]/dt) + (norm d[HRV]/dt) + (norm d[SV]/dt) + (norm d[RR]/dt) + (norm [TI]/dt)} was used to predict decompensation events.
Result(s): Patients continuously monitored for >8 hours with CoVaTM, who were also sporadically measured at least 5 times with the vital sign monitor (N=11) were analyzed. Agreement of the two parameters measured by both devices-HR and RR-was: DELTAHR = 6.5+/-0.3 bpm; DELTARR = 3.8+/-0.8 breaths/min. 55% of patients (N=6) experienced brief decompensation events. The vital sign monitor made sporadic measurements every 95+/-21.3 minutes. Using DI, CoVaTM predicted 78% of the total patient decompensations, with the average prediction being 22+/-23 minutes in advance.
Conclusion(s): Continuous measurements with a wearable device may detect post-procedure decompensation in patients receiving electrophysiology procedures or device implantations with greater accuracy and better temporal resolution as compared to sporadic measurements with conventional vital sign monitors.
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Background: Implantable loop recorder (ILR) based monitoring of patients with LQTS allows enhanced arrhythmia surveillance and can help distinguish life-threatening from benign arrhythmias.
Objective(s): We present a case of a child with LQTS and wide complex tachycardia detected by ILR.
Result(s): An asymptomatic 12 year old with LQT2 syndrome, positive for a G648S hERG mutation, with baseline QTc of 510-550ms despite maximally tolerated Nadolol (Figure 1A) was followed in our inherited arrhythmia center. His affected mother has had multiple syncopal events related to polymorphic ventricular tachycardia (VT) and appropriate ICD shocks. We elected to implant him with ILR to allow longitudinal monitoring and early detection of arrhythmia. He presented 6 months later with 2 alerts for asymptomatic polymorphic, wide complex tachycardia at ~200 bpm during sleeping (Figure 1B). Electrophysiology study (EPS) was performed to determine etiology of the arrhythmia. Dual AV node physiology was present. Sinus tachycardia at 200 bpm with left bundle branch block (LBBB) morphology was induced with Isoproterenol and atrio-fascicular pathway was excluded. Respiratory changes resulted in the tachycardia appearing as polymorphic on the ILR during the EPS.
Conclusion(s): This is the first reported case of sinus tachycardia with LBBB aberrancy in a child with LQTS. Pseudopolymorphic wide complex tachycardia was the result of aberrancy and respiratory artifact. Combined ILR monitoring and EP study provided a correct diagnosis, thus avoiding further interventions. [Figure presented]
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Background: Left ventricular outflow tract (LVOT) obstruction is associated with adverse outcomes in hypertrophic cardiomyopathy (HCM). AV sequential pacing has not demonstrated benefit for patients with medication-refractory LVOT obstruction in prospective, randomized clinical trials, although these trials did not include transthoracic echocardiogram (TTE) guided optimization or concomitant pharmacotherapy with disopyramide.
Objective(s): To evaluate efficacy of a standardized TTE guided AV optimization protocol for patients with persistent LVOT obstruction despite AV sequential pacing for reduction in LVOT gradient.
Method(s): Outcomes of 20 consecutive HCM patients with medication refractory LVOT gradients who were not surgical candidates and underwent AV sequential pacing from 8/2014 to 6/2017 were analyzed. ECG guided AV intervals were determined by the implanting cardiac electrophysiologist at the time of implant. Patients with incomplete response to initial settings underwent Doppler TTE guided AV optimization.
Result(s): All patients received maximally tolerated disopyramide and beta or calcium channel blockade. Following initial implant, 8 of 20 (40%) of patients had complete elimination of LVOT gradient with, and 12 of 20 (60%) had incomplete response and underwent TTE guided optimization. Compared to initial ECG guided programming, the TTE optimized sensed AV delays were shorter in all patients (mean reduction 51 +/- 48ms). Following TTE guided AV optimization, 9 of 12 patients had elimination of LVOT gradient, and 3 of 12 patients had 82.6 +/- 5.2% reduction in LVOT gradient. Patients undergoing TTE optimization had significant reduction in NYHA heart failure class (1.0 +/- 0 vs. 2.2 +/- 0.7, p=0.004).
Conclusion(s): TTE guided AV optimization shows promise as a means of improving outcomes in patients with incomplete response to medical therapy including disopyramide and AV sequential pacing for reduction of LVOT gradient in HCM.
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Background: Increased catheter stability during AF ablation is associated with higher ablation success rates. Rapid cardiac pacing and high frequency jet ventilation (HFJV) have both been independently shown to improve catheter stability. Simultaneous modulation of cardiac and respiratory motion has not been previously studied.
Objective(s): To study the effects of modulating heart rate and respiratory rate simultaneously on catheter stability.
Method(s): Forty paroxysmal AF patients were randomized to four study conditions. Ablation lesions were created at 15 prespecified locations. Twenty patients received atrial pacing (500 msec) during the first half of each lesion; twenty patients were paced during the second half of each lesion. Within each group, half received HFJV and half received standard ventilation. Contact force (CF) variability, defined as CF standard deviation, was compared between study groups.
Result(s): Compared to sinus rhythm and standard ventilation, rapid pacing (5.45 g vs. 5.86 g; p=0.006) and HFJV (5.10 g; p=0.003) each significantly reduced mean CF standard deviation. Simultaneous pacing and HFJV produced even greater reduction of mean CF standard deviation (4.29 g; p<0.001) (Figure). Pacing and HFJV alone had similar effects on mean CF variability (p=0.2).
Conclusion(s): Rapid pacing and HFJV synergistically improve catheter stability during AF ablation. Simultaneous pacing with HFJV further optimizes catheter stability over pacing or HFJV alone and may improve ablation outcomes. [Figure presented]
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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.