Catheter ablation of atrioventricular nodal reentrant tachycardia with an irrigated contact-force sensing radiofrequency ablation catheter.

INTRODUCTION: Radiofrequency ablation (RFA) slow pathway modification for catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) is traditionally performed using a 4-mm nonirrigated (NI) RF ablation catheter. Slow pathway modification using irrigated, contact-force sensing (ICFS) RFA catheters has been described in case reports, but the outcomes have not been systematically evaluated. METHODS: Acute procedural outcomes of 200 consecutive patients undergoing slow pathway modification for AVNRT were analyzed. A 3.5-mm ICFS RFA catheter (ThermoCool SmartTouch STSF, Biosense Webster, Inc.) was utilized in 134 patients, and a 4-mm NI RFA catheter (EZ Steer, Biosense Webster, Inc.) was utilized in 66 patients. Electroanatomic maps were retrospectively analyzed in a blinded fashion to determine the proximity of ablation lesions to the His region. RESULTS: The baseline characteristics of patients in both groups were similar. Total RF time was significantly lower in the ICFS group compared to the NI group (5.53 ± 4.6 vs. 6.24 ± 4.9 min, p = 0.03). Median procedure time was similar in both groups (ICFS, 108.0 (87.5-131.5) min vs. NI, 100.0 (85.0-125.0) min; p = 0.2). Ablation was required in closer proximity to the His region in the NI group compared to the ICFS group (14.4 ± 5.9 vs. 16.7 ± 6.4 mm, respectively, p = 0.01). AVNRT was rendered noninducible in all patients, and there was no arrhythmia recurrence during follow-up in both groups. Catheter ablation was complicated by AV block in one patient in the NI group. CONCLUSION: Slow pathway modification for catheter ablation of AVNRT using an ICFS RFA catheter is feasible, safe, and may facilitate shorter duration ablation while avoiding ablation in close proximity to the His region.

Temporal trends in atrial fibrillation ablation procedures at an academic medical center: 2011-2021.

INTRODUCTION: Radiofrequency ablation technology for treating atrial fibrillation (AF) has evolved rapidly over the past decade. We investigated the impact of technological and procedural advances on procedure times and ablation outcomes at a major academic medical center over a 10-year period. METHODS: Clinical data was collected from patients who presented to NYU Langone Health between 2011 and 2021 for a first-time AF ablation. Time to redo AF ablation or direct current cardioversion (DCCV) for recurrent AF during a 3-year follow-up period was determined and correlated with ablation technology and practices, antiarrhythmic medications, and patient comorbid conditions. RESULTS: From 2011 to 2021, the cardiac electrophysiology lab adopted irrigated-contact force ablation catheters, high-power short duration ablation lesions, steady-pacing, jet ventilation, and eliminated stepwise linear ablation for AF ablation. During this time the number of first time AF ablations increased from 403 to 1074, the percentage of patients requiring repeat AF-related intervention within 3-years of the index procedure dropped from 22% to 14%, mean procedure time decreased from 271 ± 65 to 135 ± 36 min, and mean annual major adverse event rate remained constant at 1.1 ± 0.5%. Patient comorbid conditions increased during this time period and antiarrhythmic use was unchanged. CONCLUSION: Rates of redo-AF ablation or DCCV following an initial AF ablation at a single center decreased 36% over a 10-year period. Procedural and technological changes likely contributed to this improvement, despite increased AF related comorbidities.

Outcomes and atrial substrate analysis in patients with HIV undergoing atrial fibrillation ablation.

INTRODUCTION: Patients with HIV infection have increased risk of atrial fibrillation, but the pathophysiologic mechanisms and the utility of catheter ablation in this population are not well-studied. We aimed to characterize outcomes of atrial fibrillation ablation and left atrial substrate in patients with HIV. METHODS: The study was a retrospective propensity score-matched analysis of patients with and without HIV undergoing atrial fibrillation ablation. A search was performed in the electronic medical record for all patients with HIV who received initial atrial fibrillation ablation from 2011 to 2020. After calculating propensity scores for HIV, matching was performed with patients without HIV by using nearest-neighbor matching without replacement in a 1:2 ratio. The primary outcome was freedom from atrial arrhythmia and secondary outcomes were freedom from atrial fibrillation, freedom from atrial tachycardia, and freedom from repeat ablation, compared by log-rank analysis. The procedures of patients with HIV who underwent repeat ablation at our institution were further analyzed for etiology of recurrence. To further characterize the left atrial substrate, a subsequent case-control analysis was then performed for a set of randomly chosen 10 patients with HIV matched with 10 without HIV to compare minimum and maximum voltage at nine pre-specified regions of the left atrium. RESULTS: Twenty-seven patients with HIV were identified. All were prescribed antiretroviral therapy at time of ablation. These patients were matched with 54 patients without HIV by propensity score. 86.4% of patients with HIV and 76.9% of controls were free of atrial fibrillation or atrial tachycardia at 1 year (p = .509). Log-rank analysis showed no difference in freedom from atrial arrhythmia (p value .971), atrial fibrillation (p-value .346), atrial tachycardia (p value .306), or repeat ablation (p value .401) after initial atrial fibrillation ablation in patients with HIV compared to patients without HIV. In patients with HIV with recurrent atrial fibrillation, the majority had pulmonary vein reconnection (67%). There were no significant differences in minimum or maximum voltage at any of the nine left atrial regions between the matched patients with and without HIV. CONCLUSIONS: Ablation to treat atrial fibrillation in patients with HIV, but without overt AIDS is frequently successful therapy. The majority of patients with recurrence of atrial fibrillation had pulmonary vein reconnection, suggesting infrequent nonpulmonary vein substrate. In this population, the left atrial voltage in patients with HIV is similar to that of patients without HIV. These findings suggest that the pulmonary veins remain a critical component to the initiation and maintenance of atrial fibrillation in patients with HIV.

Correlation between AV synchrony and device collected AM-VP sequence counter in atrioventricular synchronous leadless pacemakers: A real-world assessment.

INTRODUCTION: Micra atrioventricular (AV) provides leadless atrioventricular synchronous pacing by sensing atrial contraction (A4 signal). Real-world operation and reliability of AV synchrony (AVS) assessment using device data have not been described. The purposes of this study were to (1) assess the correlation between AVS and atrial mechanical sensed-ventricular pacing (AM-VP) percentages in patients with permanent high-degree AV block and (2) report on the real-world effectiveness of Micra AV. METHODS: The correlation between ECG-determined AVS in-clinic and device-collected %AM-VP was assessed using data from 40 patients with high-degree AV block enrolled in the Micra Atrial tRacking using a Ventricular AccELerometer (MARVEL) 2 study. A retrospective analysis to assess continuously-sampled %AM-VP since last session, device programming, and electrical parameters was performed using Micra AV transmissions from the Medtronic CareLink database. Patients with transmissions ≥180 days postimplant were included. RESULTS: Among the 40 MARVEL 2 AV block patients with a median %VP of 99.7%, AVS was highly correlated with AM-VP (median AVS 87.1%, median AM-VP 79.1%; R2 = 0.764, p < .001). The CareLink cohort included 4384 patients programmed to VDD mode. The mean A4 amplitude was 2.3 ± 1.8 m/s2 at implant and 2.3 ± 1.6 m/s2 at 28 weeks. In patients with %VP >90% (n = 1662), the median %AM-VP was 74.7%. For the full cohort, median %VP was 65.6% and median projected battery longevity was 10.5 years. CONCLUSION: In patients with a high pacing burden, %AM-VP provides a reasonable estimation of AVS. The first large real-world analysis of Micra AV patients with >90% VP showed stable atrial sensing over time with a median %AM-VP, a correlate of AVS, of 74.7%.

Outcomes of posterior wall isolation with pulmonary vein isolation for paroxysmal atrial fibrillation.

INTRODUCTION: Prior studies have shown that addition of posterior wall isolation (PWI) may reduce atrial fibrillation recurrence in patients with persistent atrial fibrillation. No data on PWI in paroxysmal AF (pAF) patients with normal left atrial voltage is available, to date. OBJECTIVE: This study sought to evaluate the efficacy of PWI in addition to pulmonary vein isolation (PVI) in patients presenting with pAF and normal left atrial voltage. METHODS: Consecutive patient registry analysis was performed on all patients with pAF and normal left atrial voltage undergoing initial radiofrequency ablation from November 1, 2018 to November 15, 2019. Primary endpoint was recurrence of atrial arrhythmia including AF, atrial tachycardia (AT), or atrial flutter (AFL). RESULTS: A total of 321 patients were studied, 214 in the PVI group and 107 in the PWI + PVI group. Recurrence of any atrial arrhythmia occurred in 18.2% of patients in the PVI group and 16.8% in the PVI + PWI cohort (p = 0.58). At 1 year, recurrence was 14.0% in the PVI group and 15.0% in the PWI + PVI group (p = 0.96). There was a lower AT/AFL recurrence in the PVI + PWI group, not reaching significance (3.7% in the PWI + PVI group vs. 7.9% in PVI group, p = 0.31). Need for carina lesions predicted recurrence in the PVI-only group. CONCLUSIONS: Addition of PWI to PVI in pAF patients undergoing their first ablation did not reduce the frequency of atrial arrhythmia recurrence. This warrants further study in a prospective trial.

Development and validation of a risk score for predicting pericardial effusion in patients undergoing leadless pacemaker implantation: experience with the Micra transcatheter pacemaker.

AIMS: There is limited information on what clinical factors are associated with the development of pericardial effusion after leadless pacemaker implantation. We sought to determine predictors of and to develop a risk score for pericardial effusion in patients undergoing Micra leadless pacemaker implantation attempt. METHODS AND RESULTS: Patients (n = 2817) undergoing implant attempt from the Micra global trials were analysed. Characteristics were compared between patients with and without pericardial effusion (including cardiac perforation and tamponade). A risk score for pericardial effusion was developed from 18 pre-procedural clinical variables using lasso logistic regression. Internal validation and future prediction performance were estimated using bootstrap resampling. The scoring system was also externally validated using data from the Micra Acute Performance European and Middle East (MAP EMEA) registry. There were 32 patients with a pericardial effusion [1.1%, 95% confidence interval (CI): 0.8-1.6%]. Following lasso logistic regression, 11 of 18 variables remained in the model from which point values were assigned. The C-index was 0.79 (95% CI: 0.71-0.88). Patient risk score profile ranged from -4 (lowest risk) to 5 (highest risk) with 71.8% patients considered low risk (risk score ≤0), 16.6% considered medium risk (risk score = 1), and 11.7% considered high risk (risk score ≥2) for effusion. The median C-index following bootstrap validation was 0.73 (interquartile range: 0.70-0.75). The C-index based on 9 pericardial effusions from the 928 patients in the MAP EMEA registry was 0.68 (95% CI: 0.52-0.83). The pericardial effusion rate increased significantly with additional Micra deployments in medium-risk (P = 0.034) and high-risk (P < 0.001) patients. CONCLUSION: The overall rate of pericardial effusion following Micra implantation attempt is 1.1% and has decreased over time. The risk of pericardial effusion after Micra implant attempt can be predicted using pre-procedural clinical characteristics with reasonable discrimination. CLINICAL TRIAL REGISTRATION: The Micra Post-Approval Registry (ClinicalTrials.gov identifier: NCT02536118), Micra Continued Access Study (ClinicalTrials.gov identifier: NCT02488681), and Micra Transcatheter Pacing Study (ClinicalTrials.gov identifier: NCT02004873).

Behavior of AV synchrony pacing mode in a leadless pacemaker during variable AV conduction and arrhythmias.

INTRODUCTION: MARVEL 2 assessed the efficacy of mechanical atrial sensing by a ventricular leadless pacemaker, enabling a VDD pacing mode. The behavior of the enhanced MARVEL 2 algorithm during variable atrio-ventricular conduction (AVC) and/or arrhythmias has not been characterized and is the focus of this study. METHODS: Of the 75 patients enrolled in the MARVEL 2 study, 73 had a rhythm assessment and were included in the analysis. The enhanced MARVEL 2 algorithm included a mode-switching algorithm that automatically switches between VDD and ventricular only antibradycardia pacing (VVI)-40 depending upon AVC status. RESULTS: Forty-two patients (58%) had persistent third degree AV block (AVB), 18 (25%) had 1:1 AVC, 5 (7%) had variable AVC status, and 8 (11%) had atrial arrhythmias. Among the 42 patients with persistent third degree AVB, the median ventricular pacing (VP) percentage was 99.9% compared to 0.2% among those with 1:1 AVC. As AVC status changed, the algorithm switched to VDD when the ventricular rate dropped less than 40 bpm. During atrial fibrillation (AF) with ventricular response greater than 40 bpm, VVI-40 mode was maintained. No pauses longer than 1500 ms were observed. Frequent ventricular premature beats reduced the percentage of AV synchrony. During AF, the atrial signal was of low amplitude and there was infrequent sensing. CONCLUSION: The mode switching algorithm reduced VP in patients with 1:1 AVC and appropriately switched to VDD during AV block. No pacing safety issues were observed during arrhythmias.

Quantitative analysis of ablation technique predicts arrhythmia recurrence following atrial fibrillation ablation.

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.

Early ICD lead failure in defibrillator systems with multiple leads via cephalic access.

INTRODUCTION: 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 to 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 = .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 < .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: 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.

Direct autotransfusion following emergency pericardiocentesis in patients undergoing cardiac electrophysiology procedures.

INTRODUCTION: 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 3-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). The 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 = .52). Amongst patients with aspirated volumes <1 L, group 1 patients (n = 4) were less likely than group 2 patients (n = 8) to require allotransfusion (0% vs 75%, P = .02). Amongst patients with aspirated volume ≥1 L, group 1 patients (n = 6) required fewer units of red cell allotransfusion than group 2 patients (n = 6) (1.5 ± 0.8 units vs 4.3 ± 2.0 units, P = .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. The utilization of direct autotransfusion may eliminate or reduce the need for allotransfusion.

Multiple procedure outcomes for nonparoxysmal atrial fibrillation: Left atrial posterior wall isolation versus stepwise ablation.

OBJECTIVE: To compare multiple-procedure catheter ablation outcomes of a stepwise approach versus left atrial posterior wall isolation (LA PWI) in patients undergoing nonparoxysmal atrial fibrillation (NPAF) ablation. BACKGROUND: Unfavorable outcomes for stepwise ablation of NPAF in large clinical trials may be attributable to proarrhythmic effects of incomplete ablation lines. It is unknown if a more extensive initial ablation strategy results in improved outcomes following multiple ablation procedures. METHODS: Two hundred twenty two consecutive patients with NPAF underwent first-time ablation using a contact-force sensing ablation catheter utilizing either a stepwise (Group 1, n = 111) or LA PWI (Group 2, n = 111) approach. The duration of follow-up was 36 months. The primary endpoint was freedom from atrial arrhythmia >30 s. Secondary endpoints were freedom from persistent arrhythmia, repeat ablation, and recurrent arrhythmia after repeat ablation. RESULTS: There was similar freedom from atrial arrhythmias after index ablation for both stepwise and LA PWI groups at 36 months (60% vs. 69%, p = .1). The stepwise group was more likely to present with persistent recurrent arrhythmia (29% vs. 14%, p = .005) and more likely to undergo second catheter ablation (32% vs. 12%, p < .001) compared to LA PWI patients. Recurrent arrhythmia after repeat ablation was more likely in the stepwise group compared to the LA PWI group (15% vs. 4%, p = .003). CONCLUSIONS: Compared to a stepwise approach, LA PWI for patients with NPAF resulted in a similar incidence of any atrial arrhythmia, lower incidence of persistent arrhythmia, and fewer repeat ablations. Results for repeat ablation were not improved with a more extensive initial approach.

Rapid pacing and high-frequency jet ventilation additively improve catheter stability during atrial fibrillation ablation.

INTRODUCTION: 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 prespecified 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 the patients received HFJV and the other 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 ± 3.08 g), compared to lesions with pacing and standard ventilation (5.45 ± 3.28 g; P < .01) or to lesions with no pacing and HFJV (4.92 ± 3.00 g; P < .01). Lesions with both pacing and HFJV had the greatest reduction in contact force standard deviation (4.35 ± 2.81 g; P < .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 < .001). DISCUSSION: 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.

Reducing right ventricular pacing burden: algorithms, benefits, and risks.

Algorithms designed to reduce the burden of right ventricular pacing are widely available in modern implantable pacing devices. To ensure safe and optimal utilization, understanding the properties of these algorithms as well as their possible unfavourable effects is essential. In this review, we discuss in detail the technical and clinical aspects of rhythm management algorithms and update on their significant recent modifications. In addition, we highlight possible adverse phenomena that may be induced by these different pacing algorithms intended to minimize pacing.

Patient selection, pacing indications, and subsequent outcomes with de novo leadless single-chamber VVI pacing.

AIMS: Patient selection is a key component of securing optimal patient outcomes with leadless pacing. We sought to describe and compare patient characteristics and outcomes of Micra patients with and without a primary pacing indication associated with atrial fibrillation (AF) in the Micra IDE trial. METHODS AND RESULTS: The primary outcome (risk of cardiac failure, pacemaker syndrome, or syncope related to the Micra system or procedure) was compared between successfully implanted patients from the Micra IDE trial with a primary pacing indication associated with AF or history of AF (AF group) and those without (non-AF group). Among 720 patients successfully implanted with Micra, 228 (31.7%) were in the non-AF group. Reasons for selecting VVI pacing in non-AF patients included an expectation for infrequent pacing (66.2%) and advanced age (27.2%). More patients in the non-AF group had a condition that precluded the use of a transvenous pacemaker (9.6% vs. 4.7%, P = 0.013). Atrial fibrillation patients programmed to VVI received significantly more ventricular pacing compared to non-AF patients (median 67.8% vs. 12.6%; P < 0.001). The overall occurrence of the composite outcome at 24 months was 1.8% with no difference between the AF and non-AF groups (hazard ratio 1.36, 95% confidence interval 0.45-4.2; P = 0.59). CONCLUSION: Nearly one-third of patients selected to receive Micra VVI therapy were for indications not associated with AF. Non-AF VVI patients required less frequent pacing compared to patients with AF. Risks associated with VVI therapy were low and did not differ in those with and without AF.

Behavior of leadless AV synchronous pacing during atrial arrhythmias and stability of the atrial signals over time-Results of the MARVEL Evolve subanalysis.

INTRODUCTION: The MARVEL study demonstrated at a single time point that accelerometer (ACC)-based atrial sensing improves atrioventricular (AV) synchrony (AVS) in patients with AV block and a Micra pacemaker (Medtronic, Minneapolis, MN, USA). The purpose of the MARVEL Evolve substudy was to assess the performance over time. METHODS: This prospective single-center study compared AVS and ACC signals at two visits ≥6 months apart. Custom software was temporarily downloaded into the Micra at each visit and AVS was measured during 30 min at rest. RESULTS: Nine patients from the MARVEL study were enrolled. The mean (±standard deviation) age was 82.3 ± 6.0 years old, 67% were male, and a Micra was implanted for 6.0 ± 6.4 months. High-degree AV block was present in four patients, whereas five with predominantly intrinsic conduction required intermittent pacing for bradycardia. The mean interval between visits was 7.1 ± 0.6 months. Seven patients had normal sinus node function at both visits and were included in a paired analysis. Both ACC signal amplitude (visit 2-visit 1 = 1.4 mG; 95% confidence interval [CI] [-25.8 to 28.4 mG]; P = 0.933) and AVS (visit 1: 90.8%, 95% CI [72.4, 97.4] and visit 2: 91.4%, 95% CI [63.8, 98.5]; P = 0.740) remained stable. Three patients had spontaneous atrial tachycardia. During atrial fibrillation, no atrial contraction was detected or tracked. During atrial flutter, intermittent tracking resulted in a ventricular rate of 60 ± 8 beats per minute (bpm); there was no ventricular pacing >100 bpm. CONCLUSION: ACC signals amplitude and performance of AVS pacing were stable over time. During atrial arrhythmias, the AV synchronous pacing mode behaved safely.

Factors predicting persistence of AV nodal block in post-TAVR patients following permanent pacemaker implantation.

INTRODUCTION: A common complication of transcatheter aortic valve repair (TAVR) is development of conduction defects requiring pacemaker (PPM) implantation. These defects are not universally permanent. OBJECTIVE: To determine the incidence and predictors of persistent device dependency in patients with PPM implantation following TAVR with a self-expanding prosthesis. METHODS: Records of patients who underwent post-TAVR PPM implantation were reviewed. Patients with persistent complete AV block (AVBIII) one month post-TAVR were compared to those regaining conduction. RESULTS: Between September 2014 and March 2017, 485 patients underwent TAVR with a self-expanding prosthesis; 77 (15.9%) underwent PPM implantation for AVBIII. Device interrogation at one month was available for 61 patients (79%): 22 (36.1%) had resolution of AVBIII while 39 (63.9%) remained pacemaker-dependent. Pre-TAVR right bundle branch block was more frequent in device-dependent patients (19 of 38, 50% vs 4 of 22, 18%; RR 2.75; P = .01). Device-dependence was associated with AVBIII as the first postprocedural rhythm (37 of 39, 95% vs 12 of 22, 55%; RR 1.74; P < .0001), earlier implantation (median 1d, IQR: 0-1.5d vs 2d, IQR: 1.0-4.0d, P = .0004), and a shorter duration of hospitalization (median 3d, IQR: 2-3.5d vs 4d, IQR: 2-5.75d, P = .03). Pacemaker dependence was also associated with a higher prosthesis-to left ventricular outflow tract (LVOT) diameter (1.45 ± 0.11 vs 1.39 ± 0.07; P = .02) and the lack of prior aortic valvuloplasty (5 of 39, 13% vs 8 of 22, 36%; RR 0.35; P = .03). CONCLUSIONS: In patients receiving a PPM following self-expanding TAVR, a long-term pacing requirement can be predicted from the timing of AV block, existing conduction-system disease, larger prosthesis-to-LVOT diameter, and the lack of aortic valvuloplasty.

Photorealistic imaging of left atrial appendage occlusion/exclusion.

Recent improvements in 3D TEE post processing rendering techniques referred to as TrueVue (Philips Medical Systems, Andover, MA, USA). It allows for novel photorealistic imaging of cardiac structures including left atrial appendage (LAA) and its closure devices. Here we present TrueVue images of the LAA prior to and after LAA exclusion/occlusion using various percutaneous and surgical techniques. TrueVue may improve delineation of LAA anatomy prior to occlusion as well as visualization of occluder device position within the LAA.

Left Atrial Occlusion Device Implantation: the Role of the Echocardiographer.

PURPOSE OF REVIEW: Atrial fibrillation is the most common arrhythmia worldwide and is a major risk factor for embolic stroke. For patients with atrial fibrillation who are unable to tolerate systemic anticoagulation, left atrial appendage (LAA) occlusion has been shown to mitigate stroke risk. In this article, we describe the vital role of the echocardiographer in intraprocedural guidance of percutaneous LAA occlusion procedures as well as in the pre- and post-procedure assessment of these patients. RECENT FINDINGS: A few percutaneously delivered devices for LAA exclusion from the systemic circulation are available in contemporary practice. These devices employ an either exclusive endocardial LAA occlusion approach, such as the Watchman (Boston Scientific, Maple Grove, MN) and Amulet (St. Jude Medical, Minneapolis, MN), or both an endocardial and pericardial (epicardial) approach such as the Lariat procedure (SentreHEART, Palo Alto, CA). Two- and three-dimension transesophageal echocardiography is critical for patient selection, procedure planning, procedural guidance, and ensuring satisfactory immediate as well as long-term LAA occlusion/exclusion efficacy. This review will provide an overview of the role of the echocardiographer in all aspects of LAA occlusion/exclusion procedures for the most commonly used commercially available devices in current practice.

Safety and efficiency of porous-tip contact-force catheter for drug-refractory symptomatic paroxysmal atrial fibrillation ablation: results from the SMART SF trial.

Aims: THERMOCOOL SMARTTOUCH® SF Catheter is a new contact-force (CF)-sensing catheter with 56-hole porous tip designed for improved cooling and reduced fluid delivery compared with a standard 6-hole open-irrigated catheter. The SMART SF study examined the periprocedural safety, acute effectiveness, and procedural efficiency of the catheter for drug-refractory symptomatic paroxysmal atrial fibrillation (PAF) ablation. Methods and results: The prospective, open-label, non-randomized SMART-SF was conducted at 17 US sites. Circumferential pulmonary vein (PV) isolation was performed with confirmation of entrance block in all PVs. Stable ablation sites were identified using CARTO VISITAG™ Module. Primary adverse events (AEs; ≤1 week of index procedure), periprocedural AEs within 30 days of ablation procedure, acute effectiveness (confirmation of entrance block for targeted PVs), CF, and procedural parameters were assessed. Overall, 165 patients were enrolled (mean age, 62.7 years; male, 57.9%; white, 97%; left ventricular ejection fraction, 60.1 ± 7%; left atrium diameter, 38.8 ± 6 mm); 159 underwent radiofrequency ablation and comprised the safety cohort. Primary safety performance criteria were met: primary AE rate was 2.5% (4/159; cardiac tamponade [n = 2], thrombo-embolism [n = 1], transient ischaemic attack [n = 1]). All primary AEs resolved/improved within the 1-month follow-up period. Acute procedural effectiveness was attained in 96.2% (95% confidence interval: 92.0-98.6%) of patients. Procedure time, fluoroscopy time, and fluid delivered were observed in comparison to predecessor catheters. Conclusion: In the SMART-SF trial, the predetermined safety performance goal was met, demonstrating the safety and acute effectiveness of the THERMOCOOL SMARTTOUCH® SF Catheter for PAF ablation.