Faculty Bibliography

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.

AIMS/OBJECTIVE: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/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/CONCLUSIONS: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.

INTRODUCTION/BACKGROUND:A common complication of 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 RBBB was more frequent in device-dependent patients (19 of 38, 50% vs 4 of 22, 18%; RR 2.75; p = 0.01). Device-dependence was associated with AVBIII as the first post-procedural rhythm (37 of 39, 95% vs 12 of 22, 55%; RR 1.74; p<0.0001), earlier implantation (median 1d, IQR: 0-1.5d vs 2d, IQR: 1.0-4.0d, p = 0.0004), and a shorter duration of hospitalization (median 3d, IQR: 2-3.5d vs 4d, IQR: 2-5.75d, p = 0.03). Pacemaker dependence was also associated with a higher prosthesis-to-LVOT diameter (1.45±0.11 vs 1.39±0.07; p = 0.02) and the lack of prior aortic valvuloplasty (5 of 39, 13% vs 8 of 22, 36%; RR 0.35; p = 0.03). 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. This article is protected by copyright. All rights reserved.

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.

PURPOSE OF REVIEW/OBJECTIVE: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/RESULTS: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.

Background: Despite the increased prevalence of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM), the efficacy of radiofrequency ablation (RFA) has been characterized over limited follow-up intervals (~1 year). Several large meta-analyses note that patients with HCM have substantially higher rates of arrhythmia recurrence after RFA, compared to patients without HCM. The implication of confirmed HCM mutations on ablation efficacy has similarly only been assessed in small-scale studies.
Objective(s): To assess arrhythmia recurrence after RFA in patients with HCM and paroxysmal AF (PAAF) or persistent AF (PEAF) as well as its relation to their genetic background and LVOT gradient.
Method(s): Arrhythmia recurrence after RFA was assessed in 66 HCM patients and compared to 343 patients without HCM. AF recurrence was defined as AF on EKG or >30s of AF on ICD/pacemaker interrogation or on monitoring devices after a 3-month blanking period. Kaplan-Meier analysis was performed to compare arrhythmia recurrence rate and timing.
Result(s): The EF of HCM patients was higher than that of the non-HCM patients in both the PAAF and PEAF groups (65.5 and 63.0% vs 61.4 and 53.3%, respectively, p<0.001); within the HCM group, the clinical characteristics of the genetically (+) HCM group (n=14) did not differ from those of the genetically (-) group (n=12). Arrhythmia recurrence at 1 year in PAAF and PEAF was not significantly different between HCM and non-HCM patients (18% vs 11%, p=0.2, and 33% vs 26%, p=1), nor was mean time to arrhythmia recurrence (PAAF 193+/-48 vs 181+/-59 days, p=0.8, and PEAF 175+/-58 vs 168+/-20 days, p=0.6). Recurrence rates over the entire follow-up period of the HCM patients were 54 and 85% in the PAAF and PEAF groups (1076+/-187 and 1050+/- 201 days of follow-up), respectively. Amongst HCM patients with LVOT gradients >70mmHg (PAAF, n = 8, and PEAF, n = 3) longer-term rates of arrhythmia recurrence were similar at 88% and 67% (p=0.9).
Conclusion(s): Arrhythmia recurrence at 1 year following AF ablation in HCM patients is similar to that of non-HCM AF patients regardless of the type of AF. Absolute rates of atrial arrhythmia recurrence in HCM patients at >3 years post ablation are considerable. Confirmed HCM mutations and severe LVOT gradients do not modify the outcome of AF ablation.
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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: 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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