A Modular Communicative Leadless Pacing-Defibrillator System.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

Design and Rationale of a Pragmatic Randomized Clinical Trial of Early Dronedarone versus Usual Care to Change and Improve Outcomes in Persons with First-Detected Atrial Fibrillation - The CHANGE AFIB Study.

BACKGROUND: While there are several completed clinical trials that address treatment strategies in patients with symptomatic and recurrent atrial fibrillation (AF), there are no randomized clinical trials that address first-line rhythm control of new-onset AF. Recent data suggest that early initiation of rhythm control within 1 year can improve outcomes. METHODS: In this open-label pragmatic clinical trial nested within the Get With The Guidelines Atrial Fibrillation registry, approximately 3,000 patients with first-detected AF will be enrolled at approximately 200 sites. Participants will be randomized (1:1) to treatment with dronedarone in addition to usual care versus usual care alone. The primary endpoint will be time to first cardiovascular (CV) hospitalization or death from any cause through 12 months from randomization. Secondary endpoints will include a WIN ratio (all-cause death, ischemic stroke or systemic embolism, heart failure hospitalization, acute coronary hospitalization), CV hospitalization, and all-cause mortality. Patient reported outcomes will be analyzed based on change in Atrial Fibrillation Effect on Quality of Life (AFEQT) and change in Mayo AF-Specific Symptom Inventory (MAFSI) from baseline to 12 months. CONCLUSION: CHANGE AFIB will determine if treatment with dronedarone in addition to usual care is superior to usual care alone for the prevention of CV hospitalization or death from any cause in patients with first-detected AF. The trial will also determine whether initiation of rhythm control at the time of first-detected AF affects CV events or improves patient reported outcomes. CLINICALTRIALS: GOV #: - NCT05130268.

Utility of noninvasive electrocardiographic imaging in the localization of nonpulmonary vein triggers of atrial fibrillation determined by pacing common trigger sites.

INTRODUCTION: Identifying the origin of nonpulmonary vein atrial fibrillation (AF) triggers (NPVTs) after pulmonary vein isolation (PVI) can be challenging. We aimed to determine if noninvasive electrocardiographic imaging (ECGi) could localize pacing from common NPVT sites. ECGi combines measured body surface potentials with heart-torso geometry acquired from computed tomography (CT) to generate an activation map. METHODS: In 12 patients with AF undergoing first time ablation, the ECGi vest was fitted for preprocedural CT scan and worn during the procedure. After PVI, we performed steady-state pacing from 15 typical anatomic NPVT sites at a cycle length of 700-800 ms. We co-registered the invasive anatomic map with the CT-based ECGi epicardial activation map to compare ECGi predicted to true pacing origin. RESULTS: In the study cohort (67% male, 58% persistent AF, and 67% with left atrial dilation), 148 (82%) pacing sites had both capture and adequate anatomy acquired from the three-dimensional mapping system to co-register with ECGi activation map. Median distance between true pacing sites and point of earliest epicardial activation derived from the ECGi maps for all sites was 17 mm (interquartile range, 10-22 mm). Assuming paced sites treated as regions with a radius of 2.5 cm, the earliest activation site on ECGi map falls within the region with 94% accuracy. CONCLUSION: ECGi can approximate the origin of paced beats from common NPVT sites to within a median distance of 17 mm. A rapidly identified region may then be the focus of more detailed catheter-based mapping techniques to facilitate successful localization and ablation of NPVTs.

Prevalence of frequent premature ventricular contractions and left-ventricular systolic dysfunction in patients receiving Holter monitoring.

BACKGROUND: Premature ventricular contractions (PVCs) are frequently observed with left ventricular (LV) systolic dysfunction, although the prevalence of these associated conditions in the general population remains unknown. OBJECTIVE: We sought to understand the prevalence of frequent PVCs (defined PVCs > 5%) and high burden PVCs (defined PVCs > 10%) and LV systolic dysfunction in patients receiving ambulatory Holter monitors (HM). METHODS: A prospective multicenter (eight US medical centers) cross-sectional study collected demographic and PVC burden data from consecutive patients undergoing 24-h, 48-h, and 14-day HM (July 2018-June 2020). Left ventricle ejection fraction (LVEF) data was collected if obtained within 6 months of HM. Four PVC burden groups were analyzed (<1%, 1%-5%, 5.1%-10%, and >10% burden) and stratified by normal LVEF (≥50%) or presence LVEF < 50%. RESULTS: The prevalence of PVC burden of 5.1%-10% and >10% was 4% and 5%, respectively in the population undergoing HM (n = 6529). Age was significantly different between PVC groups (p < .001). In those with LVEF assessment (n = 3713), the prevalence of LVEF < 50% and both LVEF < 50% and PVC > 5% was 16.4% and 4.2%, respectively. The prevalence of PVC > 5% and PVC > 10% in patients with LVEF < 50% was 26% and 16%, respectively. PVC > 5% were more prevalent in older, male, and Caucasians (p < .001). Females had a lower prevalence of PVC > 5% than males (6% vs. 11%; p < .001), but not among those with LVEF < 50% (24% vs. 26%, p = .10). CONCLUSION: PVC > 5% and PVC > 10% and LVEF < 50% are prevalent in patients undergoing HM. PVC > 5% are associated with older age. Females have a lower prevalence of PVC > 5% than males but similar combined PVC > 5% and LVEF < 50%. CLINICALTRIAL: gov identifier: NCT03228823.

Multicenter experience with andexanet alfa for refractory pericardial bleeding during catheter ablation of atrial fibrillation.

INTRODUCTION: Pericardial bleeding is a rare but life-threatening complication of atrial fibrillation (AF) ablation. Patients taking uninterrupted oral anticoagulation (AC) may be at increased risk for refractory bleeding despite pericardiocentesis and administration of protamine. In such cases, andexanet alfa can be given to reverse rivaroxaban or apixaban. In this study, we aim to describe the rate of acute hemostasis and thromboembolic complications with andexanet for refractory pericardial bleeding during AF ablation. METHODS AND RESULTS: In this multicenter, case series, participating centers identified patients who received a dose of apixaban or rivaroxaban within 24 h of AF ablation, developed refractory pericardial bleeding during the procedure despite pericardiocentesis and administration of protamine and received andexanet. Eleven patients met inclusion criteria, with mean age of 73.5 ± 5.3 years and median CHA2 DS2 -VASc score 4 [3-5]. All patients received protamine and pericardiocentesis, and 9 (82%) received blood products. All patients received a bolus of andexanet followed, in all but one, by a 2-h infusion. Acute hemostasis was achieved in eight patients (73%) while three required emergent surgery. One patient (9%) experienced acute ST-elevation myocardial infarction after receiving andexanet. Therapeutic AC was restarted after a mean of 2.2 ± 1.9 days and oral AC was restarted after a mean of 2.9 ± 1.6 days, with no recurrent bleeding. CONCLUSION: In patients on uninterrupted apixaban or rivaroxaban, who develop refractory pericardial bleeding during AF ablation, andexanet can achieve hemostasis thereby avoiding the need for emergent surgery. However, there is a risk of thromboembolism following administration.

Persistent Opioid Use After Cardiac Implantable Electronic Device Procedures.

BACKGROUND: Prescription opioids are a major contributor to the ongoing epidemic of persistent opioid use (POU). The incidence of POU among opioid-naïve patients after cardiac implantable electronic device (CIED) procedures is unknown. METHODS: This retrospective cohort study used data from a national administrative claims database from 2004 to 2018 of patients undergoing CIED procedures. Adult patients were included if they were opioid-naïve during the 180-day period before the procedure and did not undergo another procedure with anesthesia in the next 180 days. POU was defined by filling an additional opioid prescription >30 days after the CIED procedure. RESULTS: Of the 143 400 patients who met the inclusion criteria, 15 316 (11%) filled an opioid prescription within 14 days of surgery. Among these patients, POU occurred in 1901 (12.4%) patients 30 to 180 days after surgery. The likelihood of developing POU was increased for patients who had a history of drug abuse (odds ratio, 1.52; P=0.005), preoperative muscle relaxant (odds ratio, 1.52; P<0.001) or benzodiazepine (odds ratio, 1.23; P=0.001) use, or opioid use in the previous 5 years (OR, 1.76; P<0.0001). POU did not differ after subcutaneous implantable cardioverter defibrillator or other CIED procedures (11.1 versus 12.4%; P=0.5). In a sensitivity analysis excluding high-risk patients who were discharged to a facility or who had a history of drug abuse or previous opioid, benzodiazepine, or muscle relaxant use, 8.9% of the remaining cohort had POU. Patients prescribed >135 mg of oral morphine equivalents had a significantly increased risk of POU. CONCLUSIONS: POU is common after CIED procedures, and 12% of patients continued to use opioids >30 days after surgery. Higher initially prescribed oral morphine equivalent doses were associated with developing POU.

Prognostic Value of Nonischemic Ringlike Left Ventricular Scar in Patients With Apparently Idiopathic Nonsustained Ventricular Arrhythmias.

BACKGROUND: Left ventricular (LV) scar on late gadolinium enhancement (LGE) cardiac magnetic resonance has been correlated with life-threatening arrhythmic events in patients with apparently idiopathic ventricular arrhythmias (VAs). We investigated the prognostic significance of a specific LV-LGE phenotype characterized by a ringlike pattern of fibrosis. METHODS: A total of 686 patients with apparently idiopathic nonsustained VA underwent contrast-enhanced cardiac magnetic resonance. A ringlike pattern of LV scar was defined as LV subepicardial/midmyocardial LGE involving at least 3 contiguous segments in the same short-axis slice. The end point of the study was time to the composite outcome of all-cause death, resuscitated cardiac arrest because of ventricular fibrillation or hemodynamically unstable ventricular tachycardia and appropriate implantable cardioverter defibrillator therapy. RESULTS: A total of 28 patients (4%) had a ringlike pattern of scar (group A), 78 (11%) had a non-ringlike pattern (group B), and 580 (85%) had normal cardiac magnetic resonance with no LGE (group C). Group A patients were younger compared with groups B and C (median age, 40 vs 52 vs 45 years; P<0.01), more frequently men (96% vs 82% vs 55%; P<0.01), with a higher prevalence of family history of sudden cardiac death or cardiomyopathy (39% vs 14% vs 6%; P<0.01) and more frequent history of unexplained syncope (18% vs 9% vs 3%; P<0.01). All patients in group A showed VA with a right bundle-branch block morphology versus 69% in group B and 21% in group C (P<0.01). Multifocal VAs were observed in 46% of group A patients compared with 26% of group B and 4% of group C (P<0.01). After a median follow-up of 61 months (range, 34-84 months), the composite outcome occurred in 14 patients (50.0%) in group A versus 15 (19.0%) in group B and 2 (0.3%) in group C (P<0.01). After multivariable adjustment, the presence of LGE with ringlike pattern remained independently associated with increased risk of the composite end point (hazard ratio, 68.98 [95% CI, 14.67-324.39], P<0.01). CONCLUSIONS: In patients with apparently idiopathic nonsustained VA, nonischemic LV scar with a ringlike pattern is associated with malignant arrhythmic events.

Oral anticoagulant use in patients with atrial fibrillation and mitral valve repair.

BACKGROUND: Patients with atrial fibrillation (AF) who have undergone mitral valve repair are at risk for thromboembolic strokes. Prior to 2019, only vitamin K antagonists were recommended for patients with AF who had undergone mitral valve repair despite the introduction of direct oral anticoagulants (DOAC) in 2010. OBJECTIVE: To characterize the use of anticoagulants in patients with AF who underwent surgical mitral valve repair (sMVR) or transcatheter mitral valve repair (tMVR). METHODS: We performed a retrospective cohort analysis of patients with AF undergoing sMVR or tMVR between 04/2014 and 12/2018 using Optum's de-identified Clinformatics® Data Mart Database. We identified anticoagulants prescribed within 90 days of discharge from hospitalization. RESULTS: Overall, 1997 patients with AF underwent valve repair: 1560 underwent sMVR, and 437 underwent tMVR. The mean CHA2DS2-VASc score among all patients was 4.1 (SD 1.9). The overall use of anticoagulation was unchanged between 2014 (72.2%) and 2018 (70.0%) (P = .49). Among patients who underwent sMVR or tMVR between April 2014 and December 2018, the use of VKA therapy decreased from 62.9% to 32.1% (P < .01 for trend) and the use of DOACs increased from 12.4% to 37.3% (P < .01 for trend). CONCLUSIONS: Among patients with AF who underwent sMVR or tMVR between 2014 and 2018, roughly 30% of patients were not treated with any anticoagulant within 90 days of discharge, despite an elevated stroke risk in the cohort. The rate of DOAC use increased steadily over the study period but did not significantly increase the rate of overall anticoagulant use in this high-risk cohort.

Procedure characteristics and outcomes of atrial fibrillation ablation procedures using cryoballoon versus radiofrequency ablation: A report from the GWTG-AFIB registry.

INTRODUCTION: Cryoballoon ablation (CBA) is an alternative to radiofrequency ablation (RFA) for ablation of atrial fibrillation (AF) and real-world comparisons of this strategy are lacking. As such, we sought to compare patient and periprocedural characteristics and outcomes of CBA versus RFA in the Get With the Guidelines AFIB Registry. METHODS: Categorical variables were compared via the χ2 test and continuous variables were compared via the Wilcoxon rank-sum test. Adjusted analyses were performed using overlap weighting of propensity scores. RESULTS: A total of 5247 (1465 CBA, 3782 RFA) ablation procedures were reported from 33 sites. Those undergoing CBA more often had paroxysmal AF (60.0% vs. 48.8%) and no prior AF ablation (87.5% vs. 73.8%). CHA2 DS2 -VASc scores were similar. Among de novo ablations, most ablations involved intracardiac echocardiography and electroanatomic mapping, but both were less common with CBA (87.3% vs. 93.9%, p < .0001, and 87.7% vs. 94.6%, p < .0001, respectively). CBA was associated with shorter procedures (129 vs. 179 min, p < .0001), increased fluoroscopy use (19 vs. 11 min, p < .0001), and similar ablation times (27 vs. 35 min, p = .15). Nonpulmonary vein ablation was common with CBA: roof line 38.6%, floor line 20.4%, cavotricuspid isthmus 27.7%. RFA was associated with more total complications compared to CBA (5.4% vs. 2.3%, p < .0001), due to more volume overload and "other" events, although phrenic nerve injury was more common with CBA (0.9% vs 0.1%, p = .0001). In the adjusted model, any complication was less common among CBA cases (odds ratio, 0.45; confidence interval, 0.25-0.79, p = .0056). CONCLUSION: CBA was associated with fewer complications, and shorter procedure times, and greater fluoroscopy times, compared to RFA. Nonpulmonary vein ablation and electroanatomic mapping system use was common with CBA.

Continuous rhythm monitoring-guided anticoagulation after atrial fibrillation ablation.

INTRODUCTION: Oral anticoagulation (OAC) based on estimated stroke risk is recommended following catheter ablation (CA) of atrial fibrillation (AF), regardless of the extent of arrhythmia control. However, discontinuing OAC in selected patients may be safe. We sought to evaluate a strategy of OAC discontinuation following AF ablation guided by continuous rhythm monitoring. METHODS AND RESULTS: We prospectively studied AF ablations performed at our institution from June 2015 to December 2019. Patients that had pre-existing cardiac implantable electronic devices (CIEDs) or underwent insertable cardiac monitor (ICM) implantation immediately following AF ablation were included. OAC was continued for 6 weeks following CA in all patients, following which OAC management was guided by CHA2 DS2 -VASc score and continuous rhythm monitoring results, according to a prespecified protocol. AF recurrence was defined as ≥30 s (CIEDs) or ≥2 min (ICM). We studied 196 patients (mean age 64.7 ± 11.3 years, 66.8% male, 85.7% ICM, 14.3% CIEDs). Mean CHA2 DS2- VASc score was 2.2 ± 1.5. One-year AF-free survival following CA was 83% for paroxysmal AF and 63% for persistent AF patients. Over 3 year follow-up, OAC was discontinued in 57 (33.7%) patients, mean 7.4 ± 7.1 months following ablation. Following discontinuation, OAC was restarted for AF recurrence in 9 (15.8%) patients, mean 11.7 ± 6.8 months after stopping. This discontinuation protocol led to a 21.9% reduction in overall time exposed to OAC. There were no thromboembolic or major bleeding events. CONCLUSION: OAC can be discontinued in a significant percentage of patients following CA of AF. When guided by continuous rhythm monitoring, this practice does not unacceptably increase the risk of thromboembolic events.

Catheter ablation of ventricular tachycardia in patients with prior cardiac surgery: An analysis from the International VT Ablation Center Collaborative Group.

INTRODUCTION: Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation. METHODS: We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival. RESULTS: There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p < .01), with lower left ventricular ejection fraction (30.2 ± 11.5% vs. 34.8 ± 13.6%, p < .01) and more ischemic heart disease (82.5% vs. 39.3%, p < .01) but less likely to undergo epicardial mapping or ablation (9.0% vs. 38.1%, p<.01) compared to those without prior surgery. When epicardial mapping was performed, a significantly greater proportion required surgical intervention for access (19/52 [36.5%] vs. 14/504 [2.8%]; p < .01). Procedural complications, including epicardial access-related complications, were lower (5.7% vs. 7.0%, p < .01) in patients with versus without prior cardiac surgery. VT-free survival (75.1% vs. 74.1%, p = .805) and survival (86.5% vs. 87.9%, p = .397) were not different between those with and without prior heart surgery, regardless of etiology of cardiomyopathy. VT recurrence was associated with increased mortality in patients with and without prior cardiac surgery. CONCLUSION: Despite different clinical characteristics and fewer epicardial procedures, the safety and efficacy of VT ablation in patients with prior cardiac surgery is similar to others in this cohort. The incremental yield of epicardial mapping in predominant ischemic cardiomyopathy population prior heart surgery may be low but appears safe in experienced centers.

Improvement in tricuspid regurgitation following catheter ablation of atrial fibrillation.

INTRODUCTION: Functional tricuspid regurgitation (TR) remains a challenging clinical problem with poor outcomes and few effective treatments. Atrial fibrillation (AF) has been associated with functional TR. We sought to determine whether restoring sinus rhythm through catheter ablation of AF can decrease the degree of TR. METHODS AND RESULTS: A retrospective cohort study of patients undergoing AF ablation between 2011 and 2017 at a single center was conducted. We included patients with at least moderate TR on echocardiogram within the year preceding ablation, who underwent repeat echocardiogram within the year following ablation. Formal quantitative analysis was performed by an experienced research echocardiographer, blinded to arrhythmia outcomes. Arrhythmia-free survival was correlated to the extent of improvement in TR. Thirty-six patients met the inclusion criteria. A baseline echocardiogram was performed 37 ± 68 days before ablation and follow-up echocardiogram 139 ± 112 days following ablation. Patients were 63.7 ± 11.1 years old with a mean CHA2 DS2 -VASc score of 2.7 ± 1.7. The degree of TR improved by at least one grade in 23 patients (64%). TR area decreased from 11.6 ± 3.4 to 7.0 ± 3.5 cm2 (p < .001) following ablation. Freedom from AF postablation was associated with a greater likelihood of improvement in TR by at least one grade (100% vs. 41%, p = .02). CONCLUSIONS: In patients with AF and at least moderate TR, catheter ablation is associated with substantial improvement in TR severity.

Association of septal late gadolinium enhancement on cardiac magnetic resonance with ventricular tachycardia ablation targets in nonischemic cardiomyopathy.

BACKGROUND: Ablation of septal substrate-associated ventricular tachycardia (VT) in patients with nonischemic cardiomyopathy (NICM) is challenging. We sought to standardize the characterization of septal substrates on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) and to examine the association of that substrate with VT exit and isthmus sites on invasive mapping. METHODS: LGE-CMR was performed before electroanatomic mapping and ablation for VT in 20 NICM patients. LGE extent and distribution were quantified using myocardial signal-intensity Z scores (SI-Z). The SI-Z thresholds correlating to previously validated voltage thresholds, for abnormal tissue and dense scar were defined. RESULTS: Bipolar and unipolar (electrogram) voltage amplitude measurements from the LV and RV were negatively associated with SI-Z from LGE-CMR imaging (p < .05). SI-Z thresholds for appropriate CMR identification of septal substrates were determined to be greater than -.15 for border zone and greater than .03 for a dense scar. Among all patients, 34 critical VT sites were identified with SI-Z distribution in the range of -.97 to .06. Thirty (88.2%) critical sites were located in the dense LGE, 1 (2.9%) in the border zone, and 3 (8.9%) in healthy tissue but within 7 mm of LGE. Of note, critical VT sites were all located at the basal septum close to valves (distance to aortic valve: 17.5 ± 31.2 mm, mitral valve: 21.2 ± 8.7 mm) in nonsarcoidosis cases. CONCLUSIONS: Critical sites of septal VT in NICM patients are predominantly in the CMR defined dense scar when using standardized signal-intensity thresholds.

Collateral injury of the conduction system during catheter ablation of septal substrate in nonischemic cardiomyopathy.

INTRODUCTION: In patients with nonischemic cardiomyopathy (NICM) little is known about the clinical impact of catheter ablation (CA) of septal ventricular tachycardia (VT) resulting in the collateral injury of the conduction system (CICS). METHODS AND RESULTS: Ninety-five consecutive patients with NICM underwent CA of septal VT. Outcomes in patients with no baseline conduction abnormalities who developed CICS (group 1, n = 28 [29%]) were compared to patients with no CICS (group 2, n = 17 [18%]) and to patients with preexisting conduction abnormalities or biventricular pacing (group 3, n = 50 [53%]). Group-1 patients were younger, had a higher left ventricular ejection fraction and a lower prevalence of New York Heart Association III/IV class compared to group 3 while no significant differences were observed with group 2. After a median follow-up of 15 months, VT recurred in 14% of patients in group 1, 12% in group 2 (P = .94) and 32% in group 3 (P = .08) while death/transplant occurred in 14% of patients in group 1, 18% in group 2 (P = .69) and 28% in group 3 (P = .15). A worsening of left ventricular ejection fraction (LVEF) (median LVEF variation, -5%) was observed in group 1 compared to group 2 (median LVEF variation, 0%; P < .01) but not group-3 patients (median LVEF variation, -4%; P = .08) with a consequent higher need for new biventricular pacing in group 1 (43%) compared to group 2 (12%; P = .03) and group 3 (16%; P < .01). CONCLUSIONS: In patients with NICM and septal substrate, sparing the abnormal substrate harboring the conduction system provides acceptable VT control while preventing a worsening of the systolic function.

Association of scar distribution with epicardial electrograms and surface ventricular tachycardia QRS duration in nonischemic cardiomyopathy.

INTRODUCTION: The association of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) with epicardial and surface ventricular tachycardia (VT) electrogram features, in nonischemic cardiomyopathy (NICM), is unknown. We sought to define the association of LGE and viable wall thickness with epicardial electrogram features and exit site paced QRS duration in patients with NICM. METHODS: A total of 19 patients (age 53.5 ± 11.5 years) with NICM (ejection fraction 40.2 ± 13.2%) underwent CMR before VT ablation. LGE transmurality was quantified on CMR and coregistered with 2294 endocardial and 2724 epicardial map points. RESULTS: Both bipolar and unipolar voltage were associated with transmural signal intensity on CMR. Longer electrogram duration and fractionated potentials were associated with increased LGE transmurality, but late potentials or local abnormal ventricular activity were more prevalent in nontransmural versus transmural LGE regions (p < .05). Of all critical VT sites, 19% were located adjacent to regions with LGE but normal bipolar and unipolar voltage. Exit site QRS duration was affected by LGE transmurality and intramural scar location, but not by wall thickness, at the impulse origin. CONCLUSIONS: In patients with NICM and VT, LGE is associated with epicardial electrogram features and may predict critical VT sites. Additionally, exit site QRS duration is affected by LGE transmurality and intramural location at the impulse origin or exit.

Impact of a nurse-led limited risk factor modification program on arrhythmia outcomes in patients with atrial fibrillation undergoing catheter ablation.

BACKGROUND: We have previously demonstrated the feasibility of a nurse-led risk factor modification (RFM) program for improving weight loss and obstructive sleep apnea (OSA) care among patients with atrial fibrillation (AF). OBJECTIVE: We now report its impact on arrhythmia outcomes in a subgroup of patients undergoing catheter ablation. METHODS: Participating patients with obesity and/or need for OSA management (high risk per Berlin Questionnaire or untreated OSA) underwent in-person consultation and monthly telephone calls with the nurse for up to 1 year. Arrhythmias were assessed by office ECGs and ≥2 wearable monitors. Outcomes, defined as Arrhythmia control (0-6 self-terminating recurrences, with ≤1 cardioversion for nonparoxysmal AF) and Freedom from arrhythmias (no recurrences on or off antiarrhythmic drugs), were compared at 1 year between patients undergoing catheter ablation who enrolled and declined RFM. RESULTS: Between 1 November 2016 and 1 April 2018, 195 patients enrolled and 196 declined RFM (body mass index, 35.1 ± 6.7 vs 34.3 ± 6.3 kg/m2 ; 50% vs 50% paroxysmal AF; P = NS). At 1 year, enrolled patients demonstrated significant weight loss (4.7% ± 5.3% vs 0.3% ± 4.4% in declined patients; P < .0001) and improved OSA care (78% [n = 43] of patients diagnosed with OSA began treatment). However, outcomes were similar between enrolled and declined patients undergoing ablation (arrhythmia control in 80% [n = 48] vs 79% [n = 38]; freedom from arrhythmia in 58% [n = 35] vs 71% [n = 34]; P = NS). CONCLUSION: Despite improving weight loss and OSA care, our nurse-led RFM program did not impact 1-year arrhythmia outcomes in patients with AF undergoing catheter ablation.

Use of a novel bipolar sealer device in pocket infections: A case series.

BACKGROUND: Cardiac implantable electronic device pocket infections require complete system removal. However, postoperative bleeding and hematoma can occur after extensive debridement and an optimal management strategy has yet to be defined. METHODS: Following system removal and debridement, all pockets were treated with the Aquamantys bipolar sealer until hemostasis of the underlying tissue was achieved. Clinical characteristics, sealer application time, and postoperative outcomes were analyzed. RESULTS: Thirteen consecutive patients were included with an average age of 61.6 years and 8/13 were male. One patient had both pocket infection and systemic bacteremia. Explanted devices included three pacemakers, nine transvenous implantable cardioverter-defibrillators (ICD), and one subcutaneous ICD. The average number of leads extracted was 2.08 ± 1.04 with a median lead dwell time of 75 months (range, 1-265). Pocket tissue culture yielded Streptococcus anginosus (1), Pseudomonas aeruginosa (2), Staphylococcus epidermidis (1), Staphylococcus aureus (1), and no growth (8). Average time using the Aquamantys was 5.6 ± 2.75 minutes per patient. Twelve out of thirteen pockets were closed by primary intention with one pocket packed and left to heal via secondary intention. A Jackson-Pratt drain was used in three patients and removed within 3 days. There were no hematomas noted during the acute hospitalization or during follow up and all of the wounds healed completely. CONCLUSIONS: Use of a novel bipolar sealing device in lieu of traditional electrocautery provided rapid and durable hemostasis with the ability to close almost all of the pockets via primary intention.

"As Needed" nonvitamin K antagonist oral anticoagulants for infrequent atrial fibrillation episodes following atrial fibrillation ablation guided by diligent pulse monitoring: A feasibility study.

INTRODUCTION: After atrial fibrillation (AF) ablation, oral anticoagulation (OAC) is recommended if stroke risk as assessed by CHA2 DS 2 -VASc score is high. However, patients without AF are often reluctant to take daily OAC. We describe outcome using as needed nonvitamin K antagonist (NOACs) guided by pulse monitoring to detect AF following successful ablation. METHODS AND RESULTS: We identified 99 patients (84% male, age 64 ± 8 years), CHA2 DS 2 -VASc score greater than or equal to 1 in men and greater than or equal to 2 in women (median 2, range 1-6), capable of pulse assessment twice daily and no AF on extended monitoring after AF ablation. All patients were instructed to start NOAC if AF >1 hour or recurrent shorter episodes. Duration of NOAC use after restart was typically 2 to 4 weeks. After 30 ± 14 months (total 244 patient-years), 22 patients (22%) transitioned to daily NOAC because of noncompliance with pulse assessment or patient preference (six patients) or because of suspected or documented AF episode(s) in 16 (16%) patients. Of the remaining 77 (78%), 14 (14%) used NOACs but did not transition back to daily use, most (10 patients) with single use (seven patients) or non-AF rhythm (three patients) documented. There was only one thromboembolic event (0.4%/yr of follow-up) in patient without AF and one mild bleeding event (epistaxis). CONCLUSION: The use of as needed NOACs when AF is suspected with pulse monitoring is effective and safe to maintain low risk of stroke and bleeding after successful ablation. Transition back to daily NOAC use should be anticipated in about one quarter of patients.

Three-dimensional myocardial scar characterization from the endocardium: Usefulness of endocardial unipolar electroanatomic mapping.

Epicardial ablation may be required to eliminate ventricular tachycardia (VT) in patients with underlying structural heart disease. The decision to gain epicardial access is frequently based on the suspicion of an epicardial origin for the VT and/or presence of an arrhythmogenic substrate. Epicardial pathology and VT is frequently present in patients with nonischemic right and/or left cardiomyopathies even in the setting of modest or no endocardial bipolar voltage substrate. In this setting, unipolar voltage mapping from the endocardium serves to help identify midmyocardial and/or epicardial VT substrate. The additional value of endocardial unipolar mapping includes its usefulness to predict the clinical outcome after VT ablation, to determine the irreversibility of myocardial disease, and to guide endomyocardial biopsy procedures to specific areas of intramural scarring. In this review, we aim to provide a guide to the use of endocardial unipolar mapping and its appropriate interpretation in a variety of clinical situations.

P-wave morphology and multipolar intracardiac atrial activation to facilitate nonpulmonary vein trigger localization.

INTRODUCTION: Nonpulmonary vein (non-PV) triggers of atrial fibrillation (AF) are targets for ablation but their localization remains challenging. The aim of this study was to describe P-wave (PW) morphologic characteristics and intra-atrial activation patterns and timing from multipolar coronary sinus (CS) and crista terminalis (CT) catheters that localize non-PV triggers. METHODS AND RESULTS: Selective pacing from six right and nine left atrial common non-PV trigger sites was performed in 30 consecutive patients. We analyzed 12 lead ECG features based on PW duration, amplitude and morphology, and patterns and timing of multipolar activation for all 15 sites. Regionalization and then precise localization required criteria present in at least 70% of assessments at each pacing site. The algorithm was then prospectively evaluated by four blinded observers in a validation cohort of 18 consecutive patients undergoing the same pacing protocol and 60 consecutive patients who underwent successful non-PV trigger ablation. The algorithm for site regionalization included 1) negative PW in V1, ≥30 µV change in PW amplitude across the leads V1-V3, and PW duration ≤100 milliseconds in lead 2 and 2) unique intra-atrial activation patterns and timing noted in the multipolar catheters. Specific ECG and intra-atrial activation timing characteristics included in the algorithm allowed for more precise site localization after regionalization. In the prospective evaluation, the algorithm identified the site of origin for 72% of paced and 70% of spontaneous non-PV trigger sites. CONCLUSION: An algorithm based on PW morphology and intra-atrial multipolar activation pattern and timing can help identify non-PV trigger sites of origin.