Kancharla, Krishna

BACKGROUND: Patients with arrhythmogenic mitral valve prolapse syndrome are at increased risk for life-threatening ventricular arrhythmias, but studies have been limited by small sample sizes. We sought to assemble an international arrhythmogenic mitral valve prolapse syndrome registry to delineate the clinical, imaging, and treatment characteristics of patients with arrhythmogenic mitral valve prolapse syndrome who survived sudden cardiac arrest (SCA) or had sustained ventricular tachycardia (VT) or ventricular fibrillation. METHODS: In this descriptive registry, we characterized patients with arrhythmogenic mitral valve prolapse syndrome who survived SCA, sustained VT, or ventricular fibrillation. Deidentified data were abstracted locally and combined centrally. RESULTS: We included 148 patients who had SCA or VT/ventricular fibrillation. Patients had a mean age of 43.7±15.4 years; 68% were women, 73% had bileaflet prolapse, 65% had mitral annular disjunction, 67% had nonsustained VT, and 59% had inferolateral T-wave inversions. Syncope (n=54, 48%) and anterolateral T-wave inversion (n=26, 22%) were relatively common. Catheter ablation was performed in 50 (35%) patients for premature ventricular complexes and in 18 (17.7%) patients for VT. Sites of origin for arrhythmias were commonly in the papillary muscles, fascicles, mitral annulus, and inferior/inferolateral left ventricle. CONCLUSIONS: In this international descriptive registry of patients with arrhythmogenic mitral valve prolapse syndrome and SCA, patients were young, women, and had bileaflet mitral valve prolapse, mitral annular disjunction, inferolateral T-wave inversions, and nonsustained VT. A history of syncope and anterolateral T-wave inversions was relatively common in patients who survived SCA or sustained VT/ventricular fibrillation.

AbstractObjectiveThis study sought to determine if single‐chamber operation and/or loss of rate response (RR) during elective replacement indicator (ERI) in patients with dual‐chamber pacemakers lead to increased symptom burden, healthcare utilization, and atrial fibrillation (AF).BackgroundDual‐chamber pacemakers often change from dual‐ to single‐chamber pacing mode and/or lose RR functionality at ERI to preserve battery. Single‐chamber pacing increases the incidence of heart failure, AF, and pacemaker syndrome suggesting these changes may be deleterious.MethodsA retrospective analysis of 700 patients was completed. Three comparisons were analyzed: Comparison 1: mode change and RR loss versus no change; Comparison 2: RR loss only versus no change; Comparison 3: mode change only versus no change (in patients with no RR programmed at baseline).ResultsIn Comparison 1, 121 (46%) patients with setting changes experienced symptoms (most often dyspnea and fatigue/exercise intolerance) versus 3 (4%) without setting changes (p < .0001). Similar results were noted in Comparisons 2 and 3 (p = .0016 and p = .0001, respectively). In Comparison 1, patients with setting change sought provider contact more than patients without setting changes (p = .0001). A significant difference was not noted in Comparison 2 or 3. Overall 14 (2%) patients were hospitalized, all of whom had setting changes.ConclusionsSetting changes at ERI including a change from dual‐ to single‐chamber pacing and/or loss of RR results in a significantly increased symptom burden and increased healthcare utilization.

AbstractBackgroundImplantable loop recorders (ILRs) are effective in achieving symptom‐rhythm correlation. However, diagnostic yield in routine clinical practice is not well established.MethodsPatients undergoing ILR implantation between April 2010 and May 2015 were included. All devices were enrolled in remote monitoring with automatic arrhythmia detection and P sense algorithms switched “ON.” Symptom‐rhythm correlation was assessed and changes in management were recorded.ResultsA total of 312 patients (57% male, age 53 ± 22 years; median CHADS2VaSc score = 1) were included in this study. ILRs were implanted for evaluation of syncope in 206 (66.0%), presyncope in 23 (7.4%), unexplained palpitations in 51 (16.3%), and cryptogenic stroke in 27 (8.7%) patients. ILR monitoring yielded a diagnosis that changed management strategy in 146 (46.8%) patients over a median of 12 (1‐42) months. Out of 163 (52.2%) patients with symptoms during the monitoring period, 100 (61.3%) had an arrhythmia. ILR was useful in ruling out an arrhythmic cause for symptoms in 63 (38.7%) patients. ILR results led to pacemaker implantation in 23 patients (7.4% overall and 11.2% of those with syncope) after median follow‐up of 3 months. A new diagnosis of atrial fibrillation was made in 38 (12.2%) patients, 11 of whom were initiated on oral anticoagulants. ILR results led to pacemaker implantation in 31 patients (9.9% overall and 19.0% of those with syncope) after median follow‐up of 3 months. A new diagnosis of atrial fibrillation was made in 38 (12.2%) patients, nine of whom were initiated on oral anticoagulants. Overall, ILR led to a change in management in 47% patients with a number needed to implant of 2.1 to change management.ConclusionILR monitoring is effective in achieving symptom‐rhythm correlation and results in changes in management in nearly half of implanted patients. Additional studies are needed to evaluate cost efficacy of ILR and the optimal monitoring duration.

AbstractIntroductionCatheter ablation (CA) has emerged as the preferred modality of treatment for many cardiac arrhythmias. Anatomical sites of ablation are often located in close proximity to coronary arteries. However, the incidence of CA‐related coronary injury has not been well studied. We sought to systematically evaluate all cases of CA‐related coronary injuries.Methods and ResultsA PubMed search was conducted from inception until May 1, 2017 using the keywords “coronary artery” and “ablation.” We identified 2817 published articles of which 43 articles met our inclusion criteria representing 61 cases of coronary artery injury attributed to CA procedures from 1992 to 2017. Posteroseptal accessory pathway ablation was associated with the highest incidence of coronary injury (35.6% of cases), followed by cavotricuspid isthmus‐dependent flutter (19.3%). The right coronary artery was the site of injury in over two‐thirds of all reported cases. Coronary injury was detected intraprocedurally in about half of the cases (43.1%), whereas it was a delayed presentation in the other half. Coronary intervention was performed in a third of all cases (32.7%). There were a total of three deaths attributed to coronary artery injury.ConclusionsMost (91.8%) coronary injuries are a result of anatomic proximity to the site of ablation. Awareness of the relation between coronary artery course and anatomical site of ablation could prevent myocardial damage and improve procedural safety.

AbstractBackground: The utilization of cardiac resynchronization therapy defibrillator (CRT‐D) has increased significantly, since its initial approval for use in selected patients with heart failure. Limited data exist as for current trends in implant‐related in‐hospital complications and cost utilization. The aim of our study was to examine in‐hospital complication rates associated with CRT‐D and their trends over the last decade.Methods and Results: Using the Nationwide Inpatient Sample, we estimated 378 248 CRT‐D procedures from 2003 to 2012. We investigated common complications, including mechanical, cardiovascular, pericardial complications (hemopericardium, cardiac tamponade, or pericardiocentesis), pneumothorax, stroke, vascular complications (consisting of hemorrhage/hematoma, incidents requiring surgical repair, and accidental arterial puncture), and in‐hospital deaths described with CRT‐D, defining them by the validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code. Mechanical complications (5.9%) were the commonest, followed by cardiovascular (3.6%), respiratory failure (2.4%), and pneumothorax (1.5%). Age (≥65 years), female gender (OR, 95% CI; P value) (1.08, 1.03‐1.13; 0.001), and the Charlson score ≥3 (1.52, 1.45‐1.60; <0.001) were significantly associated with increased mortality/complications.Conclusions: The overall complication rate in patients undergoing CRT‐D has been increasing in the last decade. Age (≥65), female sex, and the Charlson score ≥3 were associated with higher complications. In patients who underwent CRT‐D implantation, postoperative complications were associated with significant increases in cost.

Background: Right ventricular systolic dysfunction (RVD) often coexists with various cardiopulmonary diseases. However, the association between RVD and risk of sudden cardiac death (SCD) has not been well studied. This study examined the risk of SCD associated with RVD in patients with heterogeneous underlying cardiac diseases. Methods: The Mayo Clinic cardiac care unit database included 5463 consecutive patients with complete echocardiographic evaluation to assess right ventricular systolic function and RVD severity. Prospective surveillance follow-up was obtained for all patients. SCD was adjudicated when a malignant ventricular arrhythmia was documented as the primary rhythm leading to death. RESULTS: The prevalence of mild RVD and moderate-severe RVD was 14.9% and 17.1%, respectively. Patients with RVD were more likely to have a history of congestive heart failure, cardiac arrest, pulmonary disease, and lower baseline left ventricular ejection fraction compared with those with normal right ventricular systolic function. During a median follow-up of 14 months, the incidence of SCD was highest in patients with moderate-severe RVD (7.4% versus 4.4% in mild RVD versus 1.6% in normal right ventricular function; P <0.001). After adjustment for baseline characteristics, mild RVD (adjusted hazard ratio, 1.57; P =0.046) and moderate-severe RVD (adjusted hazard ratio, 1.91; P =0.006) were independently associated with an increased risk of SCD. Moderate-severe RVD remained an independent predictor of SCD for patients with left ventricular ejection fraction >35% without or with preexisting implantable cardioverter-defibrillator (adjusted hazard ratio, 4.12; P =0.003 and adjusted hazard ratio, 5.04; P <0.001, respectively). Conclusions: Presence of RVD in patients with a history of preexisting cardiac disease is an independent predictor of SCD irrespective of left ventricular ejection fraction.