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.

Electrocardiographic Risk Stratification in COVID-19 Patients.

Background: The COVID-19 pandemic has resulted in worldwide morbidity at unprecedented scale. Troponin elevation is a frequent laboratory finding in hospitalized patients with the disease, and may reflect direct vascular injury or non-specific supply-demand imbalance. In this work, we assessed the correlation between different ranges of Troponin elevation, Electrocardiographic (ECG) abnormalities, and mortality. Methods: We retrospectively studied 204 consecutive patients hospitalized at NYU Langone Health with COVID-19. Serial ECG tracings were evaluated in conjunction with laboratory data including Troponin. Mortality was analyzed in respect to the degree of Troponin elevation and the presence of ECG changes including ST elevation, ST depression or T wave inversion. Results: Mortality increased in parallel with increase in Troponin elevation groups and reached 60% when Troponin was >1 ng/ml. In patients with mild Troponin rise (0.05-1.00 ng/ml) the presence of ECG abnormality and particularly T wave inversions resulted in significantly greater mortality. Conclusion: ECG repolarization abnormalities may represent a marker of clinical severity in patients with mild elevation in Troponin values. This finding can be used to enhance risk stratification in patients hospitalized with COVID-19.

Ventricular Arrhythmia in Septal and Apical Hypertrophic Cardiomyopathy: The French-Canadian Experience.

Background: Apical hypertrophic cardiomyopathy (aHCM) is thought to have a more benign clinical course compared to septal HCM (sHCM), but most data have been derived from Asian cohorts. Comparative data on clinical outcome in Caucasian aHCM cohorts are scarce, and the results are conflicting. The aim of this study was to estimate the prevalence and outcome of aHCM in French-Canadians of Caucasian descent. Methods and results: We conducted a retrospective, single-center cohort study. The primary endpoint was a composite of documented sustained ventricular arrhythmia (VA), appropriate ICD therapy, arrhythmogenic syncope, cardiac arrest, or all-cause mortality. A total of 301 HCM patients (65% males) were enrolled including 80/301 (27%) with aHCM and 221/301 (73%) with sHCM. Maximal wall thickness was similar in both groups. Left ventricular apical aneurysm was significantly more common in aHCM (10 vs. 0.5%; p < 0.001). The proportion of patients with myocardial fibrosis ≥ 15% of the left ventricular mass was similar between aHCM and sHCM (21 vs. 24%; p = 0.68). Secondary prevention ICDs were more often implanted in aHCM patients (16 vs. 7%; p = 0.02). The primary endpoint occurred in 26% of aHCM and 10.4% of sHCM patients (p = 0.001) and was driven by an increased incidence of sustained VA (10 vs. 2.3%; p = 0.01). Multivariate analysis identified apical aneurysm and a phenotype of aHCM as independent predictors of the primary endpoint and the occurrence of sustained ventricular tachycardia. Unexplained syncope and a family history of sudden cardiac death were additional predictors for sustained VA. Apical HCM was associated with an increased risk of ventricular arrhythmia even when excluding patients with apical aneurysm. Conclusions: The phenotype of apical HCM is much more common in French-Canadians (27%) of Caucasian descent compared to other Caucasian HCM populations. Apical HCM in French-Canadians is associated with an increased risk for ventricular arrhythmia.

QT interval prolongation and torsade de pointes in patients with COVID-19 treated with hydroxychloroquine/azithromycin.

Background: There is no known effective therapy for patients with coronavirus disease 2019 (COVID-19). Initial reports suggesting the potential benefit of hydroxychloroquine/azithromycin (HY/AZ) have resulted in massive adoption of this combination worldwide. However, while the true efficacy of this regimen is unknown, initial reports have raised concerns about the potential risk of QT interval prolongation and induction of torsade de pointes (TdP). Objective: The purpose of this study was to assess the change in corrected QT (QTc) interval and arrhythmic events in patients with COVID-19 treated with HY/AZ. Methods: This is a retrospective study of 251 patients from 2 centers who were diagnosed with COVID-19 and treated with HY/AZ. We reviewed electrocardiographic tracings from baseline and until 3 days after the completion of therapy to determine the progression of QTc interval and the incidence of arrhythmia and mortality. Results: The QTc interval prolonged in parallel with increasing drug exposure and incompletely shortened after its completion. Extreme new QTc interval prolongation to >500 ms, a known marker of high risk of TdP, had developed in 23% of patients. One patient developed polymorphic ventricular tachycardia suspected as TdP, requiring emergent cardioversion. Seven patients required premature termination of therapy. The baseline QTc interval of patients exhibiting extreme QTc interval prolongation was normal. Conclusion: The combination of HY/AZ significantly prolongs the QTc interval in patients with COVID-19. This prolongation may be responsible for life-threatening arrhythmia in the form of TdP. This risk mandates careful consideration of HY/AZ therapy in light of its unproven efficacy. Strict QTc interval monitoring should be performed if the regimen is given.

Current Management of Patients with Severe Aortic Regurgitation.

OPINION STATEMENT: Chronic aortic regurgitation can result from various congenital and acquired anomalies and can be associated with proximal aortic disease. As the number of aortic valve procedures is growing, the incidence of post-procedural regurgitation also increases with associated morbidity. Typical evolution is characterized by a clinically silent phase of variable duration followed by a rather rapid decline with high incidence of adverse events. A challenge remains to find the optimal timing for an intervention: Patients are exposed to unnecessary surgical risks if treated prematurely, but peri- and post-operative prognosis is worse when the intervention is performed too late. Clinical evaluation and serial imaging tests can optimize the timing for intervention. Clinical follow-up should try to elucidate associated symptoms, with quantitative measurement of functional capacity as needed. Serial imaging examinations are required to identify sub-clinical left ventricular dysfunction or severe dilatation that should prompt a surgery. At least in selected cases, newer imaging modalities (MRI, 3D echocardiography) and/or biomarkers can help for the management of these patients, and more research is needed to determine if their systematic use can be beneficial. Medical treatment with vasodilators and anti-remodeling drugs can be helpful in some patients but should not replace or delay aortic valve surgery when indicated. Most patients will eventually be treated with surgical aortic valve replacement. Although possible in selected cases, transcatheter aortic valve replacement is not commonly used for patients with pure aortic regurgitation. For patients with prior aortic valve replacement and aortic regurgitation (paravalvular or intravalvular), emerging percutaneous approaches can be considered when available, especially for those at high surgical risk.