Clarithromycin, QTc interval prolongation and torsades de pointes:the need to study case reports

BACKGROUND: The manufacturers of clarithromycin sought a drug similar in efficacy to erythromycin but with a superior side-effect profile. They generally achieved this outcome, but postmarketing findings identified a series of reports linking clarithromycin to QTc interval prolongation and torsades de pointes (TdP) ultimately leading to a Black Box Warning. We sought to clarify risk factors associated with TdP among case reports of patients receiving clarithromycin linked to QTc interval prolongation and TdP. METHODS AND RESULTS: In a detailed literature search, we found 15 women, five men, and one boy meeting our search criteria. Among the 17 adults with reported clarithromycin dose and concurrent QTc interval measurement, we found no statistically significant relationship between clarithromycin dose and QTc interval duration. This did not change for the adults who developed TdP. Among adults, major risk factors were female sex (15), old age (11) and heart disease (17). A total of eight adult subjects had all three major risk factors and 14 of the 20 adults had at least two major risk factors. All adult subjects had at least two risk factors besides clarithromycin. A total of four of the 20 adults received cisapride and three received disopyramide. Three adults were considered to suffer from some aspect of the congenital long QT syndrome. CONCLUSIONS: We believe that the risk factor description for this drug should be refined to emphasize the major risk factors of (1) female sex, (2) old age and (3) heart disease

Permanent His bundle pacing: Recommendations from a Multicenter His Bundle Pacing Collaborative Working Group for standardization of definitions, implant measurements, and follow-up

His bundle pacing (HBP) prevents ventricular dyssynchrony and its long-term consequences by preserving normal electrical activation of the ventricles. Since the original description of permanent HBP in 2000, the adoption of HBP has increased over the past several years. However, the reporting of procedural and clinical outcomes to date is not uniform. This article is a collaboration between several implanters with significant experience in HBP to establish a uniform set of definitions encompassing the different forms of HBP as well as define a standardized approach to gathering data end points to ensure consistency in reported outcomes

Multicenter investigation of an implantable cardioverter-defibrillator algorithm to detect oversensing

International audienc

Efficacy and Safety of Pulsed Field Ablation in Atrial Fibrillation: A Systematic Review

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with high morbidity and mortality. AF treatment is guided by a patient–provider risk–benefit discussion regarding drug versus ablation or combination. Thermal ablation has a high rate of adverse events compared to pulsed field ablation (PFA). In this systematic review, we aimed to determine the safety and efficacy of PFA. Methods: The electronic search for relevant articles in English was completed in PubMed, PubMed Central, Cochrane library, Scopus, and Embase databases till July 2022. The screening was completed via the use of Covidence software. The risk of bias assessment and data extraction from the included studies was performed, and the narrative synthesis was performed accordingly. Results: A total of six studies were selected for review and 1897 patients receiving PFA were involved in these studies. Our review was focused on pulmonary vein isolation success, major adverse events, and arrhythmia recurrence. Successful pulmonary vein isolation (PVI) was completed in 100% of cases except in two studies. In one of them, six out of seven patients (86%) in the epicardial cohort had successful PVI. In the MANIFEST-PF survey, the acute PVI success rate was 99.9%. The major complications were rare and included pericardial tamponade, vascular complications requiring surgery, and stroke. The atrial arrhythmia recurrence was higher in the thermal group than in the PFA group (39% vs. 11%). Conclusions: The success rate of PVI by PFA is high, and major adverse events are low. PFA is found to decrease the recurrence of atrial arrhythmia compared to thermal ablation. Substantial randomized controlled trials (RCTs) are needed to validate the efficacy and safety of PFA over conventional methods

Methadone, QTc interval prolongation and torsade de pointes:Case reports offer the best understanding of this problem

We reviewed the literature and found 31 adult cases and 1 newborn case of methadone-associated QTc interval prolongation and/or torsade de pointes (TdP). Parametric statistics may not be useful in studying this issue because methadone-associated TdP is a very rare event and, hence, “an extreme outlier” consistent with scalable randomness. We may have to rely upon narrative medicine in the form of case reports with all its limitations and hazards to provide our best understanding. We report risk factors for methadone-associated QTc interval prolongation and TdP based on review of published case reports. We believe both drug manufacturers and the FDA would better serve our patients and inform clinicians if they more readily reported drug-induced outliers such as methadone-associated TdP using a case report format