Propafenone-Induced QRS Widening in a Child With Arrhythmogenic Right Ventricular Cardiomyopathy: A Case Report and Literatures Review

Antiarrhythmic Drug Therapy in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable progressive myocardial disorder that predisposes patients to ventricular arrhythmias and sudden cardiac death. Antiarrhythmic medications have an important role in reducing the frequency of ventricular arrhythmias and the morbidity associated with recurrent implantable cardioverter-defibrillator (ICD) shocks. Although several studies have examined the use of antiarrhythmic drugs in ARVC, these have been mostly retrospective in nature and inconsistent in their methodology, patient population and endpoints. Thus, current prescribing practices are largely based on expert opinion and extrapolation from other diseases. Herein, we discuss the major studies of the use of antiarrhythmics in ARVC, present the current approach employed at the Johns Hopkins Hospital and identify areas where further research is needed. Most notably, there is a great need for high-quality studies with consistent methodology and randomized controlled trial data into the use of antiarrhythmic drugs in ARVC. This would improve management of the condition and ensure antiarrhythmic prescribing is based on robust evidence.

Chronic Propafenone Application Increases Functional KIR2.1 Expression In Vitro

Expression and activity of inwardly rectifying potassium (K_IR) channels within the heart are strictly regulated. K_IR channels have an important role in shaping cardiac action potentials, having a limited conductance at depolarized potentials but contributing to the final stage of repolarization and resting membrane stability. Impaired K_IR2.1 function causes Andersen-Tawil Syndrome (ATS) and is associated with heart failure. Restoring K_IR2.1 function by agonists of K_IR2.1 (AgoKirs) would be beneficial. The class 1c antiarrhythmic drug propafenone is identified as an AgoKir; however, its long-term effects on K_IR2.1 protein expression, subcellular localization, and function are unknown. Propafenone's long-term effect on K_IR2.1 expression and its underlying mechanisms in vitro were investigated. K_IR2.1-carried currents were measured by single-cell patch-clamp electrophysiology. K_IR2.1 protein expression levels were determined by Western blot analysis, whereas conventional immunofluorescence and advanced live-imaging microscopy were used to assess the subcellular localization of K_IR2.1 proteins. Acute propafenone treatment at low concentrations supports the ability of propafenone to function as an AgoKir without disturbing K_IR2.1 protein handling. Chronic propafenone treatment (at 25-100 times higher concentrations than in the acute treatment) increases K_IR2.1 protein expression and K_IR2.1 current densities in vitro, which are potentially associated with pre-lysosomal trafficking inhibition.

The Efficacy Comparison Between Guan-Fu Base A Hydrochloric Injection vs. Propafenone Hydrochloric Injection in the Treatment of Arrhythmia: Systemic Review and Meta-Analysis

Objective: To determine using a systematic assessment and meta-analysis if GFA injection is an appropriate substitute of propafenone for arrhythmic. Design: Conduct a systematic review and meta-analysis of randomized controlled trials. Data Source: PubMed, Web of Science, Cochrane Library, Embase, Wan-Fang Database, VIP, CNKI, and Sino Med from their inception to 7 March 2021. Eligibility Criteria for Selecting Studies: Inclusion of randomized controlled trials, which draws a comparison between GFA and propafenone. Evaluation of study integrity and conducted an extraction of independent data. Main Outcome Measure: Efficacy for supraventricular tachycardia, it is considered effective if it is reversed within 40 min (without considering recurrence); for premature ventricular beats, if they are reduced by more than 50% within 6 h. Results: Included in this current study are 1,294 research subjects pooled from 14 clinical studies. From the pooled assessment, GFA is demonstrated to be the equivalent of propafenone regarding the potency of effectiveness for tachycardia (RR = 1.11, 95% CI: 0.96, 1.28, P = 0.15). The subset analysis indicated that GFA has a better effect on premature ventricular beats (RR = 1.35, 95% CI: 1.07, 1.70, P = 0.01) and a similar effect on supraventricular tachycardia (RR = 1.07, 95% CI: 0.98, 1.12, P = 0.21). GFA effectiveness is lesser than propafenone in the case of mean converting time (WMD = -1.18, 95% CI: -2.30, -0.07, P = 0.04), systolic blood pressure (WMD = -3.53, 95% CI: -6.97, -0.09, P = 0.04), and QRS complex (WMD = -3.82, 95% CI: -6.96, -0.69, P = 0.02). Both GFA and propafenone have identical effects for diastolic blood pressure, heart rate, P-R interval, and QTc interval. Conclusion: A meta-analysis of RCTs was performed across 14 clinical trials, whereby 1,294 patients are used as research subjects. From the results, it is revealed that the effect exhibited by GFA injection is similar to the propafenone injection when treating premature ventricular beats or supraventricular tachycardia. Nevertheless, in certain academic disciplines, it was found that GFA is safer and beneficial compared to propafenone. Based on facts from relevant studies, GFA is deemed applicable during clinical practice. Systematic Review Registration: https://www.inplasy.com/inplasy-2021-3-0077/, identifier: INPLASY202130077.