La flecainida reduce las arritmias ventriculares en pacientes con taquicardia ventricular polimórfica catecolaminérgica genotipo RyR2 positivo

Impact of face masks during the treadmill exercise tests

INTRODUCTION AND OBJECTIVE

There is little literature on the use of face masks in a treadmill test (TMT) during the COVID-19 pandemic. The objective of this study is to analyze the impact of face masks during a TMT performed during the prepandemic (without face mask) and postpandemic (with face mask) era.

METHODS

Retrospective observational unicentric study of patients undergoing TMT. The inclusion criterion were being over 16years old and having performed at least one TMT in the prepandemic and postpandemic period.

RESULTS

One thousand six hundred fifty-five patients were included in the study. Nine hundred thirty-five (56.5%) were men and 720 (43.5%) women. The mean age was 57.3±14.9 and the mean follow-up time was 15.4 months. Fifty-three percent patients had arterial hypertension, 20% dyslipidemia, 12% diabetes mellitus, 8% smoking habit, 19% personal history of ischemic heart disease, 5% COPD, 8% bronchial asthma, and 8% atrial fibrillation. In almost all the variables studied in PE, including the appearance of ventricular arrhythmias, no significant differences were found, neither by age nor sex, except for the existence of a very slight decrease in exercise capacity with mask use in older patients (>65years).

CONCLUSIONS

The use of surgical or FFP2 face masks during the TMT did not affect functional capacity, blood pressure, heart rate, or increased ventricular arrhythmias.

Flecainide in Ventricular Arrhythmias: From Old Myths to New Perspectives

Flecainide is an IC antiarrhythmic drug (AAD) that received in 1984 Food and Drug Administration approval for the treatment of sustained ventricular tachycardia (VT) and subsequently for rhythm control of atrial fibrillation (AF). Currently, flecainide is mainly employed for sinus rhythm maintenance in AF and the treatment of idiopathic ventricular arrhythmias (IVA) in absence of ischaemic and structural heart disease on the basis of CAST data. Recent studies enrolling patients with different structural heart diseases demonstrated good effectiveness and safety profile of flecainide. The purpose of this review is to assess current evidence for appropriate and safe use of flecainide, 30 years after CAST data, in the light of new diagnostic and therapeutic tools in the field of ischaemic and non-ischaemic heart disease.

Molecular and tissue mechanisms of catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a stress-induced cardiac channelopathy that has a high mortality in untreated patients. Our understanding has grown tremendously since CPVT was first described as a clinical syndrome in 1995. It is now established that the deadly arrhythmias are caused by unregulated 'pathological' calcium release from the sarcoplasmic reticulum (SR), the major calcium storage organelle in striated muscle. Important questions remain regarding the molecular mechanisms that are responsible for the pathological calcium release, regarding the tissue origin of the arrhythmic beats that initiate ventricular tachycardia, and regarding optimal therapeutic approaches. At present, mutations in six genes involved in SR calcium release have been identified as the genetic cause of CPVT: RYR2 (encoding ryanodine receptor calcium release channel), CASQ2 (encoding cardiac calsequestrin), TRDN (encoding triadin), CALM1, CALM2 and CALM3 (encoding identical calmodulin protein). Here, we review each CPVT subtype and how CPVT mutations alter protein function, RyR2 calcium release channel regulation, and cellular calcium handling. We then discuss research and hypotheses surrounding the tissue mechanisms underlying CPVT, such as the pathophysiological role of sinus node dysfunction in CPVT, and whether the arrhythmogenic beats originate from the conduction system or the ventricular working myocardium. Finally, we review the treatments that are available for patients with CPVT, their efficacy, and how therapy could be improved in the future.

Safety and efficacy of flecainide for patients with catecholaminergic polymorphic ventricular tachycardia: A systematic review and meta-analysis

BACKGROUND

Owing to reports of recurrent cardiac events in some catecholaminergic polymorphic ventricular tachycardia (CPVT) patients using β-blockers, safer alternatives are being investigated. Flecainide is an alternative adjunctive anti-arrhythmic agent known to provide incomplete protection to CPVT patients.

METHODS

To investigate the efficacy and tolerability of flecainide, we searched 4 databases for retrospective cohort studies (RCs) and randomized controlled trials (RCTs) investigating the efficacy and safety of flecainide for CPVT patients. Data were extracted and analyzed (risk ratio [RR] or mean difference [MD]) using RevMan software. Seven RCs and 1 RCT (333 CPVT patients; 152 patients treated with flecainide) were identified.

RESULTS

Flecainide monotherapy was superior to standard therapy in alleviating the risk of arrhythmic events (RR = 0.46, confidence interval [CI] = [0.38, 0.56], P < .00001) and exercise-induced arrhythmia scores (MD = -0.39, CI = [-0.74, -0.05], P = .03). Combination therapy of flecainide and β-blockers was superior to β-blocker monotherapy in reducing the risk of arrhythmic and symptomatic events (RR = 0.29, CI = [0.13, 0.69], P = .005; RR = 0.36, CI = [0.20, 0.62], P = .0003, respectively), peak heart rate (MD = -16.81, CI = [-28.21, -5.41], P = .004), and exercise-induced arrhythmia scores (MD = -1.87, CI = [-2.71, 1.04], P < .0001). Flecainide did not increase the risk of all side effects (RR = 0.76, CI = [0.42, 1.40], P = .38) compared to that with β-blockers alone. No deaths were reported among patients treated with flecainide.

CONCLUSIONS

Flecainide is an effective and safe anti-arrhythmic agent, and its use as a monotherapy might be a good alternative for CPVT patients with β-blocker intolerance. Combination therapy was superior to β-blocker monotherapy. More randomized clinical trials are required to explore the long-term efficacy and safety of flecainide in these patients.

Catheter ablation of left posterior fascicular ventricular tachycardia in children with limited fluoroscopy exposure

INTRODUCTION

Catheter ablation of left posterior fascicular ventricular tachycardia in the pediatric population remains challenging, and most studies about this topic have been conducted on adult patients. This study aimed to assess the clinical presentation features and outcomes of catheter ablations performed using limited fluoroscopy with three-dimensional electroanatomic mapping system guidance in a pediatric left posterior fascicular ventricular tachycardia patient group.

METHODS

A total of 20 consecutive patients undergoing left posterior fascicular ventricular tachycardia ablation at a single tertiary centre were enrolled. All children with left posterior fascicular ventricular tachycardia underwent electrophysiological studies using the EnSite NavX system guidance. Ablations were performed during the sinus rhythm based on the Purkinje potentials in all patients.

RESULTS

The mean patient age was 12.7 years (range 2-16), and the mean patient weight was 51 kg (range 11-84). The mean procedure and median fluoroscopy times were 143.1 minutes and 3.4 minutes, respectively. No fluoroscopy was used in three patients. Acute success was achieved in 19 patients (95%). During a mean follow-up of 38.6 ± 19.35 months, left posterior fascicular ventricular tachycardia recurred in four patients (20%). Repeat ablations were performed successfully in those patients who developed recurrences. No complications were seen.

CONCLUSIONS

Catheter ablation of left posterior fascicular ventricular tachycardia in children can be performed safely and effectively with low fluoroscopy exposure using a three-dimensional electroanatomic mapping system.

Cardiac Sympathetic Denervation in Channelopathies

Left cardiac sympathetic denervation (LCSD) is a surgical antiadrenergic intervention with a strong antiarrhythmic effect, supported by preclinical as well as clinical data. The mechanism of action of LCSD in structurally normal hearts with increased arrhythmic susceptibility (such as those of patients with channelopathies) is not limited to the antagonism of acute catecholamines release in the heart. LCSD also conveys a strong anti-fibrillatory action that was first demonstrated over 40 years ago and provides the rationale for its use in almost any cardiac condition at increased risk of ventricular fibrillation. The molecular mechanisms involved in the final antiarrhythmic effect of LCSD turned out to be much broader than anticipated. Beside the vagotonic effect at different levels of the neuraxis, other new mechanisms have been recently proposed, such as the antagonism of neuronal remodeling, the antagonism of neuropeptide Y effects, and the correction of neuronal nitric oxide synthase (nNOS) imbalance. The beneficial effects of LCSD have never been associated with a detectable deterioration of cardiac performance. Finally, patients express a high degree of satisfaction with the procedure. In this review, we focus on the rationale, results and our personal approach to LCSD in patients with channelopathies such as long QT syndrome and catecholaminergic polymorphic ventricular tachycardia.