Risk Stratification in Electrical Cardiomyopathies

Abstract

Electrical cardiomyopathies contain the long QT syndrome (LQTS), the short QT syndrome (SQTS), the Brugada syndrome, and the catecholaminergic polymorphic ventricular tachycardia (CPVT). Patients diagnosed with an electrical cardiomyopathy have an increased risk of syncope and sudden cardiac death (SCD). Usually, we are dealing with young patients or even children. The prevalence of these diseases is low. No large prospective randomized studies exist with respect to outcome based on different clinical and genetic parameters. Thus, risk stratification in these patients is based on retrospective data from single- or multicenter registries.The implantable cardioverter defibrillator is the only reliable therapy in patients with Brugada syndrome and SQTS, as no pharmacological therapy has been proven to prevent SCD. In LQTS and CPVT, the primary therapy relies on beta-blockers. In high-risk patients, the ICD is indicated.In all electrical diseases, risk stratification is based on the clinical phenotype, including the electrocardiogram, the history of unexplained or disease-related syncope, and sudden cardiac arrest. In LQTS and CPVT, demographic data like age and gender are important factors for risk stratification. The genotype contributes to risk stratification only in LQTS and CPVT.Patients with electrical cardiomyopathies have to be risk-stratified individually based on the data and the current guidelines available.

Left cardiac sympathetic denervation for the management of life-threatening ventricular tachyarrhythmias in young patients with catecholaminergic polymorphic ventricular tachycardia and long QT syndrome

“…Despite these favorable results [40], LCSD has not yet found its place in routine or escalating care of patients with drug refractory LQTS and CPVT [41, 42]. Schwartz [25] has recently proposed that LCSD may even alter the necessity of ICD implantation in selected patients, in particular LQT 1 patients [26], who currently meet the class I indication for ICD implantation as adverse events after ICD implantation have been reported to be as high as 25 % in young patients [13].…”

A 'Schwartz score' for short QT syndrome

“…In case of identification of a patient even with a low probability of short QT syndrome, the patient should be risk-stratified, and subsequent treatment should be discussed with a referral center. 9 …”

ICD-Therapie zur Primär- und Sekundärprophylaxe kongenitaler arrhythmogener Erkrankungen

“…Synkopen sind der stärkste Risikofaktor für den plötzlichen Herztod bei LQTS. Über alle Altersgruppen erhöht eine positive Anamnese für Synkopen das Risiko zukünftiger lebensbedrohlicher Arrhythmien um den Faktor 2,7-18 [31]. Im Einzelfall kann auch bei asymptomatischen Patienten mit HochrisikoKonstellationen eine ICD-Implantation erwogen werden.…”