Inherited arrhythmia syndromes leading to sudden cardiac death in the young: a global update and an Indian perspective

Abstract

Inherited primary arrhythmias, namely congenital long QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia, account for a significant proportion of sudden cardiac deaths in young and apparently healthy individuals. Genetic testing plays an integral role in the diagnosis, risk-stratification and treatment of probands and family members. It is increasingly obvious that collaborative efforts are required to understand and manage these relatively rare but potentially lethal diseases. This article aims to update readers on the recent developments in our knowledge of inherited arrhythmias and to lay the foundation for a national synergistic effort to characterize them in the Indian population.

Keywords: Cardiac channelopathies; Family screening; Genetic testing; Inherited arrhythmias; Sudden cardiac death.

Fig. 1

Standard 12-lead ECG showing coved ST segment and J-point elevation ≥0.2 mV followed by a negative T wave, termed Type 1 Brugada pattern, in the right precordial leads V1 and V2.

Fig. 2

Standard 12-lead ECGs of LQTS types 1, 2 and 3. Note the prolonged QTc in all three ECGs and the broad based prolonged T wave in LQTS type 1, low amplitude moderately delayed T wave in type 2, and the late appearing non-distinct T wave in type 3.

Fig. 3

Normal resting ECG in a 38-year-old asymptomatic male sibling of a CPVT patient.

Fig. 4

Exercise ECG of a 38-year-old asymptomatic male sibling of a CPVT patient showing bidirectional polymorphic ventricular tachycardia.

Fig. 5

Flowchart for necessary action to establish a comprehensive approach to clinical and genetic evaluation of patients with inherited arrhythmias in India.