Name two inherited tachyarrhythmia syndromes associated with sudden cardiac death.

• A. Long QT syndrome and Brugada syndrome
• B. Wolff-Parkinson-White syndrome and Long QT
• C. Brugada syndrome and hypertrophic cardiomyopathy
• D. Catecholaminergic polymorphic VT and short QT syndrome

Answer: (A)

Inherited tachyarrhythmia syndromes are genetic disorders that disrupt the heart’s electric channels, causing dangerous ventricular arrhythmias even when the heart has normal structure. Long QT syndrome lengthens the ventricular repolarization, which shows up as a prolonged QT interval on the ECG and can progress to torsades de pointes and sudden cardiac death, especially with certain triggers. Brugada syndrome stems from sodium-channel dysfunction, often SCN5A–related, and predisposes to ventricular fibrillation with characteristic ECG patterns and higher risk at rest or with fever. These two are classic, well-established inherited conditions linked to sudden death, making them the best answer. Other listed conditions include non-channelopathy scenarios or structural diseases (like hypertrophic cardiomyopathy) or different inherited arrhythmias (such as CPVT or short QT) that can also cause SCD, but the pair most traditionally associated with sudden death as primary tachyarrhythmia syndromes are Long QT syndrome and Brugada syndrome.