Non-sustained ventricular tachycardia (NSVT) Exam with Questions and Solutions

It covers key domains which include; Electrophysiological Mechanisms, Risk Stratification and Prognostic Significance, Clinical Classification and Presentation, Diagnostic Evaluation and Therapeutic Management. A 62-year-old man with prior anterior myocardial infarction and left ventricular ejection fraction (LVEF) of 32% is found to have asymptomatic non-sustained ventricular tachycardia (NSVT) on 24-hour Holter monitoring. Which factor most strongly increases his risk of sudden cardiac death in this context? a. Presence of NSVT alone regardless of structural heart disease b. Reduced LVEF below 35% in the setting of ischemic cardiomyopathy c. Duration of NSVT episodes less than 10 beats d. Absence of syncope during NSVT episodes Correct Answer: b Rationale: In risk stratification for NSVT, the most powerful prognostic determinant is underlying structural heart disease, particularly reduced LVEF. In ischemic cardiomyopathy, an EF ≤35% is a major independent predictor of sudden cardiac death and often guides ICD placement, whereas NSVT alone without ventricular dysfunction has much lower prognostic significance. A 45-year-old woman with hypertrophic cardiomyopathy (HCM) is noted to have short runs of NSVT on ambulatory ECG. Which finding most significantly elevates her risk profile for sudden cardiac death? a. Isolated NSVT without symptoms b. Presence of NSVT combined with massive left ventricular hypertrophy c. Normal blood pressure response to exercise d. Sinus bradycardia at rest Correct Answer: b Rationale: In HCM, NSVT is a recognized risk marker, but its prognostic significance increases substantially when combined with other high-risk features such as massive hypertrophy, family history of sudden death, or unexplained syncope. NSVT alone is not sufficient for high-risk classification without additional markers.