Ventricular Arrhythmias

A 48-year-old woman with a structurally normal heart presents with palpitations and syncope. Electrophysiologic study reveals a ventricular arrhythmia arising from the right ventricular outflow tract (RVOT). Which feature most reliably distinguishes idiopathic RVOT VT from scar-related monomorphic VT in a post-MI patient?

Which of the following is the characteristic electrocardiographic finding in Brugada syndrome?

A 52-year-old man with a history of anterior wall myocardial infarction 6 months ago presents with recurrent episodes of palpitations and syncope. On examination, blood pressure is 110/70 mmHg and heart rate is 140 bpm. A 12-lead ECG shows a wide complex tachycardia with a left axis deviation and concordance in the precordial leads. Which investigation is most appropriate to confirm the diagnosis and assess the substrate for arrhythmia?

A 48-year-old woman with dilated cardiomyopathy (EF 25%) presents with a single episode of syncope. Baseline 12-lead ECG shows sinus rhythm with frequent premature ventricular contractions (PVCs). She is on optimal medical therapy (ACE inhibitor, beta-blocker, aldosterone antagonist). Which investigation is most appropriate to risk-stratify her for sudden cardiac death and guide ICD therapy?

A 52-year-old man with dilated cardiomyopathy (ejection fraction 25%) and NYHA Class III heart failure is admitted with recurrent episodes of non-sustained ventricular tachycardia (NSVT) on 24-hour Holter monitoring. He is on optimal medical therapy (ACE inhibitor, beta-blocker, aldosterone antagonist). His electrolytes and renal function are normal. What is the most appropriate next step in management?