Learning Cardiology

Q. Which one of following echocardiographic features is an important risk factor for sudden cardiac death in HOCM? A.  Gradient of 30 mmHg across left ventricular outflow tract B.  Septal wall thickness of > 3 cm C.  Systolic anterior motion of mitral valve D.  The presence of severe mitral regurgitation    Answer: B. Septal wall thickness of >3 cm Explanation:  Most common cause of SCD in young adults during physical activity and overall also is HOCM. To prevent SCD, Implantable cardioverter defibrillator (ICD) therapy is recommended in patients with  1. Prior cardiac arrest (Class I) 2. Sustained ventricular tachycardia (VT) (Class I)  3. History of SCD in a first-degree relative (Class IIa) 4. Marked LV hypertrophy (Septal thickness more than 3 cm) (Class IIa) 5. Recent unexplained syncope (Class IIa)  6. Nonsustained VT or an abnormal blood-pressure response to exercise (Class IIa)

Q. Most common cardiac mechanism for sudden cardiac death is? A. Ventricular tachycardia B. Ventricular fibrillation C. Asystole D. Bradyarrhythmias Answer: B Ventricular fibrillation is most common mechanism for sudden cardiac deaths.