07-08-2008, 11:18 PM
A 34-year-old man requests a cardiac consultation because he is concerned about heart disease. He is approaching his 35th birthday, and his father died suddenly at 35 years from an undetermined cause. Six months ago he experienced an episode of syncope while repetitively lifting 150-pound weights. He does not recall any symptoms preceding the episode. He denies any medical illnesses and takes no medications. He occasionally uses cocaine and alcohol.
On physical examination, he is 188 cm tall (74 in) and weighs 90.7 kg (200 lb). Body habitus appears normal. Blood pressure is 125/65 mm Hg in the left arm. Lungs are clear. Cardiac examination shows a grade 2/6 early peaking systolic murmur along the left sternal border, which does not radiate. The murmur accentuates during a Valsalva maneuver and decreases with a maximal sustained hand grip. Extremities are without edema, cyanosis, or clubbing.
Electrocardiography shows increased R-wave voltage in leads V5 and V6 with minimal ST depression and T-wave inversions and a 4-beat salvo of nonsustained ventricular tachycardia. Echocardiography shows asymmetrical left ventricular septal hypertrophy with diastolic septal wall thickness of 3.7 cm. The left atrium is moderately dilated, and a provoked left ventricular outflow tract obstruction due to systolic anterior motion of the mitral valve during a Valsalva maneuver is present.
Which of the following is the most appropriate next management step to prevent sudden cardiac death in this patient?
A Amiodarone
B Metoprolol
C Electrophysiology study
D Implantable cardioverter-defibrillator
On physical examination, he is 188 cm tall (74 in) and weighs 90.7 kg (200 lb). Body habitus appears normal. Blood pressure is 125/65 mm Hg in the left arm. Lungs are clear. Cardiac examination shows a grade 2/6 early peaking systolic murmur along the left sternal border, which does not radiate. The murmur accentuates during a Valsalva maneuver and decreases with a maximal sustained hand grip. Extremities are without edema, cyanosis, or clubbing.
Electrocardiography shows increased R-wave voltage in leads V5 and V6 with minimal ST depression and T-wave inversions and a 4-beat salvo of nonsustained ventricular tachycardia. Echocardiography shows asymmetrical left ventricular septal hypertrophy with diastolic septal wall thickness of 3.7 cm. The left atrium is moderately dilated, and a provoked left ventricular outflow tract obstruction due to systolic anterior motion of the mitral valve during a Valsalva maneuver is present.
Which of the following is the most appropriate next management step to prevent sudden cardiac death in this patient?
A Amiodarone
B Metoprolol
C Electrophysiology study
D Implantable cardioverter-defibrillator