A 22-year-old man is brought to the emergency department after he passed out on the field while playing soccer. The episode lasted only 2 minutes and was not associated with any post-event confusion, sleepiness, or weakness. The patient describes himself as "healthy" but on detailed review of systems admits to occasional lightheadedness and vague chest discomfort while playing active sports. His grandfather died suddenly at age 40 from a "heart attack." Blood pressure is 128/74 mm Hg and heart rate is 67/min and regular. On examination, a fourth heart sound is heard at the cardiac apex. There is a 3/6 midsystolic murmur best heard at the left lower sternal border that does not radiate to the base of the heart or to the neck. The patient will most likely benefit from which of the following medications?

Question

A 22-year-old man is brought to the emergency department after he passed out on the field while playing soccer.  The episode lasted only 2 minutes and was not associated with any post-event confusion, sleepiness, or weakness.  The patient describes himself as "healthy" but on detailed review of systems admits to occasional lightheadedness and vague chest discomfort while playing active sports.  His grandfather died suddenly at age 40 from a "heart attack."  Blood pressure is 128/74 mm Hg and heart rate is 67/min and regular.  On examination, a fourth heart sound is heard at the cardiac apex.  There is a 3/6 midsystolic murmur best heard at the left lower sternal border that does not radiate to the base of the heart or to the neck.  The patient will most likely benefit from which of the following medications?

Quizplus · Accepted Answer

11ec25c8_d351_255c_bc81_dbe492e4d233_MD0003_00 This clinical presentation - lightheadedness, chest pain, syncope with exertion, fourth heart sound, and systolic murmur at the left sternal border - is consistent with hypertrophic cardiomyopathy (HCM), likely due to an autosomal dominant genetic mutation (explaining the sudden death of this patient's grandfather at a young age). Depending on the degree of hypertrophy and left ventricular outflow tract (LVOT) obstruction, patients with HCM may have no symptoms or have fatigue, dyspnea, chest pain, palpitations, presyncope, or syncope. Patients with symptoms (eg, syncope, heart failure, angina) should be treated with negative inotropic agents (eg, beta blockers, verapamil, disopyramide) as the initial medical therapy. Beta blockers (eg, metoprolol, atenolol) are the most commonly used agents for initial monotherapy. They prolong diastole and decrease myocardial contractility, which in turn decreases LVOT obstruction and improves symptoms of angina. Non-dihydropyridine calcium channel blockers (eg, verapamil) are sometimes used when symptoms persist despite beta blocker therapy. The term "HCM" is currently preferred to hypertrophic obstructive cardiomyopathy, as some patients with HCM do not have evidence of obstruction. The term is sometimes also used to refer to nonfamilial forms of cardiomyopathy associated with ventricular wall thickness (eg, due to hypertension). (Choice A) Amiodarone is sometimes used for the management of certain arrhythmias (eg, atrial fibrillation). (Choices B and F) Vasodilators, including nitrates (eg, isosorbide mononitrate), dihydropyridine calcium channel blockers (eg, amlodipine, nifedipine), ACE inhibitors, and angiotensin II receptor blockers, can lead to a reduction in left ventricular preload and systemic vascular resistance, with worsening of the LVOT gradient and symptoms. They should be avoided in patients with HCM. (Choices C and G) Aspirin and atorvastatin are used for primary or secondary prevention of coronary or cerebrovascular events in patients at high risk or who have a prior history of coronary heart disease. These medications have no role in the management of HCM. (Choice D) Digoxin is an inotropic agent that is occasionally used in patients with heart failure due to left ventricular systolic dysfunction. (Choice E) Disopyramide is an antiarrhythmic drug with negative inotropic properties. It is sometimes used in addition to a beta blocker or verapamil in patients with HCM who have persistent symptoms of heart failure and LVOT obstruction. However, it has significant side effects, including the risk of proarrhythmias, and is not considered a first-line agent for medical therapy. (Choice I) Ranolazine is an antianginal agent that is used occasionally in patients with chronic stable angina refractory to standard antianginal medications (eg, nitrates, beta blockers, calcium channel blockers). Educational objective: Negative inotropic agents (eg, beta blockers, verapamil, disopyramide) are recommended for the pharmacological management of symptomatic patients with hypertrophic cardiomyopathy. Beta blockers are preferred for initial therapy, and verapamil or disopyramide can be used as additional therapy in patients with persistent symptoms. References: 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/22068434)

A 22-Year-Old Man Is Brought to the Emergency Department After