A 22-year-old man comes to the office for an exercise evaluation. He is an avid long-distance runner. One of his team members was disqualified recently due to health issues, which made him worried about his health. He has no medical history and does not take any medications or illicit drugs. His maternal grandfather died suddenly at age 40. Blood pressure is 125/75 mm Hg and pulse is 55/min. Transthoracic echocardiogram results are as follows: The right ventricle appears normal and there are no valvular lesions. Which of the following best explains this patient's echocardiogram findings?

Question

A 22-year-old man comes to the office for an exercise evaluation.  He is an avid long-distance runner.  One of his team members was disqualified recently due to health issues, which made him worried about his health.  He has no medical history and does not take any medications or illicit drugs.  His maternal grandfather died suddenly at age 40.  Blood pressure is 125/75 mm Hg and pulse is 55/min.  Transthoracic echocardiogram results are as follows:  The right ventricle appears normal and there are no valvular lesions.  Which of the following best explains this patient's echocardiogram findings?

Quizplus · Accepted Answer

This patient most likely has hypertrophic cardiomyopathy (HCM). Recognition of HCM is important because it is one of the most common causes of sudden cardiac death (SCD) in young adults. Although patients may experience exertional dyspnea, chest pain, lightheadedness, or syncope, they are often asymptomatic. The condition is typically inherited in an autosomal dominant pattern, and patients will often have a family history of HCM or unexplained SCD. Echocardiographic findings consistent with HCM include: Another characteristic of HCM is a poorly developed coronary capillary network in hypertrophied regions with evidence of chronic ischemia (ie, fibrosis, scarring). (Choice A) Anabolic steroid abuse can cause pathologic concentric LV hypertrophy, characterized by reduced diastolic function and poor coronary vascularization. However, uniform ventricular wall thickening would be expected. (Choice B) Athlete's heart involves physiologic cardiac adaptations that improve cardiac function in response to high-level endurance training. There is typically predominant eccentric hypertrophy with enlarged LV cavity size and a small degree of concentric hypertrophy with uniformly increased LV wall thickness. The changes of athlete's heart must be differentiated from those associated with pathologic disease; this patient's reduced LV cavity size and localized septal wall thickening suggest underlying pathology due to HCM. (Choice D) Severe coronary artery disease can lead to ischemic cardiomyopathy, which typically manifests as a dilated cardiomyopathy with an enlarged LV cavity and thin LV walls with impaired systolic function. (Choice E) Viral myocarditis may sometimes lead to dilated cardiomyopathy with eccentric hypertrophy and impaired LV systolic function. Subclinical disease is typically quite mild and resolves without sequelae. Educational objective: Patients with hypertrophic cardiomyopathy (HCM) may be asymptomatic and often have a family history of HCM or sudden cardiac death. Findings consistent with HCM include an overall increase in left ventricular (LV) mass, reduced LV cavity size with impaired diastolic function, LV hypertrophy predominantly affecting the septum, and normal or increased LV ejection fraction.

A 22-Year-Old Man Comes to the Office for an Exercise