A 15-year-old male presents for a sports physical. He reports no current symptoms but his maternal uncle died suddenly at age 30 during exercise. On cardiac auscultation, a harsh systolic murmur is heard best at the left sternal border, which increases in intensity with standing and decreases with squatting. What is the most appropriate initial diagnostic test to evaluate this finding?
- AElectrocardiogram (ECG)
- BEchocardiogram
- CCardiac MRI
- DChest X-ray
Show answer & explanationAnswer & explanation
Correct answer: B. Echocardiogram
The patient's history (family history of sudden cardiac death in a young relative) and physical exam findings (harsh systolic murmur at the left sternal border, increasing with standing and decreasing with squatting) are highly suggestive of Hypertrophic Cardiomyopathy (HCM). An echocardiogram is the most appropriate initial diagnostic test as it can directly visualize cardiac structure and function, including left ventricular hypertrophy and outflow tract obstruction, which are hallmarks of HCM.
Why the other options are wrong
- A. An ECG might show left ventricular hypertrophy but is not definitive for HCM and cannot visualize the obstruction.
- C. Cardiac MRI is a highly detailed imaging study but is typically used as a follow-up or in complex cases, not as the initial screening tool for suspected HCM.
- D. A chest X-ray provides limited information about cardiac structure and is not diagnostic for HCM.
Hypertrophic Cardiomyopathy Diagnosis
Hypertrophic Cardiomyopathy (HCM) is a genetic condition characterized by thickening of the heart muscle (left ventricular hypertrophy) without an identifiable secondary cause, often leading to outflow tract obstruction and increased risk of sudden cardiac death.
- Family history of sudden cardiac death, especially in young individuals, is a key risk factor.
- Murmur characteristics: systolic, increases with maneuvers that decrease preload (Valsalva, standing), decreases with maneuvers that increase preload (squatting).
- Echocardiogram is the primary diagnostic tool.
Memory trick: HCM: Heart Murmur Changes, Family History Calls!