Hypertrophic cardiomyopathy is an inherited condition in which the heart muscle, most often the septum, becomes abnormally thick and stiff. It can block blood leaving the left ventricle and is a leading cause of sudden cardiac death in young athletes.
Key symptoms
- Shortness of breath on exertion
- Chest pain with exercise
- Fainting or near fainting during or right after exercise
- Palpitations
- Often no symptoms; found through a murmur or family screening
What you find on exam
- Harsh systolic murmur at the left lower sternal border
- Murmur louder with Valsalva or standing, softer with squatting or handgrip
- Forceful, sustained apical impulse; sometimes an S4
- Family history of sudden death at a young age
Tests
- ECG: left ventricular hypertrophy, deep narrow Q waves, T wave changes
- Echocardiogram: wall thickness of 15 mm or more and outflow obstruction
- Cardiac MRI for scarring; ambulatory monitor for arrhythmias
- Genetic testing and screening of first-degree relatives
Treatment basics
- Beta blocker such as metoprolol, or verapamil if not tolerated
- Avoid dehydration, nitrates and strong diuretics that worsen obstruction
- Mavacamten or septal reduction (myectomy or alcohol ablation) for persistent symptoms
- Implantable defibrillator for patients at high risk of sudden death
- Shared decision about competitive sports
Red flags
- Fainting during exertion
- Sustained palpitations or ventricular tachycardia on the monitor
- Low blood pressure after nitroglycerin or fluid loss
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.