History and exam

Key diagnostic factors

common

family history of HCM

Autosomal dominant pattern but variable penetrance.

history of presyncope or syncope

Syncope with exertion or without a prodrome is particularly concerning and may be due to either outflow tract obstruction or a ventricular arrhythmia.

systolic ejection murmur

Audible at the lower left edge, accentuated by exercise and standing and lessened by lying supine or squatting.[4]

left ventricular lift (heave)

Best palpated at the left ventricular apex.

double apical impulse or double carotid pulsation

An initial upstroke of the apical impulse or pulse may be felt, followed by a brief collapse and a second impulse. This transient interruption in cardiac output occurs when the anterior leaflet of the mitral valve is pulled into the left ventricular outflow tract during systole (systolic anterior motion of the mitral valve).

uncommon

family history of sudden death

Affected family members may have presented with sudden death, thereby eluding a definitive diagnosis.[4]

Other diagnostic factors

common

younger male (<50 years)

Males are typically diagnosed at a younger age (<50 years) and are often asymptomatic at time of diagnosis (detected on routine clinical evaluation).

HCM is most commonly diagnosed in patients ages 30 to 50 years.[10][12]

dyspnea

Some patients may experience dyspnea.[1]​​[4]

Dyspnea on exertion may be due to left ventricular outflow tract obstruction, diastolic dysfunction, or end-stage heart failure related to HCM.

angina

Some patients may experience angina.[1]​

Chest pain with exertion is particularly concerning and may be due to massive hypertrophy with impaired coronary perfusion, outflow tract obstruction, or myocardial bridging (tunneling of coronary arteries into heart muscle). Atherosclerotic coronary artery disease should also be considered in the adult with exertional chest pain.

palpitations

May represent either ventricular arrhythmias or atrial fibrillation.

irregularly irregular pulse

A sign of atrial fibrillation.

Atrial fibrillation predisposes to thrombus formation and warrants anticoagulation as well as antiarrhythmic therapies.

uncommon

older female (>50 years)

Females are much more likely to be diagnosed at a later age and be symptomatic at the time of diagnosis.[12]

collapse

Patients may present with resuscitated sudden death or syncope with extreme exertion. This may be the only symptom.[4][29]

fourth heart sound

A fourth heart sound (S4) occurs late in diastole and suggests a stiff ventricle or impaired diastolic filling related to hypertrophy.

Fourth heart sound gallop
Fourth heart sound gallop

Auscultation sounds: Fourth heart sound gallop

Risk factors

strong

family history of HCM or sudden cardiac death

Affected family members may have presented with sudden death, thereby eluding a definitive diagnosis.[4]

There may be a family history of ventricular fibrillation or sustained ventricular tachycardia; unexplained syncope; nonsustained ventricular tachycardia, defined as 3 or more beats at ≥120 bpm on ambulatory (Holter) ECG; or maximum left ventricular wall thickness ≥30 mm.[2]

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