Curriculum · Cardiovascular and Hypertension
Hypertrophic obstructive cardiomyopathy
What it is
Hypertrophic obstructive cardiomyopathy is hereditary in more than 60% of cases and is transmitted as an autosomal dominant trait. An abnormality on chromosome 14 has been identified in the familial form of the disease. The distinctive hallmark of the disease is unexplained myocardial hypertrophy, usually with thickening of the interventricular septum.
How it presents
Dyspnea, angina, presyncope, syncope with exertion, and palpitations. The symptoms are dyspnea, chest pain or exercise-induced syncope. On examination: a large jugular A wave, a bifid carotid pulse, a palpable S4 gallop, a systolic murmur and thrill, and a mitral regurgitation murmur. In one case a previously healthy 18-year-old has shortness of breath on exertion with occasional chest pain, a positive family history for sudden death below the age of 50, and a mid-systolic murmur at the left sternal edge. Sudden death can sometimes be the first manifestation.