Management of Symptoms in Hypertrophic Cardiomyopathy

In 1957, Brock1 made the distinction between congenital subaortic stenosis characterized by a fibrous ridge and “functional subvalvar stenosis” resulting from “muscular hypertrophy,” describing 3 patients with the latter. Brock initially attributed the hypertrophy and resultant outflow obstruction to systemic hypertension, a conclusion he withdrew in a 1959 publication.2 Between these 2 publications, Teare3 described asymmetrical septal hypertrophy in 8 autopsies (from a series of 16 000!). Remarkably, he identified myocyte disarray, proclivity for sudden death during exertion, and occurrence of stroke in association with atrial fibrillation as features of the disease. Quantitative definition of asymmetrical septal hypertrophy as septal to posterior wall thickness ratio ≥1.3 was introduced in 1961.4 The discovery that the left ventricular outflow tract (LVOT) gradient was created by systolic anterior motion (SAM) of the mitral valve was made from analysis of cineangiograms a year later.5Soon thereafter, it was recognized that diverse patterns of hypertrophy existed. In the early 1970s, investigators came to realize that, even among patients with asymmetrical septal hypertrophy, obstruction to left ventricular (LV) outflow at rest was present in only a minority.6 The recognition that an impediment to LV inflow (eg, diastolic dysfunction) might be at least as important as any obstruction to outflow came with the observation that LV end-diastolic pressure (LVEDP) was elevated while LV end-diastolic volume (LVEDV) was normal or low in many patients with hypertrophic cardiomyopathy (HCM).7 The genetic basis of the disease was demonstrated in 1990.8Half a century after the descriptions of Brock and Teare, HCM is now understood to be a disease characterized by idiopathic hypertrophy of the left (and occasionally right) ventricle. Although the disease is often inherited in an autosomal dominant pattern, there are many patients without any relatives who are known to have …