Maron BJ. Hypertrophic CardiomyopathyA Systematic Review. JAMA. 2002;287(10):1308-1320. doi:10.1001/jama.287.10.1308
Author Affiliation: Minneapolis Heart Institute Foundation, Minneapolis, Minn.
Context Throughout the past 40 years, a vast and sometimes contradictory literature
has accumulated regarding hypertrophic cardiomyopathy (HCM), a genetic cardiac
disease caused by a variety of mutations in genes encoding sarcomeric proteins
and characterized by a broad and expanding clinical spectrum.
Objectives To clarify and summarize the relevant clinical issues and to profile
rapidly evolving concepts regarding HCM.
Data Sources Systematic analysis of the relevant HCM literature, accessed through
MEDLINE (1966-2000), bibliographies, and interactions with investigators.
Study Selection and Data Extraction Diverse information was assimilated into a rigorous and objective contemporary
description of HCM, affording greatest weight to prospective, controlled,
and evidence-based studies.
Data Synthesis Hypertrophic cardiomyopathy is a relatively common genetic cardiac disease
(1:500 in the general population) that is heterogeneous with respect to disease-causing
mutations, presentation, prognosis, and treatment strategies. Visibility attached
to HCM relates largely to its recognition as the most common cause of sudden
death in the young (including competitive athletes). Clinical diagnosis is
by 2-dimensional echocardiographic identification of otherwise unexplained
left ventricular wall thickening in the presence of a nondilated cavity. Overall,
HCM confers an annual mortality rate of about 1% and in most patients is compatible
with little or no disability and normal life expectancy. Subsets with higher
mortality or morbidity are linked to the complications of sudden death, progressive
heart failure, and atrial fibrillation with embolic stroke. Treatment strategies
depend on appropriate patient selection, including drug treatment for exertional
dyspnea (β-blockers, verapamil, disopyramide) and the septal myotomy-myectomy
operation, which is the standard of care for severe refractory symptoms associated
with marked outflow obstruction; alcohol septal ablation and pacing are alternatives
to surgery for selected patients. High-risk patients may be treated effectively
for sudden death prevention with the implantable cardioverter-defibrillator.
Conclusions Substantial understanding has evolved regarding the epidemiology and
clinical course of HCM, as well as novel treatment strategies that may alter
its natural history. An appreciation that HCM, although an important cause
of death and disability at all ages, does not invariably convey ominous prognosis
and is compatible with normal longevity should dictate a large measure of
reassurance for many patients.
Hypertrophic cardiomyopathy (HCM) is a complex and relatively common
genetic cardiac disease that has been the subject of intense scrutiny and
investigation for more than 40 years.1- 10
Hypertrophic cardiomyopathy is an important cause of disability and death
in patients of all ages, although sudden and unexpected death in young people
is perhaps the most devastating component of its natural history. Because
of marked heterogeneity in clinical expression, natural history, and prognosis,11- 20
HCM often represents a dilemma to primary care clinicians and cardiovascular
specialists, even to those for whom this disease is a focus of their investigative
careers. Controversy abounds with regard to diagnostic criteria, clinical
course, and management for which difficult questions often arise, particularly
among practitioners infrequently engaged in the evaluation of HCM patients.
Consequently, it is timely to place in perspective and clarify many of these
relevant clinical issues and profile the rapidly evolving concepts regarding