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[Hypertrophic cardiomyopathy manifesting different modes of illness: report of three cases]
M Shida1, Y Miyazaki, K Matsuyama
1Third Department of Medicine, Kurume University School of Medicine.
Insights
Hypertrophic cardiomyopathy (HCM) shows varied left ventricular hypertrophy development. Genetic predisposition can lead to adolescent onset, while others develop it in middle age, sometimes triggered by hypertension.
Area of Science:
- Cardiology
- Genetics
- Internal Medicine
Background:
- Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease.
- Left ventricular hypertrophy (LVH) is a hallmark of HCM, but its onset and progression vary.
- Understanding the diverse presentations of LVH in HCM is crucial for diagnosis and management.
Observation:
- Case 1: A young man with genetic HCM developed asymmetric septal hypertrophy (ASH) and systolic anterior motion of the mitral valve (SAM) during adolescence.
- Case 2: A woman with genetic HCM showed delayed onset of ASH and non-obstructive HCM in middle age.
- Case 3: A middle-aged woman developed ASH, SAM, and an intraventricular pressure gradient, likely secondary to severe hypertension.
Findings:
- LVH in HCM can manifest at different life stages, from adolescence to middle age.
- Genetic predisposition plays a role in early-onset HCM.
- Hypertension may act as a trigger for LVH development in middle-aged individuals with potential HCM.
Implications:
- The variable presentation of LVH in HCM necessitates tailored diagnostic and monitoring strategies.
- Recognizing late-onset HCM is important, even in the absence of a clear family history.
- Further research into the interplay of genetics and environmental factors like hypertension in HCM pathogenesis is warranted.
Abstract:
Three cases of hypertrophic cardiomyopathy (HCM) which presented with different modes of appearance of left ventricular hypertrophy are reported. Case 1: A 24-year-old man had three relatives with HCM. At 13 years of age, he showed no electrocardiographic or echocardiographic abnormalities characteristic of HCM. During the ensuing 11 years, he developed asymmetric septal hypertrophy (ASH) and systolic anterior motion of the mitral valve (SAM), with right bundle branch block and T-wave inversion. Cardiac catheterization confirmed the diagnosis of hypertrophic obstructive cardiomyopathy by demonstrating an intraventricular pressure gradient of 25 mmHg. These observations indicate that this case developed abnormal hypertrophy during adolescence on the basis of genetic predisposition of an autosomal dominant trait. Case 2: A 51-year-old woman had three proven and three possibly affected relatives. At 35 years of age, she had a normal electrocardiogram, although the echocardiogram was not available. Now, 16 years later, she had developed ASH with abnormal Q-waves and was diagnosed as having non-obstructive HCM. These suggest that ASH can be manifested as late as during middle-age, even in those with genetic predisposition. Case 3: A 47-year-old woman was diagnosed as having hypertension and her blood pressure was 190/100 mmHg at 40 years of age, though she had no abnormal electrocardiographic findings and heart murmurs. Now, at 47 years of age, she had developed T-wave inversion, ASH, SAM, and an intraventricular pressure gradient of 50 mmHg. Thus, her ASH appeared during middle-age, and was probably provoked by hypertension, though a complete family survey could not be conducted. These three patients' findings indicate that there may be various modes of appearance of left ventricular hypertrophy in HCM. In the majority of patients with genetic predisposition, abnormal hypertrophy may develop during adolescence as in Case 1. In others, it may develop in middle-age, as it did in Case 2. The disease spectrum of HCM may additionally include those who develop abnormal hypertrophy during middle-age, following provocation by hypertension, as in Case 3.