Some excerpts from my readings
contemporary definition for cardiomyopathy is a myocardial disorder in which the heart muscle is structurally and functionally abnormal in the absence of coronary artery disease, hypertension, valvular disease, and congenital heart disease sufficient to explain the observed myocardial abnormality.
In clinical practice, however, the term “cardiomyopathy” has also been applied to diseases of known cardiovascular cause (eg, “ischemic cardiomyopathy” and “hypertensive cardiomyopathy”).
A 2006 AHA scientific statement proposed a contemporary definition and classification of the cardiomyopathies [4]. The expert consensus panel proposed the following definition: “Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually (but not invariably) exhibit inappropriate ventricular hypertrophy or dilation and are due to a variety of causes that frequently are genetic. Cardiomyopathies either are confined to the heart or are a part of generalized systemic disorders, often leading to cardiovascular death or progressive heart failure-related disability.”
Overview: Primary disease of heart muscle. Three major cardiomyopathy each with different presentation and management plan. They are considered a different disease - although all are disease of heart muscle.
- Dilated Cardiomyopathy has poor systolic contractile function (may effect both ventricles)
- Restrictive Cardiomyopathy has abnormal diastolic relaxation (infiltrative disease e.g. amyloidosis, sarcoidosis), storage disease, fibrotic disorders
- Hypertrophic Cardiomyopathy: marked LV hypertrophy without hypertension or valvular disease.
Presentation: Varies by type - Exercise intolerance, arrythmia, cardiac failure, valvular regurgitation. Many maybe asymptomatic in beginning.
Assessment: Search for the cause. may need cardiac biopsy, genetic testing, cardiac catheterization.
Plan: Treat the cause (immunosuppression) ; manage the symptoms (e.g. manage heart failure); maybe candidates for cardiac transplantation.
Differential diagnosis: heart failure, restrictive cardiomyopathy, myocarditis