Hypertrophic%20cardiomyopathy Signs and Symptoms
Definition
- A genetically determined cardiac disorder characterized by hypertrophy, often of the left ventricle (LV), with nondilated ventricular chambers and no other cardiac or systemic disease (eg aortic stenosis, thyroid disease or hypertension) capable of producing the extent of hypertrophy manifested by the patient
- Maximal LV wall thickness of ≥15 mm in adults or ≥2 standard deviations above the mean for age, sex or body size in children
- Results from mutations in one of the cardiac sarcomere protein genes that encode the parts of the apparatus for contraction: Actin, tropomyosin alpha-1 chain, myosin binding protein C, troponin I, troponin T, beta myosin heavy chain, essential and regulatory light chains
Signs and Symptoms
- Symptoms can range from patients being asymptomatic to mildly or significantly symptomatic with pre-syncopal or syncopal episodes, palpitations, chest pain, decreased exercise tolerance, symptoms of pulmonary congestion (eg fatigue, dyspnea, orthopnea and paroxysmal nocturnal dyspnea) and symptoms of end-stage heart failure
- Life expectancy is normal or near-normal in most patients with hypertrophic cardiomyopathy (HCM) though without possibility of remission; mortality is often due to embolic stroke, heart failure with sudden cardiac death
Epidemiology
- The most common form of genetic cardiovascular disorder occurring in 1 out of 500 individuals regardless of gender or race
- Presents in all age groups
- An autosomal dominant inherited disorder, affected heterozygous individuals beget children with a 50% risk (equal risk for both males and females) of having the gene mutation
- Phenotype is abnormal, frequently focal, hypertrophy that leads to atrial and ventricular arrhythmia, diastolic dysfunction, mitral regurgitation, LV outflow tract obstruction (LVOTO), pulmonary hypertension, myocardial ischemia, coronary insufficiency and congestive heart failure