Hypertrophic cardiomyopathy (HCM) is defined as thickening of the heart muscle that is not due to abnormal loading conditions like hypertension or valvular heart disease. It is a genetic condition and the estimated prevalence across different populations is about one in 500, which makes it one of the commonest genetic cardiovascular conditions.
A large proportion of patients with this condition may have no symptoms and the diagnosis is usually only made after detection of an abnormal electrocardiogram (ECG) that is done for reasons like health screening. However, in rare instances, its first presentation can be sudden cardiac arrest in a young healthy adult.
Symptoms that result from HCM include chest pain, shortness of breath on exertion, palpitations and occasionally, loss of consciousness. Patient can present with arrhythmia, such as atrial fibrillation or congestive heart failure.
The diagnosis is made by imaging of the heart commonly by echocardiogram or/and cardiac magnetic resonance imaging (MRI).
As HCM is a genetic condition, the goal of treatment is not to cure but to relieve symptoms, treat complications and prevent sudden cardiac arrest for those at high risk.
Majority of patients with no symptoms would not require treatment. In patients suffering from chest pain or breathlessness, medication like beta blocks or calcium channel blockers are usually prescribed. In instances when symptoms are not well controlled with maximal medication, intervention to reduce thickness of a portion of the thickened heart muscle can be carried out; septal ablation reduces the muscle thickness by creating a ‘controlled’ heart attack whereas myectomy is an open heart surgery.
Patients who have family history of sudden cardiac arrest, unexplained fainting spell, severe thickening of heart muscle or dangerous heart rhythm, are considered to be at high risk of sudden cardiac arrest. An implantable cardioverter defibrillator can be life-saving in this group of patients.
Hypertrophic cardiomyopathy (HCM) usually has a benign course. As in any hereditary genetic disease, careful counselling of the condition is important especially on the transmission pattern. Proper risk assessment for sudden cardiac arrest should be done. Anticipating potential complications and instituting appropriate treatment cannot be overemphasised. Long-term monitoring and follow-up would be necessary.
