It is primarily an autosomal dominant genetic heart disease in which left ventricular hypertrophy can lead to arrhythmias, heart failure, and sudden death. It is the most common cause of sudden cardiac death in young people and trained athletes. Other less ominous manifestations include dyspnea, chest pain, palpitations, and syncope.
With that in mind, many patients are completely asymptomatic or experience minimal symptoms and have a normal life expectancy without functional limitation. As well, pregnancy is usually well tolerated as long as the patient is kept hydrated. Some patients, however, eventually go on to develop heart failure despite being relatively unaffected for several decades.
ECG usually reveals REPOLARIZATION abnormalities as well as many other nonspecific changes that include left axis deviation, tall R waves with a wide QRS, enlarged/bifid P waves, prominent Q waves in inferior and lateral leads, and inverted T waves. Of these changes, a highly suggestive finding is the combination of left ventricular hypertrophy with left atrial enlargement.
The diagnosis is confirmed with trans-thoracic echocardiography. Exercise stress testing is recommended in order to stratify the patient's level of risk.
Patients must avoid strenuous exercise (e.g., weight lifting), competitive sports, and dehydration. Hot baths and saunas can cause severe peripheral vasodilatation and should also be avoided. On the other hand, casual swimming is allowed.
Treat symptoms and heart failure with a negative inotrope (e.g., β-blockers, verapamil, disopyramide). Asymptomatic patients, however, should not be routinely prescribed a β-blocker for the purpose of preventing sudden cardiac death. A variety of medications should not be given to the patient, including dihydropyridine CCBs (e.g., nifedipine) and positive inotropes (e.g., digoxin). As well, caution is advised when putting the patient on diuretics (e.g., ACEi,) and vasodilators (e.g., nitrates).
Septal reduction therapy (e.g., myotomy, alcohol ablation) is indicated for symptomatic patients who have failed medical therapy. An implantable cardioverter-defibrillator is indicated for patients with a single major risk factor for sudden cardiac death.
All 1st degree relatives should undergo screening with ECG and echocardiography. It is important to note that in patients with evidence of the hypertrophic obstructive cardiomyopathy, a negative genetic test result does not rule out the disease.
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