Initial treatment

Many people with hypertrophic cardiomyopathy do not need treatment. But in some cases, having a thickened heart muscle can cause problems. If symptoms develop, treatment is usually recommended. Medicines cannot cure hypertrophic cardiomyopathy, but they may be used to treat complications, including atrial fibrillation and heart failure. These medicines include:

• Beta-blockers. Beta-blockers, such as propranolol (Inderal, for example) or atenolol (Tenormin), are often used to treat people who develop symptoms such as shortness of breath or chest pain. They lower blood pressure, slow heart rate, and improve blood flow, which helps decrease symptoms and improves your ability to exercise. They may even prevent or delay the progression of heart failure related to hypertrophic cardiomyopathy.
• Calcium channel blockers. If you do not improve after taking beta-blockers, your doctor will probably try a calcium channel blocker, such as verapamil (Calan or Isoptin, for example). These medicines also slow heart rate and lower blood pressure. Conversely, your doctor may first try a calcium channel blocker and switch to a beta-blocker if you don't get results. These medicines usually are not given at the same time.
• Disopyramide. The antiarrhythmic medicine disopyramide (Norpace) is sometimes used, especially if you have fainting or near-fainting episodes. This medicine can decrease the force with which the heart contracts and reduce the number of abnormal heart rhythms. It helps limit symptoms of heart failure.
• Amiodarone. This is a powerful antiarrhythmic medicine that sometimes is used to treat people with hypertrophic cardiomyopathy who have ventricular tachycardia or atrial fibrillation (two types of rapid heartbeat) or who are at high risk of sudden death. Research on amiodarone continues, but so far the drug has not been shown conclusively to prevent sudden death. In addition, long-term use of amiodarone may cause serious side effects in some people.⁴

Atrial fibrillation occurs in about one in four people with hypertrophic cardiomyopathy. In atrial fibrillation, abnormal electrical impulses cause the upper chambers of the heart (atria) to fibrillate, or quiver, resulting in irregular and rapid beating of the ventricles, the heart's main pump. For most people, this aspect of atrial fibrillation in itself is usually not life-threatening. However, for people who have hypertrophic cardiomyopathy, atrial fibrillation can increase your risk for other abnormal heart rhythms that can be life-threatening. It also increases your risk for heart failure and stroke. For these reasons, most doctors aggressively treat atrial fibrillation in people who have hypertrophic cardiomyopathy. Aggressive treatment usually means using medicines to control the heart rate or rhythm and/or electrical cardioversion to return the heart to its normal rhythm.² For more information, see the topic Atrial Fibrillation.

Anticoagulants often are prescribed for people who have atrial fibrillation. Anticoagulants help protect against blood clots that develop in the heart. Blood clots can be dangerous because they may break loose and travel through the bloodstream (thromboembolism), which may cause a stroke, heart attack, or blocked blood flow to an arm or leg.