Hypertrophic Cardiomyopathy - Treatment Overview

Treatment Overview

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.

Most people with hypertrophic cardiomyopathy should be assessed by a cardiologist to determine their risk for ventricular tachycardia, an abnormally fast heart rate that can result in sudden death. For those in a high-risk category, the implantable cardioverter-defibrillator (ICD) appears to be the most effective treatment for preventing sudden death. In a large study of people with hypertrophic cardiomyopathy who were at high risk of sudden death, ICDs identified ventricular tachycardia and successfully restored a normal heartbeat in some people who had this life-threatening arrhythmia.⁶

Because of the risk of sudden death, it is important for people with hypertrophic cardiomyopathy to avoid too much strenuous activity and intense exercise. About 50% of sudden deaths in people with hypertrophic cardiomyopathy occur during or just after strenuous physical activity.¹ Talk to your doctor about what level of exercise and what kinds of activities are safe. Prolonged activity in hot weather is not recommended, because dehydration can also worsen symptoms in people with hypertrophic cardiomyopathy.

Ongoing treatment

It is important for people with high-risk hypertrophic cardiomyopathy to have frequent check-ups with their doctor. People who are low risk may not see their doctor as often. But you may see the doctor more often if you have a change in your symptoms or your overall health. When symptoms appear or start to get worse, a check-up might include an echocardiogram (echo), electrocardiogram (ECG, EKG), or exercise test. Your doctor will talk about your symptoms and your health history. You may also talk about the health history of people in your family. These regular visits will help your doctor identify any risk factors you may have for sudden cardiac death and other serious medical conditions.

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. After medicines are started, most people need to take them for the rest of their lives.

People with hypertrophic cardiomyopathy who have certain medical or dental procedures are often given antibiotics to help prevent infection from developing in the heart.²

Treatment if the condition gets worse

If you develop serious heart rhythm problems or are at high risk for sudden death, your doctor might recommend an implantable cardioverter-defibrillator (ICD).

Medicines for heart failure may be used if hypertrophic cardiomyopathy progresses to that advanced state. For more information, see the topic Heart Failure.

A surgery called a myectomy or myomectomy may be advised for some people when medicines do not help relieve severe symptoms of heart failure (NYHA class III and IV) due to hypertrophic cardiomyopathy. In this surgery, a portion of overgrown heart muscle is removed. Often the excess muscle tissue is found in the septum, which divides the left and right lower heart chambers (ventricles). An overgrown septum can interfere with the function of the left ventricle and limit blood flow out of the heart. Most people who have this surgery (about 70%) recover well and end up with fewer symptoms. After surgery, physical activity is easier too. These results have been seen for 5 years and longer.³

Another option for people with hypertrophic cardiomyopathy is nonsurgical septal reduction. When the area of the heart muscle that divides the right and left chambers (septum) becomes too thick, the lower left heart chamber (left ventricle) becomes obstructed, which hinders its ability to pump normally. The thickened septum is reduced in size by injecting alcohol into the coronary artery that supplies this area of the heart with blood. The alcohol destroys some of the heart muscle in the thickened septum, thereby reducing the obstruction and improving the left ventricle's pumping ability. Advantages of this procedure are that major surgery and lengthy recovery are avoided because the alcohol can be given through a catheter during a cardiac catheterization procedure. Placement of a permanent pacemaker is sometimes needed after this procedure.⁴

Studies show that this procedure decreases symptoms and increases quality of life over several years. However, long-term effects have not been well studied. Experts recommend that this complex procedure be performed in a large medical center where the staff has substantial experience with it.²

A pacemaker can be implanted surgically to improve the pumping action of the heart. This is done most commonly when there are complications from myectomy or septal reduction. Leads (wires) from the pacemaker are placed on both upper and lower heart chambers (atria and ventricles). Since the pacemaker controls both heart chambers, it is called dual-chamber pacing. Dual pacemakers may also benefit people older than 65 for whom surgery is not an option.² Dual-chamber pacing is not used often but it can be very helpful for a small number of people with hypertrophic cardiomyopathy.

A heart transplant is a treatment option available to a small number of people who have severe, end-stage hypertrophic cardiomyopathy. This procedure involves surgically removing the diseased heart and replacing it with a healthy heart donated by a person who has recently died. There are limited donor hearts available. In addition, the eligibility requirements for a transplant are very specific. For more information, see the topic Heart Failure.