Hypertrophic Cardiomyopathy: Risk of Sudden Death

Topic Overview

Some people who have hypertrophic cardiomyopathy are at high risk for sudden death. It can occur at any age, but it is most shocking when it happens to young adults or athletes. While the media often highlight these tragic deaths, sudden death is rare. It occurs in about 1 out of 100 adults with hypertrophic cardiomyopathy each year.^{footnote 1}

Sudden death is often the result of ventricular tachycardia (a type of rapid heart rate) or other dangerous arrhythmias, which can be caused by hypertrophic cardiomyopathy.

A genetic factor appears to influence which people with hypertrophic cardiomyopathy are more likely to die suddenly. Other risk factors for sudden death include severe blockage of the left ventricle, multiple fainting (syncope) episodes, recurring episodes of ventricular tachycardia, and an abnormal drop in blood pressure during exercise.

To find out your risk of sudden death, your doctor will do tests and ask you about your health and family history. Your doctor might check to see if you:^{footnote 2}

• Have had cardiac arrest or ventricular tachycardia in the past.
• Had a close relative who had hypertrophic cardiomyopathy and died suddenly.
• Have fainted (syncope).
• Have had low blood pressure during or after exercise.
• Have extreme left ventricle thickness (more than 30 millimeters).

If you are at high risk for sudden death, an implantable cardioverter-defibrillator (ICD) might be right for you. An ICD can identify life-threatening arrhythmias and successfully restore a normal heartbeat.

Because of the possible increased risk of sudden death, it is a good idea for family members of people who have hypertrophic cardiomyopathy to learn CPR (cardiopulmonary resuscitation).