ComplicationsBy Mayo Clinic staff
In many people, hypertrophic cardiomyopathy doesn't cause significant health problems. However, in some people, hypertrophic cardiomyopathy can cause severe signs and symptoms, such as shortness of breath, chest pain or fainting.
People with hypertrophic cardiomyopathy are at risk of dangerous abnormal heart rhythms (arrhythmias), such as ventricular tachycardia or ventricular fibrillation. These abnormal heart rhythms can cause sudden cardiac death. Hypertrophic cardiomyopathy is the leading cause of heart-related sudden death in people under 30. Fortunately, such deaths are rare.
Possible complications of hypertrophic cardiomyopathy include:
Arrhythmias. Thickened heart muscle, as well as the abnormal structure of heart cells (disarray), can disrupt the normal functioning of the heart's electrical system, resulting in fast or irregular heartbeats. Atrial fibrillation, ventricular tachycardia and ventricular fibrillation are among the arrhythmias that may be caused by hypertrophic cardiomyopathy.
The most dreaded risk of hypertrophic cardiomyopathy is sudden cardiac death due to ventricular tachycardia or ventricular fibrillation. Unfortunately, it can be difficult to predict which people with hypertrophic cardiomyopathy are most prone to these life-threatening, abnormal heart rhythms. If you experience fainting spells, extreme dizziness or prolonged palpitations, you should seek immediate medical care.
- Obstructed blood flow. In many people, the thickened heart muscle causes obstruction to blood flow leaving the heart. This can lead to shortness of breath with exertion, chest pain, dizziness and fainting spells.
- Mitral valve problems. The thickened heart muscle can leave a smaller space for blood to flow, which in turn causes blood to rush through your heart valves more quickly and more forcefully. This increased force can prevent your mitral valve — the valve between your heart's left atrium and left ventricle — from closing properly. As a result, blood can leak backward into the left atrium. This is called mitral valve regurgitation. Mitral valve regurgitation can lead to other complications, such as heart failure or arrhythmias.
- Heart failure. Heart failure means your heart can't pump enough blood to meet your body's needs. The thickened heart muscle of hypertrophic cardiomyopathy can eventually become too stiff to fill effectively, which can lead to shortness of breath and heart failure.
- Dilated cardiomyopathy. Over time, thickened heart muscle may become weak and ineffective. The ventricle becomes enlarged (dilated), and its pumping ability becomes less forceful.
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