Hypertrophic Cardiomyopathy

Basic Facts

  • Hypertrophic cardiomyopathy means that a segment of the heart muscle wall has become abnormally thickened. This is usually due to a genetic mutation.
  • In some cases, the left ventricular muscle can become thick enough to obstruct blood flow out of the heart, a condition called hypertrophic obstructive cardiomyopathy. 
  • When the muscular walls of the ventricles become thickened, the ventricles are unable to relax sufficiently to fill with blood and the heart becomes unable to pump blood efficiently.

Sometimes, hypertrophic cardiomyopathy can cause an arrhythmia, a disturbance in the heart’s rate or rhythm. In addition, people with hypertrophic cardiomyopathy are susceptible to endocarditis, an infection of the lining of the heart. A physician may recommend that these people take antibiotics before dental procedures and surgery to avoid endocarditis. 

Physicians may also recommend that people with hypertrophic cardiomyopathy avoid:

  • Over-the-counter cold medication,
  • Stimulants (such as cocaine and methamphetamines),
  • Hot tubs and saunas, and
  • Strenuous exercise.

 

 

Many people do not experience any symptoms until the condition is advanced. Rarely, some people have no symptoms prior to sudden death. The symptoms of hypertrophic cardiomyopathy include:

  • Shortness of breath,
  • Chest pain,
  • Dizziness,
  • Lightheadedness or fainting, and
  • Palpitations (awareness of one’s heartbeat).

True hypertrophic cardiomyopathy comes from genetic mutation. High blood pressure can also cause thickening of the muscle.

 

A physician diagnoses hypertrophic cardiomyopathy through a physical examination. The physician may order tests to confirm the diagnosis, including: 

  • Electrocardiography (ECG) – This test records the electrical activity of the heart.
  • Echocardiography – This test uses sound waves to create a moving picture of the heart, showing its size and shape, as well as how the heart chambers and valves are working.
  • Magnetic Resonance Imaging (MRI) - Magnetic and radio wave energy take pictures of the heart’s structure. 
  • Nuclear Imaging – With this test, a tracer is injected into the patient’s bloodstream. Cameras record the distribution of the tracer through the bloodstream and heart muscle and produce images that help physicians evaluate heart function.   
  • Cardiac Catheterization and Angiography - Cardiac catheterization involves the insertion of a thin tube called a catheter into an artery. During angiography, physicians inject dye through the catheter that allows them to study blood flow through the heart and blood vessels and look at the pumping function of the heart.

Hypertrophic cardiomyopathy is usually treated with congestive heart failure medications, including:

  • Beta-blockers, which lower blood pressure and heart rate, reducing the workload on the heart,
  • Calcium channel blockers, which dilate (open) the blood vessels, increasing blood flow to the heart,
  • Antiarrhythmic drugs, which helps correct an abnormal heart rate or rhythm,
  • Diuretics, which reduce fluid retention, a common symptom of heart failure,
  • Anticoagulants, which inhibit blood clot formation by preventing the clumping of platelets in the blood,

A physician may also consider using minimally invasive procedures, such as an alcohol injection to destroy excess tissue. A surgeon may also perform a myomectomy, in which he or she surgically removes part of the thickened muscle. An implantable defibrillator may also be indicated. Similar to a pacemaker, the implantable defibrillator prevents the heart from beating too rapidly.