Hypertrophic Cardiomyopathy

Treating Cardiovascular Diseases in Wisconsin and Northern Illinois

Hypertrophic cardiomyopathy (HCM) is genetic heart condition that causes an abnormal thickening of the heart muscle walls. This is a common heart condition, affecting about one out of every 500 people.It is not associated with any particular ethnic group. It affects men and women equally and can lead to sudden cardiac arrest, especially among young athletes. 

HCM occurs when heart muscle cells in the left ventricle enlarge, known as hypertrophy. The region of the left ventricle most commonly affected is the septum, which is the wall that divides the left and right sides of the heart. As the walls thicken, they can block or reduce blood flow from the left ventricle to the aorta, a condition known as hypertrophic obstructive cardiomyopathy.

The thick heart walls often become stiff, making them less likely to relax and fill with blood. This causes pressure to increase inside the heart and the blood vessels of the lungs.  HCM can also cause a disorganized pattern to occur in the muscle cells which can lead to scarring and heart rhythm disturbances. 

Hypertrophic Cardiomyopathy Symptoms

Symptoms of hypertrophic cardiomyopathycan vary greatly. Some people may have this condition and not experience any symptoms.For some patients, the symptoms develop so gradually that they become accustomed to the symptoms and don’t realize there is a problem.

For others, the condition may restrict or block blood flow, causing the ventricles to work harder to pump blood. When this occurs, signs of hypertrophic cardiomyopathy may include:

  • Chest pain
  • Dizziness
  • Fainting (syncope)
  • Heart palpitations (fluttering in the chest), especially with exercise
  • Shortness of breath

Chest pain or pressure often occurs with or right after activity and improves with rest. The pain develops because the thickened heart muscle is demanding more oxygen than it is receiving. For some patients, this also occurs after eating a large meal.  Eating smaller, more frequent meals can help prevent the episodes of pain.

As the heart muscle thickens, it can disrupt the proper function of the mitral valve, which separates the left ventricle from the left atrium. This causes blood to leak back into the left atrium and lungs, resulting in shortness of breath. In most patients, this condition is aggravated by physical activity or eating a large meal.

Palpitations are uncomfortable sensations in the chest that feel like the heart is pounding or racing. These sensations can be a result of an abnormal heart rhythm and may be associated with sweating, shortness of breath or chest pain.

In rare cases, some people with hypertrophic cardiomyopathy experience ventricular tachycardia, a dangerously fast heart rhythm. Unless CPR and defibrillation are initiated immediately after the onset of symptoms, sudden cardiac death can occur.   Every individual with HCM should be assessed on an individual basis to determine their risk for sudden cardiac death. 

Most people with HCM have a low risk for sudden cardiac death. The following items can place patients at higher risk of sudden cardiac death:

  • A family history of sudden cardiac death
  • A very thick ventricle (≥ 30 mm)
  • An abnormal blood pressure response to exercise
  • An episode(s) of fast and abnormal heart rhythms
  • An episode(s) of syncope (fainting)
  • Obstruction of blood flow
  • Overall poor heart function
  • Scarring in the wall of the ventricle on MRI

Risks and Causes of Hypertrophic Cardiomyopathy 

Hypertrophic cardiomyopathy is a familial condition that causes an abnormality in one of the genes that is responsible for how the heart develops and functions.  HCM is inherited through an autosomal dominant manner, meaning there is a 50% chance of passing the disease on to your children.  Currently, 60-70% of people who have the disease have a genetic mutation that can be identified through genetic testing.  This information can then be used to identify the potentially disease-causing mutation in other family members.

Diagnosing Hypertrophic Cardiomyopathy

To diagnose your condition, your doctor will ask about your medical history, conduct a physical exam and perform any of the following cardiac tests:

  • Cardiac catheterization 
  • Cardiac computed tomography
  • Chest X-ray 
  • Electrocardiogram testing, including EKG stress testing or Holter monitor testing
  • Electrophysiology study 
  • Genetic testing
  • Magnetic resonance imaging
  • Ultrasound testing, including echostress testing, transthoracic echocardiogram or transesophageal echocardiogram

Treating Hypertrophic Cardiomyopathy

As with many conditions, doctors treat hypertrophic cardiomyopathy in various ways, depending on the cause, how well the heart is functioning, your age, activity level and the presence of arrhythmias.

Lifestyle changes may include quitting smoking, restricting sodium, limiting alcohol and caffeinated beverages, and avoiding high-intensity sports and weight lifting. Regular physical activity done in moderation is safe and encouraged for overall cardiovascular health. It is important that enough water is consumed to prevent dehydration, including additional beverages when exercise is done.

Your doctor may prescribe beta-blockers and calcium channel blockers to relax the heart muscle, allowing it to fill better and pump more effectively. Angiotensin receptor blockers (ARBs) may be prescribed to control blood pressure, improve symptoms, and enhance heart muscle function. Disopyramide (Norpace) is prescribed to improve symptoms by decreasing the obstruction, if present, in the left ventricle. Spironolactone (Aldactone) is a diuretic that improves fluid balance but also helps prevent scarring from developing in the left ventricle.

You may receive other medications to control your heart rate or decrease the occurrence of arrhythmias. Your doctor may also prescribe antibiotics to reduce the risk of infective endocarditis.

Procedures may include:

  • Alcohol septal ablation, performed in the cath lab and results in a small localized area of muscle damage, which then shrinks and decreases the obstruction
  • Implantable cardioverter defibrillator
  • Septal myectomy, a surgical procedure that removes a portion of the thickened septal wall

A Leader in Treating Complex Cardiovascular Disease

Hypertrophic cardiomyopathy requires appropriate long-term management involving specialized care, close observation and monitoring by experienced and knowledgeable cardiologists.

At our Hypertrophic Cardiomyopathy Center, our experienced specialists use state-of-the-art technology to provide you with expert diagnosis and advanced treatment options.  Most patients with hypertrophic cardiomyopathy have an excellent outlook and are able to lead a normal life without significant problems.

You’ll find our doctors conveniently located throughout eastern Wisconsin and northeastern Illinois. Find a doctor or heart specialist near you. To get a second opinion or if you need assistance finding a provider, please call 888-649-6892.