However, this disease can affect anyone – men, women, and children of all ages – regardless of their physical condition. Hypertrophic Cardiomyopathy is the second most common form of cardiomyopathy, occurring in roughly 0.2% of the general population. The risk of sudden death from Hypertrophic Cardiomyopathy is 2–3% per year. Hypertrophic Cardiomyopathy is characterized by an abnormal thickening of the walls of the heart. Some thickening is normal for healthy persons who exercise or who play competitive sports. In Hypertrophic Cardiomyopathy, however, the thickening becomes extreme. In some patients with HCM, the septum, which separates the left and right sides of the heart, bulges into the left ventricle. Muscles in both ventricles often become enlarged, and these thickened muscle walls may partially block the flow of blood through the aortic valve or prevent the heart from stretching properly and filling with blood. In a small percentage of HCM patients, the mitral valve separating the left atrial and ventricular chambers may also be damaged or may stick to the septum, which causes an obstruction to blood flow through the valve.
Causes of Hypertrophic Cardiomyopathy
A hereditary link has been established for this form of cardiomyopathy. In about half the cases, the person has inherited an abnormal gene from a parent, in the rest of the cases, a gene that is normal at birth later mutates. Fortunately, a genetic test can identify who may be at risk for HCM. Using the results of this test, doctors can warn children at risk to avoid extra exertion and refrain from participating in certain competitive sports. Other causes for HCM have been traced to hypertension and heart valve disease.
Symptoms of Hypertrophic Cardiomyopathy
Fainting during strenuous exercise is often the first and most dramatic symptom of this disease. Other symptoms (if they occur) are shortness of breath, chest pain, and fatigue. Persons who experience these warning signs should seek immediate medical attention. Young athletic adults who die of Hypertrophic Cardiomyopathy usually die before they are diagnosed with the condition. Hypertrophic Cardiomyopathy also may be more difficult to diagnose in athletes because it is similar to a benign condition called left ventricular hypertrophy, an enlargement of the left ventricle that often develops in association with strenuous physical conditioning. Anyone – young or old – who wants to participate in strenuous athletic competition should have a thorough physical exam that includes an Electrocardiogram (ECG or EKG) and chest X–ray.
Diagnosis of Hypertrophic Cardiomyopathy
- A chest X–ray can show if the heart is enlarged.
- An electrocardiogram (ECG or EKG) can indicate chamber hypertrophy or enlargement.
- Echocardiography can be used to detail the dimensions of the heart and the degree of muscle damage.
- Angiography, a cardiac catherization procedure, can provide a detailed view of how well the heart’s arteries, chambers, and valves are functioning.
- Radionuclide studies can provide information on how well the heart has been pumping blood.
- Genetic testing can confirm a diagnosis of Hypertrophic Cardiomyopathy. The National Heart, Lung, and Blood Institute reports that DNA testing has the potential to enhance diagnostic reliability. Genotyping may play an important role in resolving ambiguous diagnoses, such as those in patients who have a borderline or modest increase in left ventricular wall thickness, including trained athletes with ventricular hypertrophy, and some patients with systemic hypertension who are suspected of having HCM.
Often the treatment for this condition address the symptoms rather than the disease itself. Treatments include lifestyle changes, medication, and surgery. For patients with mild to moderate symptoms, drug therapy is often the treatment of choice.
- Beta blockers reduce the force of the heart’s contractions.
- Diuretics reduce excess fluid in the body, relieving the stress on the heart’s pumping action.
- Calcium channel blockers make the muscle–stiffened heart chambers more flexible.
- Antiarrhythmic medications can help regulate the heartbeat.
Surgery for Hypertrophic Cardiomyopathy
In Hypertrophic Cardiomyopathy patients with severe heart damage, surgical repair is recommended
- Surgeons may remove part of the thickened septum (the muscle wall separating the chambers) that is blocking the blood flow. This procedure, called the Morrow operation, eases symptoms in about 70% of patients.
- In patients who have mitral valve damage or where the septum wall is too thin for safe removal of tissue, surgeons may replace the mitral valve.
Patients with serious electrical and blood–flow abnormalities must stay less physically active. Children and young adults who have been genetically determined to be at risk for HCM should avoid strenuous exercise or certain types of athletic competition.