Hypertrophic cardiomyopathy (HCM) is a hereditary disorder of heart muscles. It is a condition in which the heart muscles are abnormally thick, especially the left lower chamber of heart (left ventricle). Because of abnormal thickness of the heart muscles, it cannot pump out blood to rest of the body adequately. HCM disorder is one of the most common causes of sudden cardiac death among people below the age of 35 in USA.
Often the disease remains undetected as it does not produce any prominent symptoms, thus a person having this problem may not come to know about it and he lives his normal life.In some cases of HCM a person may experience symptoms such as mild to moderate chest pain, breathlessness and changes in the electrical system of the heart presenting as arrhythmias.
At present there is no specific treatment for hypertrophic cardiomyopathy. Treatment is aimed to minimize the symptoms and prevent its complications. Medicines, pacemaker, and implantation of cardiac defibrillator are choice of treatment.
Signs And Symptoms Of Hypertrophic Cardiomyopathy
Many people with hypertrophic cardiomyopathy may not experience any symptoms. However, in some people HCM may produce symptoms. This may also depend on the extent of muscle thickness and if it contributes in obstruction of the blood flow out of the left ventricle.The symptoms that may occur mostly develop at young age or during active physical work.
Following are some of the symptoms that may be present in hypertrophic cardiomyopathy:
- Pain in chest that may increase with exercise or physical activity. But sometimes chest pain may also occur after rest or even after a meal.
- Breathlessness and fatigue is commonly observed in adult patients. This is because of back flow of blood in the left atrium (left upper chamber) and resulting pressure in lungs.
- Fainting spells occurs due to irregular heartbeats (arrhythmias). It may develop soon after exercise.
- Palpitation or fluttering sensation in the chest.
- In infants the symptoms are difficult to detect. Difficulty in breathing, slow growth, excessive sweating, crying excessively presumably because of chest pain are some of the symptoms.
- Heart murmur detected by the examining doctor while listening with the stethoscope.
Causes Of Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy is a hereditary disease of heart muscles. It is caused due to gene mutation. There is at least 50% risk of inheriting the defective gene even if one parent is suffering from HCM. The abnormality in gene causes thickening of the heart muscles. There is disarray even in fibers of heart muscles. This alteration in muscle fiber of heart can give rise to arrhythmias or abnormal heart rhythm. The thick heart muscles are difficult to relax. Hence it becomes difficult for the blood to fill in heart chambers and pump out blood from the heart.
If the ventricular septum (wall between two ventricles) is thick is may reduce the blood volume in the left ventricle. Its enlargement can obstruct the blood flow out from the heart to rest of the body. This condition is also called obstructive hypertrophic cardiomyopathy.
Sometimes hypertrophic cardiomyopathy can be acquired due to high blood pressure or aging. In other cases the cause of HCM remains unidentified.
Complications Of Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy can cause several complications. This complications may be mild or may be life threatening.
- Arrhythmia: It can cause atrial fibrillation, ventricular tachycardia, ventricular fibrillation. All these abnormalities of heart rhythm can increase risk of fatality.
- Dilated cardiomyopathy: In this condition the thick heart muscles over a period of time will become weak. This may lead to enlargement of left ventricle and finally congestive cardiac failure.
- Weak mitral valve: Mitral valve is situated between upper and lower chamber of left side of heart. Due to back pressure from ventricle some amount of blood flows back to left atrium. The pressure makes mitral valve weak.
- Sudden death: Ventricular arrhythmias are common in hypertrophic cardiomyopathy. It is the cause of sudden cardiac death. Sudden cardiac death among people suffering from HCM is commonly seen below the age of 35 years.
Diagnosis And Treatment Of Hypertrophic Cardiomyopathy
Once the disease is suspected diagnosis can be made with the help of following:
- Physical examination revealing heart murmur with the help of stethoscope.
- Holter monitoring
- Cardiac magnetic resonance imaging.
- X-ray chest
- Stress test
- Cardiac catheterization
There is no cure for hypertrophic cardiomyopathy. Treatment is focused to reduce the symptoms and prevent sudden cardiac death. Treatment also varies according to severity of symptoms. It may depend on the age of patient, his level of physical activity, and more importantly the way his heart is functioning. Hypertrophic cardiomyopathy patient is treated with medications, pacemaker or implantation of cardiac defibrillator depending on the symptoms and severity.
Medicines generally used are beta blockers and calcium channel blockers that help to relax the heart. If the patient has irregular heartbeats, the doctor may prescribe antiarrythmic medicines. Patient may also need to take antibiotics before dental procedures or surgery to reduce the risk of infective endocarditis.
If there is frequent arrhythmias a pacemaker may be necessary to regularize heart rhythm. It is a tiny electronic device that produces electrical signals to regulate heartbeats.
Implantable cardiac defibrillator is used to prevent sudden cardiac death inpatients having severe arrhythmias. It is inserted inside the chest.
Patient must also follow certain lifestyle changes such as reducing physical activity and exercise. Avoiding alcohol and smoking and maintaining healthy weight level.