Hypertrophic Cardiomyopathy: Causes, Symptoms and Treatment
Hypertrophic cardiomyopathy is a condition in which the muscle of the heart (myocardium) gets abnormally thickened thus affecting the blood flow through the body. In most people, this disease does not show any symptoms and they lead a healthy life. But in some people, this condition may be severe, and the symptoms may be apparent. The common symptoms of the disease include shortness of breath and rapid heartbeat. Treatment of hypertrophic cardiomyopathy depends on the severity of the symptoms and includes medications or surgery.
- What is Hypertrophic Cardiomyopathy?
- What Causes Hypertrophic Cardiomyopathy?
- What are the Symptoms of Hypertrophic Cardiomyopathy?
- What are the Risk factors for Hypertrophic Cardiomyopathy?
- What are the Complications of Hypertrophic Cardiomyopathy?
- Diagnosis of Cardiomyopathy
- Treatment of Hypertrophic Cardiomyopathy:
- Other Modes of Treatment Include:
- Prevention of Hypertrophic Cardiomyopathy:
What is Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy is a type of heart disease which has the following characteristics:
- Abnormal thickening of the heart muscle: Thickening of the heart muscle most commonly occurs in the septum of the heart (the segment which divides the two lower chambers of the heart). Thickening of the septum causes narrowing of the left ventricle. This affects the blood flow from the left ventricle to the body tissues(via the aorta).
- Left ventricular stiffness: When the heart muscle thickens, the heart chambers (especially the left ventricle) becomes stiff. This decreases the pumping ability of the heart and if left untreated may eventually lead to heart failure.
- Mitral valve changes: The stiffening of the left ventricle also affects the functioning of the mitral valve (the valve through which blood passes from left atria to left ventricle.)
- Changes in the cells of the heart: The thickened heart cells affects the signal transmission within the heart, giving rise to abnormal rhythms of the heart (arrhythmias).
What Causes Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy may be congenital or acquired. The common causes of hypertrophic cardiomyopathy include:
- Heredity: Some patients acquire the defective gene that causes hypertrophic cardiomyopathy from their parents. Some may inherit these defective genes, but they do not develop the disease and are referred to as carriers of the disease.
- Mutations of genes: Any gene mutations in the normal genes, may also give rise to hypertrophic cardiomyopathy.
- Underlying diseases: In some people, the presence of underlying conditions like obesity, high blood pressureand diabetes may cause hypertrophic cardiomyopathy.
What are the Symptoms of Hypertrophic Cardiomyopathy?
Symptoms may not occur in the initial stages of the disease. But, they become evident as the disease progresses. Some of the common symptoms include:
- Shortness of breath on strenuousphysical activity
- Chest pain or discomfort
- Fluttering or pounding heartbeat
- Generalized weakness or fatigue
- Fainting or dizziness
What are the Risk factors for Hypertrophic Cardiomyopathy?
The following factors increase an individual’s risk of acquiring hypertrophic cardiomyopathy:
- The family history of any heart-related problems like heart attack
- Chronic high blood pressure
- Underlying primary diseases like diabetes and hyperthyroidism
- Post radiotherapy or chemotherapy treatment (for cancer)
- Obesity or overweight
- Excess intake of alcohol regularly
- Excess smoking
- Long-term use of steroids
What are the Complications of Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy typically does not give rise to any complications. But, in some cases, the following difficulties may arise due to a delay in treatment:
- Obstructive heart disease: The thickening of the septum may cause obstruction of the blood flow in the left ventricle. It leads to obstructive heart disease.
- Dilated cardiomyopathy: In patients suffering from hypertrophic cardiomyopathy from a prolonged period, the enlarged cells of the myocardium (heart muscle) starts to weaken. These weak cells gradually dilate the chambers of the heart, leading to dilated cardiomyopathy.
- Atrial fibrillation: The changes in the cells of the heart affects the electrical activity of the heart, and gives rise to an abnormal heart beat. The occurrence of irregular and rapid heartbeat is called as atrial fibrillation.
- Heart failure: The changes in the heart muscles makes it difficult to pump out blood efficiently. Over time, the pumping ability is severely compromised, and the heart may be unable to meet the demands of the body. This is referred to as heart failure.
Diagnosis of Cardiomyopathy
The diagnosis of hypertrophic cardiomyopathy involves the following diagnostic tests.
- Chest x-ray: In this test, x-rays are used to determine the size of the heart and also to view the other structures in the chest.
- Echocardiogram: In this test, sound waves are used to determine the size of the heart and movements of the heart muscle when it beats. It is also useful to analyze the function of the heart valves.
- Electrocardiogram (ECG): The electrocardiogram (ECG) determines any irregularities in the heart rate and rhythm of the heart.
- Exercise stress test: In this test, the patient is asked to perform an exercise program such as walking on a treadmill or cycling on a stationary bi-cycle. Initially, the patient is asked to perform the exercise at his usual pace and eventually, the patient is asked to perform the exercise with an increasing intensity. During this test, the electrical activity of the heart (monitored by an ECG) and the blood pressure of the patient is continuously monitored. Any discrepancy in these readings may indicate an underlying heart disease.
- Holter-monitor test: If a regular electrocardiogram (ECG) does not give any clear idea about the heart rhythm, holter monitor test is performed. In this test, a sensor is fixed to the patient’s body to monitor the heart’s electrical activity continuously (usually for a period of 24 hours).
- Cardiac catheterisation: It is a procedure in which, a catheter is passed into an artery or vein and guided to the heart. This test helps to check the blood pressure and the blood flow within the chambers of the heart. Any abnormal blockages in the arteries can also be visualized.
- Myocardial biopsy: The biopsy involves removal of a small amount of tissue from the heart muscle for microscopic examination. It is performed along with cardiac catheterization. Any increase in the size of the cells of the heart muscle may suggest cardiomyopathy.
- Genetic testing: It is mainly performed to understand the pattern of inheritance of the diseasecausing genes.
Treatment of Hypertrophic Cardiomyopathy:
Based on the severity of symptoms the doctor would plan specific treatment for the patient. They are as follows:
- The doctor would prescribe beta blocker drugs like metoprolol or atenolol and calcium channel blockers such as verapamil or diltiazem. These drugs relax the heart muscles. They also decrease the heart rate to help the heart to pump outblood efficiently.
- Drugs like amiodarone or disopyramide are prescribed as these drug help in maintaining the heart rhythm.
- The doctor would prescribe drugs like warfarin or apixaban to treat atrial fibrillation and to prevent the formation of blood clots.
The doctor would consider treating the patient surgically if medications do not relieve the symptoms. Based on the location of the thickened heart muscle, the surgery is of two types.
- Apical myectomy: In this procedure, the thickened heart muscle near the tip of the heart is removed. In some cases, the surgeon also performs mitral valve repair along with the apical myectomy.
- Septal myectomy: It is an open-heart procedure, where the surgeon removes part of the thickened, overgrown septum between the ventricles.
In this procedure, a catheter (long, thin tube) is inserted into the artery (coronary artery) that supplies blood to the heart. With the help of this catheter, alcohol is injected into the thickened heart muscle to destroy it.
This procedure helps to decrease the symptoms. However, there is a risk of heart block and a disturbance in the electrical activity of the heart which may require implantation of an electronic pacemaker.
Other Modes of Treatment Include:
Implantable cardioverter-Defibrillator (ICD):
This device is prescribed by the doctor for life-threatening heart rhythm disorders such as ventricular tachycardia or ventricular fibrillation. It is also recommended in patientsof hypertrophic cardiomyopathy, whoare at risk of sudden cardiac death due to arrhythmias.
Prevention of Hypertrophic Cardiomyopathy:
Prevention of cardiomyopathy is essential to avoid further life-threatening complications likea sudden heart attack. Taking the following measures help in preventing the complications of cardiomyopathy
- Control of high blood pressure and high cholesterol
- Control of obesity
- Regular physical activity like exercise and walking
- Avoid stressful environment both at work and at home
- Take a healthy diet
Hypertrophic cardiomyopathy is not fatal, at all the times. Early diagnosis and appropriate management help to reduce the risk of complications like sudden heart failure.