In hypertrophic cardiomyopathy, the heart muscle becomes thicker and stiffer than usual, making it more susceptible to disease. It can interfere with blood pumping, resulting in chest pain, shortness of breath, arrhythmias, heart failure, and sudden cardiac arrest, as well as other symptoms and complications.
Genetic mutations in one of the genes encoding proteins in the heart muscle, called the sarcomere, usually cause HCM. The sarcomere is affected by these mutations, resulting in abnormal growth and contraction of the heart muscle. It can be inherited, meaning that it runs in families, or it can occur spontaneously, meaning that it occurs as a result of a new mutation in a person's DNA. People of African or Asian descent are more likely to suffer from HCM than people of any other age, gender, or ethnicity.
The symptoms of HCM vary depending on the severity of the condition and the part of the heart that is affected. Some people may not have any symptoms, while others may experience:
Chest pain, especially during exercise or emotional stress, due to the reduced blood flow to the heart muscle.
Shortness of breath, especially during exertion or when lying down, due to the impaired filling and pumping of the heart chambers.
Palpitations, or the sensation of a rapid, irregular, or skipped heartbeat, due to the abnormal electrical signals in the heart.
Dizziness, fainting, or lightheadedness, due to the low blood pressure or the lack of oxygen to the brain.
Fatigue, weakness, or reduced exercise tolerance, due to the decreased cardiac output and the reduced oxygen delivery to the body.
HCM can also cause serious complications, such as:
Arrhythmias, or abnormal heart rhythms, such as atrial fibrillation, ventricular tachycardia, or ventricular fibrillation, which can increase the risk of stroke, heart failure, or sudden cardiac death.
Heart failure, or the inability of the heart to meet the body’s needs, which can cause fluid accumulation in the lungs, legs, or abdomen, and worsen the symptoms of HCM.
During exercise, thickened heart muscle or the mitral valve can protrude into the ventricular outflow tract, causing obstruction of blood flow from the left ventricle to the aorta. It can cause severe chest pain, shortness of breath, or fainting.
When the thickened heart muscles or the mitral valve interfere with the closure of the valve, mitral valve regurgitation occurs, or blood leaks from the left ventricle to the left atrium. The increased workload of the heart can result in a heart murmur, or an abnormal sound heard on a stethoscope.
Endocarditis, or the infection of the inner lining of the heart, occurs when bacteria enter the bloodstream and attach to abnormal heart structures. It can cause fevers, chills, night sweats, weight loss, blood clots, and damage to the heart.
HCM can affect the quality of life, the physical and mental health, and the life expectancy of the person. It can also increase the risk of other cardiovascular diseases, such as coronary artery disease, hypertension, or diabetes.
HCM can be diagnosed by a cardiologist, who will perform a physical exam and ask the person about their medical history, their family history, and their symptoms. The cardiologist will also order some tests and procedures, such as:
An electrocardiogram, or ECG, which records the electrical activity of the heart, and can detect the signs of HCM, such as abnormal waves, intervals, or patterns.
An echocardiogram, or echo, which uses sound waves to create images of the heart, and can measure the thickness, size, shape, and function of the heart chambers, valves, and muscle.
A chest X-ray, which uses radiation to produce images of the chest, and can show the enlargement of the heart or the lungs, or the presence of fluid or calcification.
A cardiac MRI, which uses magnetic fields and radio waves to create detailed images of the heart, and can provide more information about the anatomy, physiology, and pathology of the heart.
A cardiac catheterization, which involves inserting a thin tube, called a catheter, into a blood vessel and advancing it to the heart, and can measure the pressure and oxygen levels in the heart chambers, and inject a dye to visualize the coronary arteries and the heart muscle.
A genetic test, which involves taking a blood sample and analyzing the DNA for the presence of a mutation that causes HCM, and can confirm the diagnosis, identify the type of HCM, and screen the family members for the risk of HCM.
The cardiologist will use the results of the tests and the history to determine the diagnosis and the prognosis of HCM, and to prescribe the appropriate treatment.
The treatment of HCM aims to relieve the symptoms, prevent the complications, and improve the survival and the quality of life of the person. The most common treatments are:
Medications, which are used to control the heart rate, the blood pressure, and the arrhythmias, and to reduce the obstruction and the regurgitation. They include:
Beta blockers, which slow down the heart rate and decrease the oxygen demand of the heart muscle.
Calcium channel blockers, which relax the blood vessels and lower the blood pressure and the resistance to the blood flow.
Antiarrhythmics, which stabilize the electrical activity of the heart and prevent the abnormal heart rhythms.
Diuretics, which increase the urine output and reduce the fluid retention and the congestion in the lungs and the body.
Anticoagulants, which thin the blood and prevent the formation of blood clots that can cause stroke or embolism.
HCM can be treated surgically, which is more invasive and definitively, especially if medications do not work or are not tolerated, or if there is severe obstruction, regurgitation, or arrhythmia. The thickened heart muscle is removed or reshaped, the mitral valve is repaired or replaced, or a device that regulates heart rhythm or shocks the heart in case of a cardiac arrest is implanted, such as a pacemaker or a defibrillator. The surgery is performed under general anesthesia, and has a high success rate and a low mortality rate. During the surgery, the patient will need to undergo a thorough evaluation and follow the postoperative instructions carefully. There are risks and complications associated with the surgery, including bleeding, infection, nerve damage, and heart block.
Lifestyle changes, which are important to support the treatment and to prevent the worsening of HCM. They include:
Avoiding strenuous exercise, competitive sports, or heavy lifting, as they can increase the oxygen demand of the heart muscle and trigger the symptoms or the complications of HCM.
Avoiding dehydration, alcohol, caffeine, or tobacco, as they can affect the blood volume, the blood pressure, or the heart rate, and worsen the condition of HCM.
Eating a healthy diet, low in salt, fat, and cholesterol, and high in fiber, fruits, and vegetables, to maintain the body weight and the cardiovascular health.
Managing stress, anxiety, or depression, as they can affect the emotional and mental well-being, and aggravate the symptoms of HCM.
Monitoring the vital signs, such as the blood pressure, the pulse, the temperature, and the weight, and reporting any changes or abnormalities to the doctor.
Taking the prescribed medications, and adjusting them as needed, under the doctor’s supervision.
Following the doctor’s recommendations, regarding the frequency and the type of the tests and the procedures, and the need for the surgery or the device implantation.
The choice of treatment depends on the person’s age, the type and severity of HCM, the presence of symptoms or complications, overall health, and personal preference. In order to help the patient make the best decision, the cardiologist will explain the pros and cons of each option.
HCM cannot be prevented, as it is mostly determined by the genetic and environmental factors that affect the heart muscle and the sarcomere. However, the person can take some steps to protect their health and prevent the progression or the complications of HCM, such as:
Having regular check-ups, at least once a year, or more often if recommended by the cardiologist.
Taking the prescribed medications, and adjusting them as needed, under the cardiologist’s supervision.
Following the proper hygiene and care instructions for the surgery or the device implantation, if applicable, and reporting any signs of infection or malfunction.
Seeking medical attention, if they notice any symptoms of HCM, such as chest pain, shortness of breath, or fainting.
Educating themselves and their family members about HCM, its causes, its symptoms, its diagnosis, its treatment, and its prevention.
HCM is a condition that can affect the person’s well-being and longevity. By understanding the causes, symptoms, diagnosis, treatment, and prevention of HCM, the person can take charge of their health and enjoy a better quality of life.
