HCM is the most common cause of sudden cardiac death in individuals aged less than 30 years
Hypertrophic cardiomyopathy may develop and manifest at any age. Some may be born with the condition while others may develop it during childhood. The heart may, however, show no signs at this age. In some cases, hypertrophic cardiomyopathy may lead to a stillborn baby. Some infants with hypertrophic myopathy may develop serious complications such as heart failure. The condition is generally silent in children and adolescents who may get incidentally diagnosed when they are screened due to a family history of similar heart conditions.
It is more common for hypertrophic myopathy to develop as the person grows, presenting in the late teens or early twenties. Around half of the adults with this condition develop symptoms. The condition progresses as an increasing thickness of the heart muscles. The diagnosis may be done anytime from birth to ages 80 and beyond. The average age for the diagnosis of hypertrophic cardiomyopathy is around 39 years.
What is hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy or HCM is a medical condition that causes thickening or hypertrophy of the heart muscles (the myocardium). The heart is a muscular organ situated in the chest just behind and slightly towards the left of the breastbone. It roughly measures the size of the closed fist. The heart has four chambers. The upper two chambers are called atria (left and right atria), while the lower two chambers are called ventricles (left and right ventricles). The right atrium and right ventricle are called the right heart while the left atrium and left ventricle are called the left heart. The various chambers of the heart are separated by partitions each of which is called a septum. The flow of blood through the heart is guarded by valves.
Hypertrophic cardiomyopathy is a serious disease that affects the muscles of the heart. This leads to the thickening of the heart chambers (particularly the ventricles), stiffness of the left ventricles, and problems with the mitral valve (the valve between the left atrium and left ventricle). There are also several changes in heart cells making the cells look disorganized and irregular under the microscope. The thickening of the myocardium primarily affects the septum. This along with the thickening of the ventricles leads to the narrowing of the heart chambers. It may perturb and even obstruct the flow of blood from the left ventricle to the aorta (the large blood vessel that carries blood from the heart to the rest of the body). This condition is called hypertrophic obstructive cardiomyopathy or HOCM. In non-obstructive hypertrophic cardiomyopathy, the heart chambers become thickened and stiff affecting their ability to receive and pump blood, but the flow of blood is not obstructed.
What are the symptoms of hypertrophic cardiomyopathy?
The symptoms of hypertrophic cardiomyopathy may vary from person to person depending on the severity of the disease and the age at diagnosis. Some people may not have any symptoms while some may develop symptoms with time. The symptoms may include:
- Chest pain: Chest pain due to hypertrophic cardiomyopathy is typically felt on doing exercise or other forms of physical activity
- Shortness of breath: Patients may complain of easy fatiguability and shortness of breath on doing physical activity. They may report exercise intolerance and feeling tired even when doing a mild activity.
- Dizziness or fainting: Patients may report feeling dizzy or episodes of fainting (syncope). This may be caused by an irregular heart rhythm or a fall in blood pressure. In some patients, there may be no obvious cause of syncopal attacks or fainting episodes.
- Palpitations: This refers to a sensation of racing or pounding heartbeat
- Swelling over the body: Hypertrophic myopathy interferes with the ability of the heart to pump blood effectively. This may lead to fluid accumulation in the body causing swelling, particularly in the feet, legs, belly, and neck veins