Related Articles
Hypertrophic cardiomyopathy (HCM) is a disease of the heart in which the heart muscle of an individual becomes abnormally thick.
Hypertrophic cardiomyopathy (HCM) is a disease of the heart in which the heart muscle of an individual becomes abnormally thick. The thickened heart muscle makes it harder for the heart to pump blood and makes the heart prone to a rare but serious rhythm dysfunction.
In most patients, HCM is never diagnosed or diagnosed late in life by accidental detection of a heart murmur or during routine screening. Sometimes, a fainting attack while running a marathon may prompt a diagnosis.
Although HCM is the most frequent cause of sudden heart death among young, trained athletes, it can be well managed if detected during screening or before any exertional activity.
Contrary to the popular belief, people with HCM can live a long life, almost equal to the general population. However, they require frequent screening, medications, and supervised physical exertion.
According to recent study, majority of the affected people have few or no symptoms. Research has shown that with proper treatment and follow-ups, most people with HCM live a normal life. A database of 1,297 patients with HCM from the Minneapolis Heart Institute Foundation identified that 2% of the patients can live past 90 years, and 69% of them were women.
What does hypertrophic cardiomyopathy mean?
Hypertrophic cardiomyopathy (HCM) is a disease of the heart muscle. It is often caused by a change in one or more genes (unit of heredity) that can be passed on through in the family.
In this disease, the heart muscle becomes excessively thick, making it harder for the heart to pump blood out of the heart and around the body.
About 1 in 500 of the general population has HCM, although most people who have it may not exhibit symptoms. It is a truly global disease, affecting people of both sexes, ages, and various ethnic and racial origins.
What are the causes of HCM?
Hypertrophic cardiomyopathy (HCM) is commonly caused by inherited faulty genes (unit of heredity). In this disease, more than 1,400 gene changes (mutations) occur in the heart muscle. People with HCM often have a pattern of inheritance on a pair of autosomal chromosome (non-sex chromosome).
What are the symptoms of HCM?
There is a wide variation in the symptoms of hypertrophic cardiomyopathy (HCM). Some may have few or no symptoms, whereas some may represent very severe symptoms:
- Shortness of breath while climbing upstairs or running or jogging
- Dizziness or fainting while standing quickly
- Light-headedness
- Passing out
- Palpitations (feeling the heart beating too fast)
- Chest pain that radiates to the back, tummy, or left shoulder
- Tiredness for no particular reason
- Arrhythmias (abnormal heartbeats): These are faster, slower, or unsteady heartbeats that may be fatal in rare cases. These include:
- Atrial fibrillation: It is a very quick and uncoordinated heartbeat. This may result in a stroke.
- Ventricular tachycardia: In this, the heart abnormally contracts faster (>100 beats/minute) due to abnormal electrical activity in the ventricle (heart’s large chamber) causing the heart to dysfunction.
- Ventricular fibrillation: Regulation of the heartbeat is interrupted by multiple abnormal impulses generated in the ventricles. It stops the pumping of the blood out of the heart and can be life-threatening.
- Sudden heart block: Electrical impulse travel down to the ventricles slowly or may even be completely blocked causing the heart to abruptly stop beating.
Suspicion of HCM usually follows the onset of symptoms, a cardiac event, or by recognition of abnormal signs during a physical examination and confirmed conventionally by an echocardiography (two-dimensional [2D] echo) or a magnetic resonant imaging (MRI) scan.
People born with these genetic changes may not develop the symptoms until teenage years or may not even have any symptoms in their lives. Sometimes, HCM may occur later in life. Therefore, the cardiologist may advise a person with HCM to screen their first-degree relatives (children, siblings, and parents), which usually involves echocardiogram, electrocardiogram, and genetic testing.
Are there any treatment options for HCM?
Effective treatment strategies for hypertrophic cardiomyopathy (HCM) are available that include:
- Medications: These are not always given to people with HCM. However, they might be helpful in some cases such as:
- Beta-blockers: To prevent arrhythmias or reduce symptoms of obstruction
- Anti-arrhythmic medication: To reduce abnormal heart rhythms and control the normal rhythm
- Blood thinners: Used in people with abnormal heartbeats to reduce the risk of blood clot forming, which could lead to a stroke
- Calcium channel blockers: Special group of calcium channel blockers such as verapamil or diltiazem may be given in some cases
- Devices: If medications fail, an implanted device might reverse these arrhythmias such as:
- Implantable cardioverter–defibrillator: It detects and corrects a potentially abnormal heartbeat that could otherwise lead to sudden heart failure and death.
- Pacemaker: It sends electrical impulses on demand, or continuously, to take over the electrical signaling of the heart and maintain a normal rhythm.
- Alcohol septal ablation
- Septal reduction or a myectomy surgery to reduce heart muscle thickening and eventually prevent the dysrhythmia risk.