Hypertrophic Cardiomyopathy – Symptoms and Causes
Overview
Hypertrophic cardiomyopathy (HCM) is a condition where the heart muscle thickens abnormally. This thickening makes it harder for the heart to pump blood effectively throughout the body.
Most people with HCM don’t know they have it because symptoms are often mild or absent. However, some individuals experience serious symptoms including:
- Shortness of breath
- Chest pain
- Irregular heartbeats
The thickened heart muscle can sometimes affect the heart’s electrical system. This disruption may lead to dangerous heart rhythm problems or, in rare cases, sudden death.
Signs and Symptoms
People with hypertrophic cardiomyopathy may experience several symptoms. These can include chest pain during physical activity.
Some individuals might faint, particularly while exercising or just after physical exertion.
Other common symptoms include feeling like your heart is beating unusually fast or hard (palpitations). Many people also notice they become short of breath easily, especially during exercise.
When to Get Medical Help
If you have a family history of hypertrophic cardiomyopathy or notice any symptoms related to this condition, it’s important to see your doctor promptly.
Many different health problems can cause similar symptoms, so proper diagnosis is essential.
Seek emergency medical attention by calling 911 if you experience:
- Fast or irregular heartbeat that lasts longer than a few minutes
- Difficulty breathing
- Chest pain that doesn’t go away quickly
These symptoms require immediate medical evaluation as they could indicate a serious problem.
Causes
Hypertrophic cardiomyopathy develops primarily from genetic changes that lead to an abnormal thickening of heart muscle. This inherited condition typically affects the septum—the wall dividing the heart’s lower chambers (ventricles).
The condition appears in two main forms:
Obstructive Hypertrophic Cardiomyopathy:
- Thickened septum blocks blood flow leaving the heart
- May cause symptoms during physical activity
- Often creates a heart murmur
Nonobstructive Hypertrophic Cardiomyopathy:
- No significant blockage of blood flow
- Left ventricle becomes stiff and less flexible
- Reduced blood volume pumped with each heartbeat
- Heart cannot fill properly between beats
At the cellular level, heart muscle cells become disorganized in a pattern called myofiber disarray. This irregular arrangement of cells can disrupt the heart’s electrical system, potentially triggering abnormal heart rhythms in some patients.
Most people inherit this condition from a parent, though some cases develop from new genetic mutations with no family history of the disease.
Factors Increasing Risk
Hypertrophic cardiomyopathy often runs in families through genetic inheritance. If one parent has this heart condition, their children face a 50% chance of inheriting the gene mutation that causes it.
Family members of someone diagnosed with hypertrophic cardiomyopathy should consider getting tested. This includes:
- Parents
- Children
- Siblings
Complications
Hypertrophic cardiomyopathy (HCM) can lead to several serious health issues. These complications may develop gradually or appear suddenly.
Irregular Heart Rhythm
Atrial fibrillation (AFib) often occurs in people with HCM. The thickened heart muscle changes how electrical signals move through the heart, causing irregular and sometimes rapid heartbeats.
AFib increases the risk of blood clots forming, which may travel to the brain and cause a stroke.
Obstructed Blood Flow
The thickened heart muscle can block blood from leaving the heart properly. This obstruction may cause:
- Shortness of breath during activity
- Chest pain
- Dizziness
- Fainting episodes
Valve Problems
Blood flow blockage can prevent the mitral valve (between the left heart chambers) from closing correctly. This leads to mitral valve regurgitation, where blood leaks backward into the upper chamber, often worsening symptoms.
Weakened Heart Muscle
A small percentage of HCM patients develop dilated cardiomyopathy. In this condition:
- The thickened heart muscle becomes weak
- The left lower chamber (ventricle) enlarges
- The heart pumps less effectively
Heart Failure
Over time, the heart muscle may become too stiff to fill properly with blood. This prevents the heart from pumping enough blood to meet the body’s needs, resulting in heart failure.
Fainting (Syncope)
Unexplained fainting can occur due to:
- Irregular heart rhythms
- Blocked blood flow to the brain
Fainting episodes, especially in young people, may signal a risk for sudden cardiac death.
Sudden Cardiac Death
Though rare, HCM can cause sudden death at any age. Many people don’t know they have HCM until a serious event occurs. This is particularly concerning for young, active people, including student athletes who appear healthy.
Preventing Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is typically inherited and cannot be prevented. Early detection remains the best approach for managing this condition.
Family Screening Options:
- Genetic Testing – May identify the gene changes that cause HCM.
- Echocardiograms – Use sound waves to create heart images when genetic testing isn’t possible or helpful.
Recommended Screening Schedule for Family Members:
| Age Group | Screening Frequency |
|---|---|
| Age 12 through 18-21 | Every 1-3 years |
| Adults (after age 21) | Every 5 years |
Regular screening is especially important for people with a family history of the condition.
