Hypertrophic Obstructive Cardiomyopathy

Hypertrophic obstructive cardiomyopathy (HOCM) is a subtype of hypertrophic cardiomyopathy (HCM) characterized by the abnormal thickening of the heart muscle, especially in the left ventricle, leading to obstruction of blood flow out of the heart.

 

Types

Hypertrophic obstructive cardiomyopathy is a subtype of hypertrophic cardiomyopathy (HCM). There are different types of HCM based on the distribution of the heart muscle thickening, but HOCM is primarily characterized by the presence of significant obstruction to blood flow from the left ventricle to the aorta, which is a key feature of this condition.

 

Causes

Like hypertrophic cardiomyopathy (HCM), hypertrophic obstructive cardiomyopathy is primarily a genetic disorder caused by mutations in genes that control the proteins responsible for the heart’s contraction and relaxation. These mutations lead to the abnormal growth and arrangement of heart muscle cells, resulting in hypertrophy. HOCM is usually inherited in an autosomal dominant pattern, meaning that a child has a 50% chance of inheriting the mutation if one of their parents carries the abnormal gene.

 

Symptoms

The symptoms of hypertrophic obstructive cardiomyopathy can vary from mild to severe and may include:

  • Shortness of breath, especially during physical activity or lying flat
  • Chest pain or discomfort (angina)
  • Heart palpitations or rapid heartbeat (arrhythmias)
  • Fatigue or weakness, particularly during exercise
  • Dizziness or lightheadedness
  • Fainting or near-fainting episodes (syncope)

Symptoms may worsen during strenuous exercise or activities that increase the heart’s workload.

 

Risk Factors

The risk factors for hypertrophic obstructive cardiomyopathy are similar to those of hypertrophic cardiomyopathy and include:

  • Family history of HCM or sudden cardiac death
  • Presence of specific genetic mutations associated with HCM
  • Age (HCM can be present at birth but may not manifest until later in life)
  • High blood pressure (hypertension)
  • Strenuous exercise or intense physical activity

 

Diagnosis

The diagnosis of hypertrophic obstructive cardiomyopathy involves a comprehensive evaluation, including:

  • Medical history and physical examination: The physician will inquire about symptoms, family history, and perform a thorough physical examination, including listening for a heart murmur.
  • Electrocardiogram (ECG or EKG): This test records the electrical activity of the heart and may show characteristic changes in individuals with HOCM.
  • Echocardiography: This ultrasound test provides detailed images of the heart, allowing visualization of the heart muscle thickness and the presence and severity of the obstruction.
  • Cardiac MRI: This imaging test can provide more detailed information about the heart’s structure and function, particularly in cases where echocardiography is inconclusive.
  • Exercise stress test: In some cases, an exercise stress test may be performed to assess symptoms during physical activity.

 

Treatment

The treatment of hypertrophic obstructive cardiomyopathy aims to manage symptoms, reduce complications, and improve the overall quality of life. Treatment options may include:

  • Medications: Beta-blockers or calcium channel blockers may be prescribed to slow the heart rate and improve relaxation of the heart muscle, reducing symptoms such as chest pain and shortness of breath.
  • Septal myectomy: In severe cases with significant obstruction to blood flow, surgical intervention may be necessary to remove part of the thickened septum, improving blood flow out of the heart.
  • Alcohol septal ablation: This minimally invasive procedure involves injecting alcohol into a specific artery to selectively reduce the thickened heart muscle and improve blood flow.
  • Implantable cardioverter-defibrillator (ICD): In individuals at high risk of life-threatening arrhythmias or sudden cardiac death, an ICD may be implanted to monitor and correct abnormal heart rhythms.
  • Lifestyle modifications: Individuals with HOCM are often advised to avoid strenuous physical activity and competitive sports.

 

When to Consult a Physician

If you or someone you know experiences symptoms such as shortness of breath, chest pain, fainting, or heart palpitations, it is essential to consult a physician for evaluation. Additionally, if there is a family history of hypertrophic obstructive cardiomyopathy or sudden cardiac death, it is crucial to seek medical attention and consider genetic testing and screening for the condition. Early diagnosis and appropriate management are essential to prevent complications and improve long-term outcomes in individuals with HOCM.