In hypertrophic cardiomyopathy (HCM)

In hypertrophic cardiomyopathy (HCM)

In hypertrophic cardiomyopathy (HCM), a subtype of diastolic dysfunction commonly seen is known as “Restrictive Diastolic Dysfunction” or “Grade 3 Diastolic Dysfunction.” HCM is a genetic heart disease characterized by abnormal thickening (hypertrophy) of the heart muscle, particularly the left ventricle, without an obvious cause such as high blood pressure or valvular disease.

In HCM, the thickening of the heart muscle can lead to impaired relaxation and filling of the left ventricle during diastole, resulting in restrictive diastolic dysfunction. Some key features of restrictive diastolic dysfunction in HCM include:

  1. Impaired Relaxation and Compliance: The thickened and stiffened left ventricle in HCM has reduced compliance, making it difficult for the ventricle to relax and fill with blood during diastole. This leads to elevated pressures in the left atrium and pulmonary veins.
  2. Elevated Filling Pressures: The impaired relaxation and reduced compliance of the left ventricle result in increased filling pressures during diastole. This can lead to elevated left atrial pressures, pulmonary congestion, and symptoms such as dyspnea (shortness of breath) and fatigue.
  3. Echocardiographic Findings: Echocardiography is the primary imaging modality used to assess diastolic function in HCM. In restrictive diastolic dysfunction, echocardiographic findings may include a restrictive filling pattern on Doppler echocardiography, characterized by rapid early filling (E-wave) and reduced or absent late filling (A-wave). Additionally, tissue Doppler imaging may show reduced early diastolic mitral annular velocity (e’).
  4. Clinical Implications: Restrictive diastolic dysfunction in HCM can contribute to symptoms such as dyspnea, fatigue, and exercise intolerance. It is associated with an increased risk of adverse outcomes, including heart failure, arrhythmias, and sudden cardiac death. Management of restrictive diastolic dysfunction in HCM focuses on optimizing heart rate control, reducing ventricular outflow tract obstruction (if present), and addressing symptoms and complications associated with heart failure.

Overall, restrictive diastolic dysfunction is a common subtype of diastolic dysfunction seen in hypertrophic cardiomyopathy, characterized by impaired relaxation and compliance of the left ventricle, leading to elevated filling pressures and symptoms of heart failure. Early recognition and management of diastolic dysfunction in HCM are essential in improving outcomes and preventing disease progression.