Which condition is characterized by thickened heart walls and impaired relaxation?

Hypertrophic cardiomyopathy (HCM) is characterized by thickened heart walls, particularly the ventricles, which leads to impaired relaxation of the heart muscle. This condition often results from genetic mutations that affect the proteins responsible for heart muscle contraction, causing the heart muscle to become abnormally thickened. The thicker walls can diastolic dysfunction, as the heart struggles to relax and fill properly with blood between beats.

In HCM, this impaired relaxation can cause symptoms such as shortness of breath, chest pain, or fainting, especially during physical exertion. Diagnosis is typically made through imaging studies, such as echocardiography, which can visualize the characteristic thickening of the heart walls.

In contrast, dilated cardiomyopathy (DCM) is primarily characterized by the dilation of the heart chambers and impaired systolic function, not by thickened walls. Myocardial infarction involves the death of heart muscle tissue due to lack of blood flow, which does not specifically lead to the thickening of the walls. Lastly, a ventricular septal defect is a congenital condition resulting in an abnormal opening between the ventricles, leading to shunted blood flow, rather than a direct alteration in wall thickness or relaxation capacity.