What is the major cardiac complication risk in DMD?

• A. Aortic stenosis
• B. Pulmonary embolism
• C. Hypertrophic cardiomyopathy
• D. Dilated cardiomyopathy

Answer: (D)

In Duchenne muscular dystrophy, the heart muscle is directly affected by the loss of dystrophin, leading to progressive weakening and damage of the myocardium. The most important and common cardiac complication that results from this is dilated cardiomyopathy, where the heart chambers enlarge and the pumping ability (systolic function) declines. This reduces the ejection fraction and can progress to heart failure, with potential arrhythmias and increased risk of sudden cardiac death.

Other options don’t fit the primary pattern of cardiac disease in DMD: aortic stenosis is a valvular issue not caused by dystrophin deficiency, hypertrophic cardiomyopathy is a separate genetic condition with thickened heart walls rather than dilation, and while pulmonary embolism can occur with immobility, it is not the major cardiac complication intrinsic to DMD.