Which cardiac condition involves dysfunction of the cardiac muscle leading to decreased cardiac output?

Cardiomyopathy is characterized by a dysfunction of the cardiac muscle which can lead to decreased cardiac output. The condition affects the heart’s ability to pump blood effectively, resulting in symptoms of heart failure and diminished overall cardiac efficiency.

In cardiomyopathy, the muscle of the heart can become enlarged, thickened, or rigid, which directly impacts the way the heart contracts and fills with blood. This dysfunction can arise from various causes, including genetic predisposition, chronic high blood pressure, and exposure to toxins or infections. The resultant decrease in cardiac output can lead to fatigue, shortness of breath, and fluid retention, as the body's organs are not receiving adequate blood flow necessary for their functioning.

Other conditions like aortic stenosis, mitral insufficiency, and pulmonic lesions are associated with structural issues of the heart valves or outflow tracts, which can lead to heart failure, but they primarily involve obstruction or regurgitation rather than intrinsic dysfunction of the cardiac muscle itself. Thus, while they can also result in decreased cardiac output, they do not originate from the cardiac muscle's inherent dysfunction in the same way that cardiomyopathy does.