Which condition describes a situation where the heart muscle becomes abnormally thick?

The condition where the heart muscle becomes abnormally thick is referred to as hypertrophic cardiomyopathy. This condition results in an increase in the size of the cardiac muscle, particularly in the ventricles, which can affect the heart's ability to pump blood effectively. The thickening often occurs in the left ventricle, and it can lead to various complications, including arrhythmias, heart failure, and sudden cardiac arrest in severe cases.

Hypertrophic cardiomyopathy is distinct from other forms of cardiomyopathy, such as dilated cardiomyopathy, where the heart muscle is weakened and enlarged rather than thickened. Coronary artery disease pertains to the narrowing or blockage of coronary arteries, which primarily affects blood flow rather than the thickness of the heart muscle itself. Myocardial ischemia describes a state where the heart muscle does not receive enough blood and oxygen, but this condition is more about the supply issue rather than the structural change of the heart muscle itself. Thus, the correct choice accurately identifies the condition associated with the thickening of the heart muscle.