In which condition does the atrial muscle thin and the chamber weakens over time?

The condition described is cardiomyopathy dilation. In dilated cardiomyopathy, the heart's chambers, particularly the atria, become enlarged and the muscle wall thins. This weakening and stretching of the heart muscle impair its ability to pump blood effectively. Over time, as the condition progresses, the atrial muscle can thin, which leads to a decline in the structural integrity of the heart.

This condition may arise from various factors, including genetic predispositions, chronic alcohol abuse, or viral infections that affect heart tissue. The dilation of the chambers can also lead to arrhythmias and heart failure because the weakened muscle is less capable of responding effectively to the body’s demands for blood circulation. Understanding how dilated cardiomyopathy affects the heart’s anatomy helps in recognizing its implications for overall cardiovascular health.