Which compensatory mechanism for CHF involves the heart muscle stretching to increase contractility?

The correct answer relates to the physiological response of dilation, which refers to the enlargement of the heart's chambers, particularly the ventricles, as they fill with more blood. In the context of congestive heart failure (CHF), this dilation occurs as a compensatory mechanism to help increase the heart's ability to pump blood more effectively. When the heart muscle stretches, it enhances the force of contraction due to the Frank-Starling mechanism—this principle states that the more the heart muscle fibers are stretched (up to a certain point), the stronger they contract.

This dilation allows the heart to accommodate a larger volume of blood, which can improve cardiac output. While hypertrophy, or the thickening of the heart muscle, is another adaptive response to increased workload, it primarily increases muscle mass rather than the chamber size. Stimulation of the sympathetic nervous system (SNS) serves to increase heart rate and contractility but does not involve stretching of the muscle for enhanced contractility. Vasodilation refers to the widening of blood vessels to reduce resistance to blood flow, which does not specifically relate to the heart muscle's contractility mechanisms.

Understanding these mechanisms is crucial for effectively managing CHF, as they inform treatment strategies aimed at improving cardiac function and alleviating symptoms.