During heart failure,
A)the Frank-Starling curve shifts to the left
B)the heart pumps out a smaller stroke volume than normal for a given EDV
C)a compensatory increase in sympathetic activity increases the contractility of the heart to normal in the early stages of the disease
D)both a and c occur
E)both b and c occur

Question

Quizplus · Accepted Answer

Heart failure leads to a decrease in cardiac output, resulting in a smaller stroke volume (option B). To compensate for this reduced output, sympathetic activity increases, leading to increased contractility in the early stages of the disease (option C). However, this compensatory mechanism is insufficient in the long run, and the heart gradually loses its ability to compensate. As a result, the Frank-Starling curve shifts to the right, meaning that a greater EDV is required to achieve the same level of cardiac output (option A is incorrect). Thus, options B and C are correct, and the answer is E.

During Heart Failure