Question

_______ increases cardiac output in congestive heart failure without having any direct myocardial action.

• A. \( \text{Amrinone} \)
• B. \( \text{Captopril} \)
• C. \( \text{Digoxin} \)
• D. \( \text{Dobutamine} \)

Hint:

Think of ACE inhibitors like captopril as "helpers" that make it easier for the heart to pump by reducing resistance, rather than directly making the heart muscle stronger.

Answer 1

The Correct Option is B

Captopril is an angiotensin-converting enzyme (ACE) inhibitor. In congestive heart failure, it reduces afterload and preload by inhibiting the renin-angiotensin-aldosterone system, leading to vasodilation and decreased blood volume. This improves cardiac output indirectly without a direct action on the myocardium. Amrinone and dobutamine are positive inotropic agents that directly increase myocardial contractility. Digoxin is also a positive inotrope but its use is more complex and has direct effects on the heart muscle. Captopril's primary mechanism in improving cardiac output in heart failure is by reducing the workload on the heart through vasodilation and reduced fluid retention.