What is the hemodynamic effect of IV vasodilators in acute decompensated heart failure?

• A. It reduces preload and afterload
• B. It increases preload to improve renal perfusion
• C. It has no effect on hemodynamics
• D. It worsens edema

Answer: (A)

In acute decompensated heart failure, IV vasodilators relieve congestion by lowering both the pressures the heart must work against and the amount of blood returning to the heart. They cause venous dilation, which reduces preload, and arterial dilation, which lowers afterload. The result is a drop in left ventricular filling pressures (lowered preload) and systemic vascular resistance (lowered afterload), leading to improved forward output and less pulmonary edema. This is why symptoms like dyspnea and edema improve with these agents. They do not increase preload or have no hemodynamic effect; they also do not worsen edema—quite the opposite.