Afterload reduction is beneficial during anesthesia for noncardiac surgery in patients with each of the following conditions EXCEPT

Afterload reduction is beneficial during anesthesia for noncardiac surgery in patients with each of the following conditions EXCEPT

• A. Aortic insufficiency
• B. Mitral regurgitation
• C. Tetralogy of Fallot
• D. Congestive heart failure

Answer: (C)

Lowering systemic afterload during anesthesia tends to help conditions where the heart’s regurgitation is the major problem or where reduced wall stress and easier forward flow improve overall cardiac output. In aortic insufficiency and mitral regurgitation, decreasing afterload reduces the regurgitant volume and the ventricle’s workload, helping forward flow. In congestive heart failure, less afterload decreases myocardial wall stress and can improve stroke work and oxygen delivery. The exception is Tetralogy of Fallot. This condition features a fixed right ventricular outflow tract obstruction with a ventricular septal defect, creating a right-to-left shunt. Reducing afterload lowers systemic vascular resistance, which shifts pressures in a way that worsens the right-to-left shunt and decreases arterial oxygen saturation. Maintaining or even increasing SVR is often desirable to limit shunting and improve oxygenation.

Lowering systemic afterload during anesthesia tends to help conditions where the heart’s regurgitation is the major problem or where reduced wall stress and easier forward flow improve overall cardiac output. In aortic insufficiency and mitral regurgitation, decreasing afterload reduces the regurgitant volume and the ventricle’s workload, helping forward flow. In congestive heart failure, less afterload decreases myocardial wall stress and can improve stroke work and oxygen delivery.

The exception is Tetralogy of Fallot. This condition features a fixed right ventricular outflow tract obstruction with a ventricular septal defect, creating a right-to-left shunt. Reducing afterload lowers systemic vascular resistance, which shifts pressures in a way that worsens the right-to-left shunt and decreases arterial oxygen saturation. Maintaining or even increasing SVR is often desirable to limit shunting and improve oxygenation.