Which neuromuscular blocker tends to increase heart rate and mean arterial pressure?

Which neuromuscular blocker tends to increase heart rate and mean arterial pressure?

• A. Decreases heart rate
• B. Increases heart rate and blood pressure
• C. No effect on cardiovascular parameters
• D. Lowers blood pressure

Answer: (B)

The main idea is that some neuromuscular blockers have autonomic effects that alter cardiovascular parameters. The one that tends to increase heart rate and mean arterial pressure does so because it blocks parasympathetic (vagal) influence on the heart. By inhibiting muscarinic receptors in the heart, it removes the normal vagal braking, letting the heart rate rise. The higher heart rate tends to increase cardiac output, which in turn raises mean arterial pressure. This is characteristic of pancuronium, which has notable vagolytic activity. Other agents either cause histamine release and potential hypotension, have minimal cardiovascular effects, or cause only transient tachycardia with less reliable MAP changes.

The main idea is that some neuromuscular blockers have autonomic effects that alter cardiovascular parameters. The one that tends to increase heart rate and mean arterial pressure does so because it blocks parasympathetic (vagal) influence on the heart. By inhibiting muscarinic receptors in the heart, it removes the normal vagal braking, letting the heart rate rise. The higher heart rate tends to increase cardiac output, which in turn raises mean arterial pressure. This is characteristic of pancuronium, which has notable vagolytic activity. Other agents either cause histamine release and potential hypotension, have minimal cardiovascular effects, or cause only transient tachycardia with less reliable MAP changes.