Dromotropic refers to which aspect of cardiac function?

Dromotropic refers to which aspect of cardiac function?

• A. Chronotropic
• B. Inotropic
• C. Dromotropic
• D. Lusitropic

Answer: (C)

Dromotropic refers to the speed of electrical conduction through the AV node from the atria to the ventricles. It describes how quickly impulses travel, which affects how quickly the ventricles are activated after atrial depolarization. This is why dromotropy is linked to the PR interval on an ECG: faster AV nodal conduction shortens the interval, slower conduction lengthens it. This concept is distinct from chronotropic effects, which change heart rate; inotropic effects, which change the force of contraction; and lusitropic effects, which change the rate of relaxation. In practice, sympathetic stimulation tends to increase dromotropy (faster AV conduction), while parasympathetic (vagal) activity decreases it (slower AV conduction).

Dromotropic refers to the speed of electrical conduction through the AV node from the atria to the ventricles. It describes how quickly impulses travel, which affects how quickly the ventricles are activated after atrial depolarization. This is why dromotropy is linked to the PR interval on an ECG: faster AV nodal conduction shortens the interval, slower conduction lengthens it. This concept is distinct from chronotropic effects, which change heart rate; inotropic effects, which change the force of contraction; and lusitropic effects, which change the rate of relaxation. In practice, sympathetic stimulation tends to increase dromotropy (faster AV conduction), while parasympathetic (vagal) activity decreases it (slower AV conduction).