Florida State Paramedic Practice Exam

What effect does a dromotropic drug have on the heart?

1. Increases blood pressure

2. Alters the rate of contraction

3. Alters velocity of conduction

4. Decreases heart rate

The correct answer is: Alters velocity of conduction

A dromotropic drug specifically affects the conduction velocity within the heart, particularly in the cardiac conduction system such as the atrioventricular (AV) node. By modifying this conduction speed, dromotropic agents can influence how quickly electrical impulses travel through the heart muscle, ultimately impacting the timing of heart contractions. For instance, if a dromotropic drug is employed to enhance conduction velocity, it may lead to a more synchronized heartbeat and improved cardiac output in certain clinical scenarios. Conversely, if the drug decreases conduction velocity, it can protect the heart from excessively rapid rhythms or other conduction abnormalities. Understanding this concept is crucial in the practice of paramedicine, as it helps healthcare providers select appropriate pharmacological interventions based on the patient’s cardiac condition and the desired influence on the heart's electrical activity.