Dromotropi

Dromotropi refers to the property of a substance, particularly a drug, to affect the speed of conduction of an impulse through a specific tissue. This term is most commonly applied in pharmacology to describe the effects of drugs on the heart. Specifically, dromotropi relates to how a drug influences the conduction velocity through the atrioventricular (AV) node and the His-Purkinje system, which are crucial for coordinating the electrical signals that trigger heartbeats.

Drugs can be classified as positive, negative, or neutral in their dromotropic effects. A positive dromotropic agent increases the speed of conduction. For instance, some sympathetic nervous system stimulants can have a positive dromotropic effect, leading to a faster heart rate by speeding up the transmission of electrical impulses. Conversely, a negative dromotropic agent slows down the conduction velocity. Beta-blockers and calcium channel blockers are classic examples of negative dromotropic drugs. They are often used to treat conditions like supraventricular tachycardia or to control the ventricular rate in atrial fibrillation by reducing the speed at which impulses travel through the AV node. A neutral dromotropic agent has no significant effect on conduction velocity.

Understanding the dromotropic properties of a drug is essential for its safe and effective use, particularly in managing cardiac arrhythmias and other cardiovascular conditions. The effect on conduction speed can have significant implications for heart rate, rhythm, and overall cardiac function.