A negative chronotropic effect is defined by what physiological change?

A negative chronotropic effect refers to a decrease in heart rate. This physiological change occurs when the influences on the heart, such as hormonal signals or neural input, lead to a slowing of the rhythm of the heartbeat. It can be caused by mechanisms like increased vagal tone or certain medications that slow down the heart's electrical conduction.

In the context of heart physiology, chronotropic effects specifically relate to the rate at which the heart beats. A negative effect in this context clearly indicates that the heart rate is lowered, distinguishing it from positive chronotropic effects which would increase heart rate. The understanding of this term is crucial, especially when studying cardiovascular responses or conditions that can affect heart rate.