What arrhythmia may occur with excessive vagal stimulation?

Excessive vagal stimulation can lead to a junctional rhythm, which occurs when the normal electrical conduction pathway is altered due to increased activity of the vagus nerve. This may result in a slower heart rate because vagal stimulation inhibits the sinus node, which is responsible for initiating heartbeats in a normal rhythm.

The junctional rhythm arises when the atrioventricular (AV) node or the junction of atria and ventricles takes over pacing due to this inhibition or failure of the sinus node. This often results in a heart rate that is typically lower than normal, usually between 40-60 beats per minute. The response to vagal stimulation is particularly notable when the heart rate is bradycardic, making junctional rhythm a likely consequence of this condition.

In contrast, other arrhythmias listed do not primarily result from increased vagal tone. Atrial fibrillation, for instance, is characterized by an irregular and often rapid heart rate that is not directly associated with vagal stimulation. Ventricular tachycardia is a much faster and more dangerous arrhythmia usually arising from ectopic activity in the ventricles, while sinus tachycardia represents an increased heart rate that occurs in response to the body’s need