Final answer:
A junctional rhythm can be caused by an ectopic focus or ectopic pacemaker, which can result from localized ischemia, exposure to drugs, or elevated stimulation by the autonomic nervous system. In chronic cases, an artificial pacemaker may be used to restore full sinus rhythm.
Step-by-step explanation:
A common cause of a junctional rhythm is an ectopic focus or ectopic pacemaker, which can be stimulated by localized ischemia, exposure to certain drugs, or elevated stimulation by the autonomic nervous system. This can lead to an arrhythmia, a deviation from the normal pattern of impulse conduction and contraction, or to fibrillation, an uncoordinated beating of the heart.
In some cases, when arrhythmias become chronic, the heart maintains a junctional rhythm that originates in the atrioventricular (AV) node. In these cases, a cardiologist may implant an artificial pacemaker to restore full sinus rhythm and ensure proper heart contraction and blood pumping.