As a medical professional with expertise in cardiology, I can provide insight into the nature of junctional rhythms. A junctional rhythm typically originates from the atrioventricular (AV) node or the nearby tissue. It is generally regular in nature because the AV node has the ability to initiate electrical impulses at a consistent rate. However, there can be exceptions where the rhythm may be irregular if the impulses from the AV node are not consistent, which can occur in a junctional escape complex when the normal sinus rhythm is disrupted and the AV node takes over with varying degrees of success. The appearance of P waves in a junctional rhythm depends on the site of the ectopic focus. If the focus is above the bundle of His, the P wave may be inverted and could appear before, after, or even hidden within the QRS complex. If the focus is below the bundle of His, P waves may not be visible at all because they are superimposed on the QRS complex. read more >>

Rhythm: Irregular in single junctional escape complex; regular in junctional escape rhythm. P waves: Depends on the site of the ectopic focus. They will be inverted, and may appear before or after the QRS complex, or they may be absent, hidden by the QRS.read more >>