What is the ECG event that occurs after a sinus pause with no P wave but a wide QRS?

The circumstance described in the question involves a sinus pause followed by a wide QRS complex without a preceding P wave. This scenario is indicative of a ventricular escape beat. When the heart's natural pacemaker, the sinoatrial (SA) node, fails to fire for a period, the ventricles may initiate their own electrical activity to maintain a heartbeat. This self-generated heartbeat is known as an escape beat.

In this case, because there is no P wave preceding the wide QRS complex, it suggests that the impulse is originating from the ventricles rather than the atria. The wide QRS morphology often occurs when the ventricles depolarize abnormally, which is characteristic of a ventricular escape beat.

Understanding the distinction between this and other arrhythmias is critical. Junctional escape beats, for instance, arise from the atrioventricular (AV) junction, which would still typically have a narrow QRS and may or may not have an associated P wave. Accelerated junctional rhythms either do not demonstrate a sinus pause or will show narrow QRS complexes and typically have consistent P waves, which is not the case here. Ventricular tachycardia involves a series of rapid ventricular beats that can also have a wide QRS