Ventricular escape beat
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
A ventricular escape beat is a heart rhythm finding, discovered on EKG, that indicates the normal electrical conduction system of the heart is disrupted or performing inadequately.
More specifically, it is an ectopic beat that occurs after an extended pause in a rhythm, indicating either the failure of the SA node to initiate a beat or the failure of the conduction of this beat to the AV node. While the SA node typically initiates a rate of 70 beats per minute (BPM), the AV node is usually only capable of generating a rhythm at 40-60 BPM. If the AV node does not receive a signal from the SA node after a second or two, the AV node's pacemaking activity kicks in (as a safety mechanism), and attempts to set the rate around 40 BPM.
If there are only one or two ectopic beats, they are considered escape beats. If this causes a semi-normal rhythm to arise it is considered an idioventricular rhythm.
The escape arrhythmia is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system (commonly due to heart attack or medication side effect) , and because of its low rate, it can cause a drop in blood pressure.
An escape rhythm may develop if another pacemaker takes over.