Escape beat
Also calledescape complex · subsidiary pacemaker beat
Definition
A beat from a subsidiary (latent) pacemaker outside the sinus node that fires only after an expected sinus impulse fails to form or fails to reach the ventricles, so it arrives LATE rather than early (the defining contrast with a premature beat, although both are ectopic in origin). The escape rate reflects the site: junctional escape typically runs at 40 to 60 bpm with a narrow QRS similar to the sinus beats and an absent or retrograde (inverted inferior) P wave, while ventricular escape typically runs at 20 to 40 bpm with a wide QRS. Escape beats are a backup mechanism that appears during sinus arrest or marked sinus slowing, or when AV block stops sinus impulses from reaching the ventricles.
Sources
- Ashkanani AA, Ashkanani AH, Alkandari MF, et al. An accessible algorithm for the quick and precise interpretation of atrioventricular blocks in electrocardiograms. Ann Noninvasive Electrocardiol. 2026;31(4):e70207. doi.org/10.1111/anec.70207
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
- Antzelevitch C, Burashnikov A. Overview of basic mechanisms of cardiac arrhythmia. Card Electrophysiol Clin. 2011;3(1):23-45. doi.org/10.1016/j.ccep.2010.10.012
- Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay. Circulation. 2019;140(8):e382-e482. doi.org/10.1161/CIR.0000000000000628
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.