Paced rhythm
Also calledPaced · Paced beat · Electronic pacing · Pacemaker rhythm · Ventricular paced rhythm · Atrial paced rhythm
Definition
A cardiac rhythm generated or triggered by an implanted electronic pacemaker rather than the heart's own conduction system, recognized on the ECG by pacemaker spikes followed by depolarization of the paced chamber. Atrial pacing produces a spike followed by a P wave, whereas ventricular pacing produces a spike followed by a broad QRS (often more than 120 ms) because activation spreads slowly from the pacing site through ventricular muscle. Right ventricular apical pacing typically gives a left bundle branch block pattern with a superior frontal axis.
Clinical notePacing from the right ventricular high septum or outflow tract gives an inferior axis instead.
Sources
- Tan K, Ng S, Foo D, et al. Physiological pacing: just a lot of buzz or the next paradigm shift in bradycardia pacing? Singapore Med J. 2026;67(2):85-89. doi.org/10.4103/singaporemedj.SMJ-2023-067
- Safavi-Naeini P, Saeed M. Pacemaker troubleshooting: common clinical scenarios. Tex Heart Inst J. 2016;43(5):415-418. doi.org/10.14503/THIJ-16-5918
- 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
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.