Retrograde P wave
Also calledretrograde P · retrograde atrial activation
Definition
A P wave produced by atrial depolarization that travels backward (retrograde) from a junctional or ventricular site up to the atria, usually through the AV node or an accessory pathway, so it is negative (inverted) in the inferior leads II, III, and aVF. Its timing relative to the QRS varies: it may precede the QRS with a short PR interval (below the normal 120 ms), be hidden within the QRS (sometimes visible only as a pseudo-S wave in the inferior leads or a pseudo-R' in V1), or follow it in the ST segment, where the gap from the QRS onset to the P wave is the RP interval.
Sources
- Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia. Circulation. 2016;133(14):e506-e574. doi.org/10.1161/CIR.0000000000000311
- 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.