second degree atrioventricular block Mobitz I atrioventricular block 2026-07-20T13:04:51Z Wenckebach phenomenon a type of second-degree atrioventricular block characterized by P waves exhibiting a consistent rate and a gradual prolongation of the PR interval; this is followed by periodic occurrences of single non-conducted P waves, typically accompanied by P waves preceding and following the non-conducted P waves Mobitz type I second-degree AV block 2nd-degree, Mobitz I AV block Mobitz I AV block Mobitz I is usually due to reversible conduction block at the level of the AV node. It is usually a benign rhythm, causing minimal hemodynamic disturbance and with low risk of progression to third-degree heart block. MPheno.ontology MP:0031760 Mobitz type 1 atrioventricular block Wenckebach block