has participant quality atrioventricular block AE first degree atrioventricular block AE 10003674 CTCAE: E10098 NCIt: C62015 SS first degree heart block an atrioventricular block AE that there is some prolongation of AV conduction time (PR interval). The heart's electrical signals are slowed as they move from the atria to the ventricles (the heart's upper and lower chambers, respectively). This results in a longer, flatter line between the P and the R waves on the EKG (electrocardiogram). atrioventricular block first degree WEB: http://www.medilexicon.com/medicaldictionary.php?t=10751 WEB: http://www.nhlbi.nih.gov/health//dci/Diseases/hb/hb_types.html AE severity G1 AE severity G2