Second degree atrioventricular block Mobitz I atrioventricular block 2012-04-11T07:25:17Z HP:0011707 Wenckebach block Mobitz I atrioventricular block is associated with a normal QRS duration. SNOMEDCT_US:54016002 Mobitz type 1 atrioventricular block UMLS:C0264907 Progressive PR interval prolongation with the subsequent occurrence of a single nonconducted P wave that results in a pause. The pause that follows the nonconducted impulse is less than fully compensatory (less than the sum of two normal sinus intervals).