Mobitz I heart block /mō″bits/ [Woldemar Mobitz, German physician, 1889–1951; AS, hoerte, heart; Fr, bloc, block] , second-degree or partial atrioventricular (AV) block in which the P-R interval increases progressively until the propagation of an atrial impulse to the ventricles does not occur. Mobitz I heart block is caused by abnormal conduction of the cardiac impulse in the AV node and may be precipitated by increased vagal tone, AV nodal ischemia, or digitalis therapy. It may be a complication of inferior myocardial infarction. Also called type I AV block, Wenckebach heart block.
