Source:http://linkedlifedata.com/resource/umls/id/C0004245
MSH: Impaired impulse conduction from HEART ATRIA to HEART VENTRICLES. AV block can mean delayed or completely blocked impulse conduction.,NCI: A delay or failure in the conduction of a cardiac impulse from the atria to the ventricles at the level of the atrioventricular node.