Localization of the conduction delay occurring during coronary arteriography.

The effect of coronary arteriography on intraventricular conduction was studied in 12 atropinized, open-chest dogs. Left bundle-branch (LB) and cavitary (V) potentials were recorded from a bipolar electrode catheter positioned against the septum below the aortic valve. Subendocardial (SEE) and subepicardial (IME) bipolar potentials were obtained from distal and proximal poles of multipolar electrode needles. Conduction times from LB to V, LB or V to SEE and SEE to IME were obtained during control and during Renografin 76 (REN) and normal saline injections into the left and right coronary arteries. Significant QRS axis changes and increased QRS duration occurred in 6 of 12 dogs simultaneously with LB-SEE and V-SEE delay. In 6 without axis changes, REN produced significant delay and increased QRS duration. Only REN to LCA produced significant changes. Coronary arteriography alters conduction through the distal left ventricular Purkinje system without affecting transmural conduction.