title: Effects of coronary arteriography on atrioventricular conduction. Studies with His bundle electrography.
abstract: The effect of coronary arteriography on atrioventricular (A-V) conduction was studied in 26 patients with the use of His bundle electrography. Slowing of atrioventricular conduction (prolonged A-H interval) was observed in all 26 pateints following either left or right coronary arteriography without a detectable change in the H-V interval. In four patients with left coronary preponderance in arterial distribution pattern, prolonged A-H inverval was produced only by injecting the contrast material into the left coronary artery. Conversely, in the remaining 22 patiens either with right preponderance or balanced distribution, prolongation of the A-H time was a result of opacification of the right coronary artery. The A-H interval at peak prolongation (133.9 +/- 18.7 [S.D.] msec.) was significantly higher than the control measurement (98.3 +/- 15.7 msec.) (P less than 0.0001). Prolongation of the A-H interval started around 4 seconds after the initiation of injection, reached its peak at an average of 7.7 seconds, and subsided within 20 seconds. When intracoronary injection of 6 ml. of normal saline was made in these 26 patients, no change was observed in the His bundle electrograms. On the other hand, hypertonic (20 per cent) glucose solution, when injected into coronary arteries, had an effect remearably similar to  that of contrast material on A-V conduction. These findings suggest that prolonged A-H interval observed during coronary arteriography may be a result of osmotic effect of the contrast material, rather than hypoxia resulting from dilution of coronary blood flow.
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000009:adverse effects*; D002036:Bundle of His / Q000187:drug effects; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D003973:Diatrizoate / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005947:Glucose / Q000009:adverse effects; D006329:Heart Conduction System / Q000187:drug effects; D006801:Humans; D006982:Hypertonic Solutions / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D012965:Sodium Chloride / Q000009:adverse effects
chemical_list: D006982:Hypertonic Solutions; D003973:Diatrizoate; D012965:Sodium Chloride; D005947:Glucose