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Effects of coronary arteriography on atrioventricular conduction. Studies with His bundle electrography
Insights
Coronary arteriography temporarily slows atrioventricular (A-V) conduction by prolonging the A-H interval. This effect appears to be osmotic, not due to reduced blood flow, as contrast agents and hypertonic glucose caused similar conduction delays.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Coronary arteriography is a common diagnostic procedure.
- Potential effects on cardiac conduction are not fully understood.
Purpose of the Study:
- To investigate the impact of coronary arteriography on atrioventricular (A-V) conduction.
Main Methods:
- Utilized His bundle electrography in 26 patients undergoing coronary arteriography.
- Measured A-H and H-V intervals before, during, and after contrast injection.
- Administered saline and hypertonic glucose as controls.
Main Results:
- All patients showed a prolonged A-H interval post-arteriography.
- The effect was linked to contrast injection into specific coronary arteries.
- Hypertonic glucose mimicked the A-V conduction slowing effect.
Conclusions:
- Coronary arteriography transiently impairs A-V conduction.
- The primary mechanism is likely an osmotic effect from contrast agents, not hypoxia.
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.