Cardiac Conduction Abnormalities during Coronary Arteriography in Dogs: Reduced Effects of a New Contrast Medium

Abstract

Cardiac arrhythmias induced by radiopaque agents are complications which follow coronary angiography. A conduction delay through various parts of the heart is one factor in the genesis of arrhythmias. Studies on conduction times through the AV nodal tissues by bipolar His bundle electrograms and through the distal part of the conduction system by recording the QRS complex from the ECG have been examined during the injection of various contrast media and hyperosmotic solutions into the left coronary artery. This investigation demonstrates that metrizamide, a new nonionic contrast agent, causes less effect on the conduction lime through the proximal part of the conduction system than either diatrizoate or metrizoate. Hyperosmolarity is one factor in producing these conduction abnormalities, but the ionic composition of the injected solution is also important.