Effects of contrast medium on left ventricular pressure and volume with emphasis on coronary artery disease.

Forty-one patients had left ventricular angiography repeated 3 minutes after an initial study in order to evaluate the effect of angiographic contrast medium on left ventricular end-diastolic pressure (EDP) and volume (EDV). Seven patients had no evidence of heart disease (normal group) and 34 patients had coronary artery disease. Single-vessel diseae was present in 10, double-vessel disease in 10, and triple-vessel disease in 14 patients. Seven other patients with radiopague epicardial clips previously attached to the left ventricle underwent cinefluorographic studies to determine end-diastolic intraclip distance at various intervals after a left ventricular angiogram. In all the groups studied there was a significant increase (p less than 0.005) in both the left ventricular EPD and EDV in the second angiographic study as compared to the first. This increase in EDV (deltaV) was similar in all groups. However, the increase in EDP (deltaP) was significantly greater (p less than 0.01) in patients with double- and triple-vessel disease as compared to the normal and single-vessel disease groups. Ejection fraction, per cent shortening of the heart axis, and contractile pattern in the normal subjects were not singnificantly different when the second angiographic study was compared to the first. In nine of 34 patients with coronary artery disease the second angiographic study demonstrated impairment in left ventricular contractile pattern not present in the first angiographic study. Cinefluorographic study demonstrated an increase in end-diastolic intraclip distance after the left ventricular angiogram. The change in intraclip distance corresponded directionally and temporally to the changes in left ventricular EDP. The present study revealed that the increase in left ventricular end-diastolic press-re associated with the injection of angiographic contrast medium can be explained by an increase in EDV and that such changes last for over 15 minutes and may be associated with alterations in the contractile pattern of the left ventricle.