Myocardial ischemia after left ventriculography: pathophysiology and clinical significance.

The effects of contrast material on the left ventricular end-diastolic pressure (LVEDP) were evaluated in three groups of patients. Twenty patients (group I) with severe coronary artery disease (CAD) were found to have a change in LVEDP greater than or equal to 20 mm Hg; 15 patients (group II) with severe CAD had elevation of LVEDP less than 20 mm Hg; ten patients (group III) with normal coronary angiograms had a rise in LVEDP less than 20 mM Hg. The change in LVEDP was higher in group I than in groups II and III (P less than 0.005). Nineteen patients (95%) in group I complained of angina pectoris or had ST segment depression (or both) after ventriculography in association with the sharp increment in LVEDP. Angina or ST depression were seen in only two patients (13%) in group II and none in group III. We conclude that 1) elevation of LVEDP of 20 mm Hg or more after ventriculography may be seen in patients with severe CAD (most likely secondary to direct depressant effect of the contrast material on the myocardium) and 2) the abrupt and marked rise in LVEDP may produce myocardial ischemia due to reduction of coronary blood flow, especially to the subendocardial layer.