Changes in left ventricular diastolic function in coronary artery disease with and without angina pectoris assessed from exercise ventriculography

Abstract

In 11 normals and 43 patients with coronary artery disease left ventricular (LV) diastolic pressure–volume (P–V) curves were obtained from biplane ventriculograms and simultaneous high fidelity pressure measurements. During exercise ventriculography 20 patients had angina pectoris (group B), and 16 patients were asymptomatic (group A). At rest there were no akinetic segments in 28 patients (group C), and an akinetic segment was found in 15 (group D). With different total work loads (951 ± 134 and 2100 ± 245 kpm in groups B and A), LV minimal and end-diastolic pressures and corresponding ventricular volumes increased to a similar extent in patients with and without angina during exercise ventriculography. With comparable work loads (1,296±221 and 1,494±195 kpm in groups C and D) the mean increase in diastolic pressure and volume was larger in group D, which corresponded to the more depressed LV resting function. Shifts in the diastolic P–V relationship with exercise were quantitated from the constants a and b of the linear log P–V relationship. In the control group, a and b did not change significantly, but in all CAD groups a significant decrease in a and a significant increase in b were observed during exercise. These changes were more pronounced in groups B and D, but were statistically significant in group A, too. While no patient with angina had an unchanged diastolic P–V relationship, as many as 12 patients had significant P–V shifts in the absence of angina. Eight of these were expected to develop myocardial ischemia with exercise as judged from their coronary artery stenosis and ventriculograms. A similar correlation was found for the diastolic P–V alterations and the exercise ECG. Fourteen patients without any ST-segment change during exercise showed significant P–V shifts, while no patient with signs of ischemia in the ECG had an unchanged P–V curve. We conclude that LV diastolic function is more sensitive to myocardial ischemia than both angina pectoris and the exercise ECG. An inappropriate increase in LV filling pressure with exercise probably reflects myocardial ischemia even in the absence of angina pectoris and ST-segment depression in the ECG.