Nuclear left ventriculography at rest and during atrial pacing in the evaluation of coronary artery disease.

This study was undertaken to examine the value of rapid atrial pacing (RAP) combined with left-ventricular nuclear (LVN) angiography in the diagnosis of ischemic heart disease. It included 32 patients: 12 normal subjects and 20 with clinical coronary artery disease (CAD) and greater than 50% narrowing of a coronary artery (significant CAD). The ECG and an LVN angiogram (LVNA) were recorded at rest and during graded RAP. In the normal subjects, left-ventricular wall motion was normal at rest and during atrial pacing, but a wall motion abnormality (WMA) appeared in one subject. Left-ventricular ejection fraction (EF) did not change significantly. In the 20 patients with significant CAD, the diagnostic sensitivity of the ECG during RAP was 100% and 90% for the nuclear angiogram (presence or appearance of WMA at rest and during RAP). The mean EF in this group decreased from 0.38 to 0.31. WMA on the LVNA was present in 79% of patients with significant left-anterior descending, in 44% of those with right, and in 33% of those with circumflex coronary artery disease. WMA (at rest or on pacing) occurred in 17% of patients with 50 to 89% narrowing of an artery, in 50% with 90 to 99% narrowing and in 68% with total obstructions. The LVNA (rest and/or RAP) identified patients with significant single-vessel disease, but underestimated the extent of double-and triple-vessel disease. The LVNA at rest and during atrial pacing was an excellent method of evaluating significant coronary artery disease.