Non-invasive quantification of exercise-induced changes in regional left ventricular function in normals and patients with one vessel coronary artery disease using radionuclide ventriculography

To quantitate changes in regional left ventricular functioninduced by ischemia or scar, rest and exercise equilibrium radionuclidestudies of 26 patients with one vessel coronary artery diseaseand 12 normal individuals were analysed with a new method forregional ejection fraction determination. A computer algorithmprovided observer-independent segmental analysis from a centreof gravity of the left ventricular activity at end-diastole(left anterior oblique projection). Special segments were assignedfor anteroseptal, inferoapical and posterolateral areas correspondingto the three main coronary arteries. Reproducibility using anunchanged camera positioning was excellent even for 2 min acquisitionstudies (r=0.93) and still good after repositioning (r=0.80to 0.87). In normal areas, regional ejection fraction increasedor showed no change during exercise. In contrast, it decreasedsignificantly in regions supplied by stenosed coronary arteries(ischemia) and remained depressed in scar zones. The methodproved to be valid for regional changes induced by left anteriordescending and left circumflex coronary obstructions, but lessfor right coronary artery lesions. Global ejection fractionreflected a sum of all regional changes implying that regionalanalysis should be more sensitive in detecting coronary arterydisease.