Objective measurement of changes in regional wall motion characteristics following coronary artery bypass grafting...

Difficulties arise when using non-invasive methods to measure changes in regional left ventricular function. With the increasing recognition of the entity of hibernating myocardium, and the known asymmetric effects of coronary artery disease, this is an important problem, as it prevents detailed investigation of the effects of revascularization upon ventricular function. We investigated the use of tomographic radionuclide ventriculography in assessing such changes. Twenty consecutive patients (18 males, 2 females, mean age 60 years), undergoing elective coronary artery bypass surgery, were identified and imaged prior to and after surgery. The mean global left ventricular ejection fraction was 42 and 45% pre- and post-surgery, respectively. Following revascularization, it was improved in 9 patients, unchanged in 3 and deteriorated in 8. By comparison with pooled normal data from 25 subjects, 10 patients were noted to have overall resting phase values within normal limits. After surgery, an improvement was seen in 5 patients, no significant change in 11 and a deterioration in 4. With respect to regional ejection fraction, 24 of 80 segments improved, 25 remained unchanged and 31 deteriorated. For regional phase analysis, 26 improved, 45 remained unchanged and 9 deteriorated. confirmed that important regional changes in left ventricular function occur following revascularization, even without a change in global ejection fraction.