Septal Q wave in exercise testing: evaluation by single photon-emission computed tomography before and after coronary bypass grafting

ABSTRACT

To evaluate changes of septal Q waves in lead V5 by exercise with single-photon emission computed tomography [SPELT], seven patients were studied before and after coronary artery bypass grafting [CABG]. Multivessel coronary artery disease was present in all of them. In rive patients there was regression of Q wave amplitude during exercise [1.4 +/- 0.42 to 0.6 +/- 0.29, P <0.001] and they showed septal perfusion defects by exercise which disappeared in late images. All five had left anterior descending coronary artery [LAD] involvement. Two patients did not show any changes in Q wave amplitude and no septa] ischaemia was seen during stress imaging in them. After CABG, there was no change in the Q wave amplitude during exercise and stress thallium imaging did not show the septal perfusion defects seen preoperatively in the five patients. In all of them, the grafts to LAD were patent. Thus, SPELT before and after CABG during exercise revealed that septal Q waves are valuable in assessing the degree of septal ischaemia