Toru Kanaya

Noninvasive assessment of left ventricular wall motion abnormalities by QRS isointegral maps in previous anterior infarction

In order to determine to what extent left ventriculographic abnormalities can be predicted from ECG changes in myocardial infarction (MI), 87 unipolar ECGs were simultaneously recorded in 22 patients with previous anterior MI with no conduction defects. We adopted a QRS isointegral mapping technique for analyzing body surface mapping data. Particular attention was given to the area where the QRS time-integral value was less than the lower limit (mean minus two standard deviations) of the normal, and this area was designated as the departure area. Left ventricular wall motion was assessed by left ventriculography and correlated with the departure area. The departure area demonstrated a close correlation with the left ventricular ejection fraction (r = -0.93) and the extent of asynergy (r = 0.74). It is suggested that the departure area reflects the loss of electromotive force due to MI. We conclude from this study that the QRS isointegral map is a useful method for evaluating left ventricular function in patients with anterior MI.