Estimation of left ventricular ejection fraction with healed myocardial infarction by multiple regression analysis of...

The cardiac damage caused by a myocardial infarction may be evidenced by abnormal electrocardiographic Q-QS complexes (i.e., Minnesota Q-QS codes) and by impairment of left ventricular function. It has been shown that the level of significance of the Q-QS codes is highly correlated with the extent of left ventricular impairment. This study was directed to quantitating this relationship in subjects with a healed myocardial infarction and expressing it mathematically. Using multiple linear regression analysis, a coefficient value was obtained corresponding to the level of significance of each Q-QS code located in each electrocardiographic cardiac area. The left ventricular ejection fraction was estimated by subtracting the coefficient of the most significant code present in each cardiac area from the constant, which was calculated to be the ejection fraction in the absence of any Q-QS code. The results were reproducible, and there was a good correlation between the estimated and measured ejection fraction.