[Electrocardiogram and M-mode echocardiography in the diagnosis of chronic transmural infarct. Correlations and determination of the accuracy of both methods based on quantitative levocardiography].
In a comparative study of 121 consecutive patients who had had coronary angiography for coronary heart disease, the diagnostic informations obtained by M-mode echocardiography and electrocardiography in chronic transmural infarction were compared. Wall excursion by echocardiography did not allow sufficient separation of normal and asynergic segments. Changes in systolic wall thickness, on the other hand, provided satisfactory sensitivity and good specificity in the recognition of segmental contraction disorders: posterior wall thickening of 0.64 and 0.76, respectively, septal thickening of 0.45 and 0.91, respectively. In 53% of patients the ECG and echocardiogram provided findings similar to those by angiography. False-positive findings occurred in 10% of electrocardiograms, 14% of echocardiograms. False-negative findings in the ECG occurred in 13%, in the echocardiogram in 25%. Both methods combined had a specificity of nearly 100% with regard to the diagnosis of posterior-wall and anterior-wall infarction, and a positive predictive value of 0.92 (posterior) and 0.93 (anterior wall infarction). M-mode echocardiography and ECG findings provide reliable diagnosis of both the anterior and posterior wall chronic transmural infarction.