[Evaluation of poor R wave progression by cross-sectional echocardiography with wall motion index].

Poor R wave progression (PRWP) in the precordial leads on the electrocardiogram in an often used but ill-defined electrocardiographic finding of antero-septal myocardial infarction. In view of the fact that the cross-sectional echocardiogram (CSE) provides a reliable method for detecting the presence and location of regional asynergy associated with acute myocardial infarction, 47 patients (myocardial infarction; 27, other disease; 20) with PRWP were selected to investigate whether or not CSE could be useful for differentiating the cases showing PRWP with myocardial infarction from those without myocardial infarction. On CSE, the left ventricle was divided into 9 segments, and to grade the severity of segmental asynergy, each segment was assigned a numerical score based upon the type of wall motion. These scores were assigned as follows; hyperkinesis: -1, normal: 0, hypokinesis: +1, akin sis: +2, and dyskinesis: +3 (Heger, 1979). The total wall motion index (WMI) was obtained by summing the scores for each of the 9 segments. And the antero-septal WMI was also obtained by summing the scores for each of the antero-septal segments. The antero-septal WMI in patients with myocardial infarction (4.45 +/- 2.59) was significantly greater than that in patients with other diseases (-0.1 +/- 2.38) (p less than 0.001). The antero-septal WMI equal to or more than +3 was found to be the most useful parameter in identifying the cases with myocardial infarction (sensitivity: 81.5%, specificity: 85.0%). Consequently, it can be concluded that CSE is quite useful for differentiation of PRWP between the cases with or without myocardial infarction.