Serial Changes in Regional Diastolic Left Ventricular Function After a First Acute Myocardial Infraction

After acute myocardial infarction (AMI), regional diastolic function may be abnormal even though regional systolic function appears normal. However, it is not known whether this represents a transient or permanent phenomenon, and the relation to myocardial viability is not known. To determine this we assessed regional left ventricular function during contraction and filling after AMI in 106 patients with a first AMI. Echocardiography with color kinesis was performed on day 1 and 1, 3, and 6 months after AMI. For both left ventricular systole and diastole the percentage of segments with abnormal wall motion was calculated. During the first 6 months, the area of diastolic wall-motion abnormality decreased (38 ± 16%-30 ± 27%, P = .001) whereas no overall change in area of systolic wall-motion abnormality was seen (18 ± 15%-19 ± 19%, P = .66). However, for patients with no viable myocardium no significant change in diastolic wall-motion abnormality occurred (baseline 45 ± 12% vs 44 ± 27% at 6 months, P = .93). In contrast, a significant decrease was seen for patients with viability (33 ± 16%-22 ± 23%, P < .001). This was almost exclusively caused by normalization of regions where only diastolic wall-motion abnormalities were present (19 ± 11%-7 ± 15%, P < .0001). In a multivariable regression model, myocardial viability (P = .01) and N-terminal pro-brain natriuretic peptide concentration on day 3 (P = .003) were associated with changes in regional diastolic wall-motion abnormalities. Thus, abnormal diastolic wall motion during diastole is frequently present after AMI, and it seems to resolve to a greater extent than abnormal systolic wall-motion abnormality especially for patients with myocardial viability. This suggests diastolic stunning.