ALTERATIONS IN THE MITRAL FLOW VELOCITY PATTERN INDUCED BY ACUTE MYOCARDIAL-INFARCTION - DOPPLER FINDINGS BEFORE AND AFTER INFARCTION

Several studies have demonstrated that myocardial infarction (MI) is l ikely to alter left ventricular diastolic function. However, it is unc lear whether MI per se alters Doppler transmitral now velocity pattern s (TMF) clinically. To investigate how myocardial infarction alters TM F clinically, we assessed serial changes in TMF in 13 patients whose T MF patterns were recorded at a mean of 7 months before and after MI in relation to the size of MI. From TMF, early and atrial filling now ve locities (E and A (m/s), respectively), and the E/A ratio, were measur ed. From simultaneously recorded two-dimensional echocardiograms, left ventricular dimensions and wall motion score (WMS: sum of 17 segmenta l scores (dys/akinesis=3 to normal=0)) were determined. The patients w ere divided into two subsets based on the values for WMS in the conval escent stage; 8 patients had small MI (WMS less than or equal to 10) a nd 5 patients had large MI (WMS>10). In patients with small MI, althou gh E and the E/A ratio decreased at day-1 compared with pre-MI values (pre-MI vs day-1, E; 0.54 +/- 0.12 vs 0.39 +/- 10.15, p<0.05, E/A rati o; 0.91 +/- 0.23 vs 0.68 +/- 0.14, p<0.05), these values increased to levels similar to those observed at pre-MI in the convalescent stage. There were no changes in left ventricular dimensions between pre-MI an d in the convalescent period. In patients with large MI, the changes i n the TMF patterns varied among patients after MI. In 3 patients with WMS less than or equal to 25, E and the E/A ratio were decreased in th e convalescent stage, compared with pre-MI values. In 2 patients with WMS>25, TMF patterns showed 'pseudonormalization' (E/A ratio>1.0) thro ughout the follow-up period, with a progressive increase in left ventr icular dimension. Thus, MI per se does not always produce clear change s in the Doppler TMF pattern in clinical settings, and the size of the MI seems to be a determinant of the TMF pattern after MI.