Diastolic function in acute myocardial infarction: a radionuclide study.

ABSTRACT

We studied left ventricular diastolic function by equilibrium gated radionuclide angiography in patients as follows 75 with acute myocardial infarction (AMI), 35 with anterior or anteroseptal necrosis (Group A) and 40 with inferior, inferolateral, or posterior necrosis (Group I). The ejection fraction (EF) was lower in Group A than Group I (41.9 +/- 2.5 vs. 57.1 +/- 2.0%, p less than 0.001), as was peak diastolic filling rate normalized to end diastolic volume (PDFR-EDV/sec) (1.9 +/- 0.1 vs. 2.4 +/- 0.1 EDV/sec, p less than 0.05). PDFR normalized to stroke volume was similar in both groups. An excellent linear correlation was found between EF and PDFR-EDV/sec in the total study population. Isovolumic relaxation period (IRP) was beyond our upper normal value of 94 msec in 64% of patients and it was shorter in Group A than I (95.8 +/- 12.7 vs. 147.0 +/- 13.6 msec, p less than 0.05). The presence of shorter IRP in Group A than in I is probably a result of an earlier mitral valve opening as a consequence of higher left atrial pressure.