Influence of myocardial infarction size on radionuclide and Doppler echocardiographic measurements of diastolic function

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To assess the relation between myocardial infarction size and diastolic function as measured by radionuclide ventriculography and Doppler echocardiography, 83 patients (aged 58 ± 9 years) without significant valvular disease were studied 8 to 12 weeks after an acute myocardial infarction. Myocardial infarction size was measured by resting thallium-201 tomography. Peak early filling rate (in end-diastolic volumes/s) was measured by gated blood pool scintigraphy. Doppler measures of mitral inflow were peak early (E) and atrial (A) filling velocities, slopes of E and A, percent E and A filling, E A ratio and diastolic filling period. In univariate analyses, there was a significant inverse correlation between infarction size and the peak early filling rate (r = −0.59, p < 0.001), and this remained significant (r = −0.63, p < 0.0001) in an analysis that included 2 other determinants of the filling rate, age and diastolic filling period. Infarction size was directly correlated to the peak E velocity (r = 0.37, p < 0.01), deceleration of E (r = 0.41, p < 0.01) and percent E filling (r = 0.31, p < 0.01), and was inversely correlated to peak A (r = −0.27, p < 0.05) and percent A filling (r = −0.26, p < 0.05). The correlation of myocardial infarction size with the E A ratio was r = 0.43 (p < 0.01) and remained significant in a multivariate analysis that included age and diastolic filling period (r = 0.53, p < 0.001). Thus, a larger myocardial infarction size was associated with a reduced peak early filling rate by radionuclide angiography, a higher peak E and a lower peak A velocity, and an increased E A ratio by Doppler. In addition to the other variables known to influence diastolic measurements, these results suggest that myocardial infarction size determines, in part, diastolic function as assessed by either radionuclide or Doppler techniques.