Hemodynamic evaluation by M-mode echocardiography in acute myocardial infarction

We assessed the relationship between echocardiographic and hemodynamic parameters in 28 patients with documented acute myocardial infarction (AMI), who underwent M-mode echocardiography and Swan-Ganz catheterization during the same hospitalization. Patients with valvular heart disease were excluded from the study. On mitral valve echogram, DE interval was measured and the area enclosed by mitral valve echogram during DE interval (DE subarea ) was calculated in each echocardiogram. DE subarea /DE interval ratio was computed for each measurement set. Hemodynamic parameters were obtained in the usual fashion. Patients with pulmonary artery wedge pressure (PWP) less than 18 mm Hg showed a DE interval markedly longer than patients with PWP greater than 18 mm Hg: 81.72 +/- 15.23 vs 55.12 +/- 9.85 msec (p less than 0.001). Patients with cardiac index greater than 2.2 L min-1 m-2 had a DE subarea /DE interval ratio greater than patients with cardiac index less than 2.2 L min-1 m-2: 0.169 +/- 0.035 vs 0.094 +/- 0.017 dm2 sec-1 (p less than 0.001). Echocardiographic and hemodynamic data were then correlated in the whole study group, and it was found that DE interval was significantly (p less than 0.001) and inversely correlated to PWP; stroke index more than cardiac index was correlated (p less than 0.005) both to DE subarea /DE interval ratio and to DE interval itself; DE interval was not affected by heart rate. We were able to categorize the patients into four subsets on the basis of echocardiographic measurements. Our findings suggest the possibility of providing, through M-mode echocardiography, a noninvasive and accurate evaluation of PWP and stroke index.