Abstract
Changes in transmitral flow and the clinical course of 112 patients with myocardial infarction were monitored from the acute phase to one year after onset. The clinical importance of the peak velocity of atrial filling was verified. The patients were divided into three groups in accordance with the peak atrial filling velocity in the acute phase. As compared with values obtained from age-matched normal controls, the velocity decreased in 31 patients (28 %) (Group L), similar in 68 (61 %) (Group N), and increased in 13 (12%) (Group H). During the acute phase, 22 (70.9 %) of the 31 patients in Group L suffered severe heart failure which resulted in the death of 2 (13.3 %). In Groups N and H, only a few patients suffered heart failure and death during the acute and chronic phases. Pulmonary artery wedge pressure in Group L, as measured with a Swan-Gantz catheter, increased significantly to 17.9±7.8 mmHg, with a significant decrease of the cardiac index to 2.2±0.71 l/min/m^2, during the acute phase. During the chronic phase, LVEF significantly decreased to 40.6 ±12.5%. In addition, 13 patients in group L had associated mitral regurgitation with hypertrophy of the left atrium of up to 35 mm or more in diameter. Of these 13 patients, 9 (69.2 %) died. Prognosis appears to be poor when peak atrial filling velocity decreases during the acute phase of mitral regurgitation with hypertrophy of the left atrium as a result of decreased cardiac output and elevation of left atrium pressure.
