Effects of nonsurgical coronary reperfusion on the left ventricle in human subjects compared with conventional treatment. Study of 18 patients with acute myocardial infarction treated with intracoronary infusion of streptokinase.

Left ventricular function was assessed sequentially with biplane cineventriculography in 18 patients with acute myocardial infarction, in whom nonsurgical reperfusion was achieved within 8.2 +/- 6.9 hours (mean +/- standard deviation) after the onset of chest pain with intracoronary infusion of streptokinase (2,000 units/min for 66 +/- 16 minutes). Ejection fraction increased from 51.4 +/- 9.8 percent before reperfusion to 55.9 +/- 9.0 percent immediately after completion of streptokinase infusion (n = 13, p less than 0.01); the length of the akinetic myocardial segment decreased from 10.2 +/- 6.1 to 7.1 +/- 4.9 cm (p less than 0.025). Left ventricular function data before reperfusion and in the chronic stage of infarction (before surgery) were compared with data obtained in two medically treated groups that were matched retrospectively: control group I, nine patients with permanent obstruction of the infarcted vessel; control group II, nine patients with spontaneous recanalization of the initially obstructed vessel. In the acute stage of infarction, ejection fraction and akinetic segment length were comparable in the three groups. In the chronic stage ejection fraction was higher in the study group (57.4 +/- 12.7 percent) than in control group I (43.4 +/- 7.6 percent, probability [p] less than 0.05); the akinetic segment was shorter in the study group (4.5 +/- 6 versus 9.4 +/- 5.5 cm, p less than 0.025). Preservation of R waves was more extensive in the study group. Intraoperative inspection in 10 study group patients and transmural biopsy performed in 3 of these patients revealed the bulk of reperfused myocardium to be viable. It is concluded that jeopardized myocardium was preserved by nonsurgical reperfusion during the acute stage of coronary occlusion.