[Effect of thrombolysis on rupture of the left ventricular free wall following acute myocardial infarction].

Rupture of the left ventricular free wall is one of the most serious sequels of acute myocardial infarction (AMI) and results in hospital death. The effectiveness of thrombolytic therapy for AMI to prevent rupture of the left ventricular free wall was studied retrospectively in 31 patients (2.6%) among 1,210 consecutive patients admitted to our hospital within 48 hours after the onset of AMI. All patients were divided into three groups: 758 without reperfusion therapy (conventional group), 113 who underwent direct percutaneous transluminal coronary angioplasty (direct PTCA group), and 339 who received thrombolytic therapy with or without PTCA (thrombolysis group). No rupture was found in the direct PTCA group. No significant difference could be found in the incidence of the rupture between the conventional group (19 patients, 2.5%) and the thrombolysis group (12 patients, 3.5%). When early rupture and late rupture are defined as occurring less and more than 48 hours from the onset of AMI, 14 early ruptures (1.8%) and 5 late ruptures (0.7%) were found in the conventional group, and 9 early ones (2.7%) and 3 late ones (0.9%) in the thrombolysis group. There was no significant statistical difference between the two groups. The incidence of the rupture according to the result of the reperfusion therapy was much higher in the unsuccessful group (five patients, 7.8%; p < 0.02) than in the successful group (seven patients, 2.5%; p < 0.002). All ruptures in the successful group appeared early; but only two early rupture cases (3.1%) out of five were found in the unsuccessful group. The mean interval between the thrombolysis and the rupture was 3.9 +/- 1.2 hours in the successful group, which was much shorter than that of the unsuccessful group (67.1 +/- 28.5 hours; p < 0.05). We conclude that thrombolytic therapy, if successful, may be effective to decrease late rupture of the left ventricular free wall, but may be ineffective to prevent early rupture.