Ventricular dilation after anterior ST-elevation myocardial infarction in the thrombolytic era

Background The aim of this work was to study changes in end-diastolic volum e 6 months after Q-wave and non-Q-wave anterior ST-elevation myocardial inf arction by echocardiography. Ventricular dilation after anterior Q-wave myo cardial infarction is well-recognized, However, there is a dearth of inform ation about the natural history of ventricular volumes after non-Q-wave myo cardial infarction. Methods one hundred ninety patients receiving thrombolytic therapy after an terior ST-elevation myocardial infarction were studied, All patients had 2D echocardiograms and 12-lead electrocardiograms recorded within 24 hours of symptoms and at 3, 42, and 180 days later. In addition, a further electroc ardiogram was recorded on day 7 to assess patients for the presence of Q wa ves. Peak creatine kinase over the first 3 days of admission was recorded. End-diastolic volume index was the study end point. Results Peak creatine kinase was strongly associated with ventricular dilat ion in both groups (P < .001). Mean end-diastolic volume in the Q-wave grou p increased significantly from day 1 to 6 months (P < .05) but did not alte r after non-Q-wave infarction. However, when patients were selected on pred efined criteria for significant change in ventricular dilation (>10 mL/m(2) ), then 35% of those with and 15% of those without Q waves fell into this c ategory. Within this group, the increase in end-diastolic volume followed a similar pattern, with the maximum percentage increase occurring between da y 1 and 6 weeks. Conclusions In the postthrombolytic group of anterior ST-elevation myocardi al infarction, a minority of patients without Q-wave development also under go significant ventricular dilation.