COMPARISON OF DEGREES OF LEFT-VENTRICULAR DILATION WITHIN 3 HOURS ANDUP TO 6 DAYS AFTER ONSET OF FIRST ACUTE MYOCARDIAL-INFARCTION

Following an acute myocardial infarction (AMI) there is immediate dete rioration of contractility in the infarcted left ventricular (LV) wall , This can be followed by regional dilation (expansion) as well as glo bal remodeling, We examined 35 consecutive patients-with no history of myocardial ischemia-who were admitted to hospital within 3 hours afte r initial symptoms and with ST-segment changes on an electrocardiogram consistent with transmural ischemia. Echocardiography was performed a t admission, and at 6 hours, 12 hours, 24 hours, 3 days, and 6 days af ter onset of the AMI, Within 3 hours after onset of symptoms an increa se in both end-diastolic volume index (EDVI) and end-systolic volume i ndex (ESVI) was found in both anterior and inferior infarcts when comp ared with healthy controls (mean +/- SD EDVI: 99 +/- 13 ml/m(2) [anter ior], 69 +/- 17 ml/m(2) [interior], 51 +/- 15 ml/m(2) [controls], p le ss than or equal to 0.00001; ESVI: 62 +/- 12 ml/m(2) [anterior], 38 +/ - 11 ml/m(2) [inferior], 17 +/- 6 ml/m(2) [controls], p less than or e qual to 0.00001), At all points in time, volumes were larger in anteri or infarcts than in inferior infarcts (p < 0.05), The volumes did not change during the 6 days (p > 0.1). Thus, major LV dilation is present within 3 hours after onset of symptoms of first AMI. The dilation is more pronounced in anterior versus inferior infarcts. From 3 hours unt il day 6 no further changes in LV volumes occurred. (C) 1997 by Excerp ta Medico, Inc.