[Changes in left ventricular volumes after acute transmural myocardial infarction: clinical, angiographic and...

The relation of left ventricular (LV) volume changes to clinical and angiographic features was assessed in 57 patients with a first transmural myocardial infarction. LV volumes were measured by two-dimensional echocardiography within 72 hours of admission and repeated at one month. The infarct-related artery (IRA) patency and collateral circulation were determined by coronary arteriography performed before discharge. LV end-diastolic and end-systolic volumes increased (155 +/- 44 vs 203 +/- 65 ml; 96 +/- 32 vs 134 +/- 57 ml, all P less than 0.01), and ejection fraction decreased (0.38 +/- 0.06 vs 0.34 +/- 0.09, P less than 0.05) in patients with totally occluded IRA without collaterals. In contrast, LV volumes and systolic function were unchanged in those who had subtotally occluded IRA or with collaterals. LV dilation (greater than or equal to 20% increase in LV end-diastolic volume) occurred more frequently in patients without residual flow to the infarct region (77%) than in those with (9%) (P less than 0.01). Thirteen patients with LV dilation developed congestive heart failure, 3 of whom having cardiac death. However, congestive heart failure was found in only 11 patients without LV dilation and no death occurred. Thus, the cardiac event rate was higher in patients with (65%) than in those without (30%) LV dilation (P less than 0.05). The study indicates that the changes in LV volumes following acute myocardial infarction are largely related to the status of residual flow to the infarct region and affect the clinical outcome of the patients.