Remodeling and Changes of Systolic and Diastolic Functions of Left Ventricle after Acute Myocardial Infarction: Comparison according to Killip Class at Admission

ABSTRACT

BACKGROUND: Infarct size determines left ventricular (LV) systolic and diastolic dysfunctions after acute myocardial infarction, and also may affect the recovery from functional impairment. We studied the differences of LV remodeling and changes of systolic and diastolic functions of LV during two weeks after acute myocardial infarction, according to Killip class at admission. METHODS: Echocardiographic examinations were performed within two days (23.9+/-2.3 hours), and two weeks after the attack in 27 patients with acute myocardial infarction, and the results were compared with those of 19 controls. Patients were divided into two groups according to Killip class at admission; 18 patients in Killip class I (group I) and 9 patients in Killip class II to IV (group II). Group II had larger infarct, reflected by higher levels of peak serum cardiac enzymes. RESULTS: LV systolic function was more depressed in group II. Regional wall motion score index decreased in group I after two weeks, but not in group II. LV systolic and diastolic volume indexes increased after two weeks in group II but not group I. E/A ratio of mitral inflow was less than 1, and isovolumic relaxation time was prolonged in group I immediately after the attack. Group II had E/A>1 and shorter deceleration time (DT) of mitral inflow, and higher peak reverse flow velocity associated with atrial contraction (AR) of pulmonary venous flow than those of controls immediately after the attack. In group II, E/A ratio was greater, DT was shorter, peak systolic/diastolic flow velocity ratio of pulmonary venous flow was less, and AR was higher than those of controls after two weeks. CONCLUSION: Infarct size affected remodeling and changes of systolic and diastolic functions of LV after acute myocardial infarction. In patients with large infarct, LV was dilated and regional wall motion was not improved during two weeks. Restrictive pattern of LV filling, which was more aggravated during two weeks, was noted immediately after the attack. In patients with small infarct, LV was not dilated and regional wall motion was improved during two weeks. LV filling pattern showed relaxation abnormality.