Diastolic stress test in assessing functional state of postinfarction myocardium

Abstract

Taking into account the conflicting literature data and the ambiguity in the interpretation of parameters of diastolic heart function in patients with coronary heart disease, we conducted an analysis of diastolic heart function in patients after myocardial infarction at the outpatient rehabilitation stage. Aim of the study was to investigate the diagnostic information content and the feasibility of diastolic stress testing to assess the functional condition of postinfarction myocardium. Material and methods. 86 patients were examined at the outpatient stage of rehabilitation 6 weeks after myocardial infarction with coronary artery stenting ad hoc. The control group consisted of 10 healthy volunteers. Structural and functional examination of the heart was performed at rest and immediately after exercise using stress echocardiography. Results and discussion. Patients after myocardial infarction have a larger indexed volume of the left atrium (30.71 ± 8.88 vs. 20.49 ± 4.04 ml/m2) and an E/e` ratio (8.45 ± 3.27 vs. 6.46 ± 1.42) in comparison with the control group. 38 (62.3 %) patients with normal left ventricular (LV) ejection fraction (EF) had unimpaired LV diastolic function, 19 (31.1 %) and 2 (3.3 %) patients had type 1 and type 2 diastolic dysfunction, respectively, 2 patients (3,3 %) had an indeterminate result. Patients with reduced LV EF have a significantly lower early diastolic mitral annular velocity (e`). The diastolic stress test revealed a significant post-exercise increase in E/e` in only one patient (from 8.92 to 18.37), who also had an initially reduced EF (32 %). The stress test showed no significant changes in diastolic heart parameters after exercise in patients suffering from heart failure with preserved EF, which may indicate relatively good diastolic reserves of the heart. Conclusions. Myocardial infarction is accompanied by the presence of LV diastolic dysfunction in 53,5 % of the patients at the 6th week of the rehabilitation period. The diastolic stress test is accompanied by a rare occurrence of stress-induced diastolic dysfunction (4 %) in patients with reduced LV EF after myocardial infarction.