[Noninvasive estimation of the left ventricular filling pressure by E/Em during exercise in the early stage of acute myocardial infarction].

OBJECTIVE: To validate a Doppler index of diastolic filling (E/Em) during exercise in the early stage of the patients with acute myocardial infarction,and investigate its association with exercise capacity.

METHODS: The study enrolled consecutive 60 patients with first ST segment elevation myocardial infarction(STEMI)in Killip I-II stage and who underwent percutaneous coronary intervention (PCI) from March 2008 to August 2008(as study group), At 10-14 days after acute myocardial infarction, Cardiopulmonary Exercising Testing (CPET, Modified Bruce flat treadmill protocol, symptom-limited flat exercise tolerance test) was conducted with Tissue Doppler Imaging (TDI) evaluation at rest and instantly during exercising peak. Doppler index of diastolic filling was also measured at rest and immediately after Cardiopulmonary Exercising Testing in 30 age-matched patients as control whose coronary angiography (CAG) or coronary computed tomography was negative.

RESULTS: All patients completed the TDI evaluation at rest and after CPET. There was no significant difference in E/Em measured by TDI in control group at rest and during exercise. In study group, 29(48%,29/60) patients had a normal E/Em both at rest and exercise, 21(35%,21/60) patients had elevation of E/Em at rest, and 10(17%,10/60) patients had elevation of E/Em only during exercise. There was a good negative correlation between E/Em and metabolic equivalent at rest (r=-0.54, P<0.01) and during exercise (r=-0.40, P<0.01). The patients which E/Em>10 at rest(METs is 4.6+/-1.6, P<0.01) and patients who had E/Em>10 only during exercise (METs is 5.8+/-1.6, P<0.01) had a reduced exercise capacity compared with the patients with normal E/Em both at rest and during exercise (METs is 6.2+/-1.8).

CONCLUSION: The ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/Em) by the stress echocardiography can be used to reliably identify the patients with acute myocardial infarction with elevated LVFP during exercise and reduced exercise capacity.