National Scientific Center “M.D. Strazhesko Institute of Cardiology NAMS of Ukraine”, Kyiv, Ukraine
The aim – to explore the relationship of structural and functional state of the left ventricle (LV), its geometry and intraventricular dyssynchrony with exercise tolerance (ET) in patients after Q-wave acute myocardial infarction (Q-AMI). Material and methods. The study involved 58 patients (96 % male) with post-infarction cardiosclerosis (after Q-wave myocardial infarction), average age (56.0±1.2) years. Group I included 40 patients who were examined at 10–12 days and at 6 months after Q-AMI. Group II included 48 patients after Q-AMI, who performed exercise stress test (EST). Group III included 31 patients with post-infarction cardiosclerosis from group I to assess possibility of making submaximal EST 6 months after Q-AMI. All patients underwent echocardiography and speckle tracking echocardiography (STE). Results. In 6 months after Q-AMI the value of global longitudinal systolic strain (GLS) was increased in 23 patients of group I by 9 %, LV ejection fraction (LVEF) was increased by 4 % and wall motion score index (WMSI) was decreased by 5.6 % in comparison with those parameters at 10–12 days after Q-AMI. In group II direct correlation between the
level of oxygen consumption (VO2 max) during EST and LVEF, GLS, global circumferential systolic strain at rest, as well as an inverse correlation between VO2 max and WMSI (r=–0.56; Р<0.001) and index post-systolic shortening (IPSS) (r=–0.34; Р=0.043) were established. The odds ratio (OR) to perform submaximal test in patients of group III increased along with GLS (OR 1.89; confidence interval (CI) 1.17–3.05; Р=0.010), LVEF (OR 1.22; CI 1.02–1.46; Р=0.034) and lower WMSI (OR 0.04; CI 0.004–0.44; Р=0.008) at 10–12 days after Q-AMI. It was found that in group III the value of GLS ≤ –10 % at the 10–12 days of Q-AMI allows to predict ability to perform submaximal test 6 months after Q-AMI with sensitivity of 88 % and specificity of 67 %. Conclusions. In patients after Q-AMI increasing GLS is associated with improving global and segmental LV systolic
function. Aerobic activity in patients with post-infarction cardiosclerosis is associated with LVEF, longitudinal and circumferential components of the myocardial strain, as well as amount of myocardial injury and intraventricular dyssynchrony. Early assessment of GLS in Q-AMI patients is important for predicting exercise tolerance.