0119: Impact of obstructive sleep apnea on global left ventricular myocardial performance

Objective To determine the impact of obstructive sleep apnea (OSA) on left ventricle (LV) structure and function and to search for a relationship between systolic LV function and severity of OSA. Methods 40 subjects without any cardiac or pulmonary disease, referred for evaluation of OSA had overnight polysomnography and complete echocardiographic assessment with estimation of left ventricular myocardial performance index (MPI) by tissue Doppler method. According to apnea hypopnea index (AHI), subjects were divided into two groups: patients with moderate OSA (AHI=15-30/h, n=18), and patients with severe OSA (AHI ≥30/h, n=22). Results were compared using ANOVA. The correlation between OSA severity and these variables was determined with Pearson's correlation coefficient. Results There was no significant difference between the 2 groups in clinical data. Ventricular septal and posterior wall thicknesses, LV mass index and LV end-diastolic and end-systolic volume index were similar between the groups. Patients with severe OSA had shorter aortic ejection times (288±32 ms vs 267±23 ms; p=0.02, for severe and no severe OSA respectively) and a higher MPI (0.61±0.14 vs 0.50±0.17; p=0.036, respectively). A correlation was found between OSA severity and left MPI (r=0.36, p=0.019), and aortic ejection times (r=–0.28; p=0.046). Conclusions MPI of left ventricle and aortic ejection time are altered in severe OSA and are correlated to AHI severity.