Early Left Ventricular Function Abnormalities in Obstructive Sleep Apnea

Abstract

Introduction: Our aim was to assess by Tissue Doppler Imaging (TDI) the early left ventricular (LV) myocardial function abnormalities in obstructive sleep apnea (OSA). Methods: Thirty four patients (11 females, 23 males, aged 25-51) with newly diagnosed, nontreated OSA and normal echocardiographic parameters of LV diastolic and systolic function were investigated. The patients with known cardiovascular or respiratory disease were excluded. The LV end-systolic longitudinal strain (LS), peaksystolic longitudinal strain rate (LSR) and isovolumetric acceleration (IVA) of the septal and lateral mitral annulus was evaluated by TDI. Twenty two healthy persons (9 women, 13 men, and aged 23-48) were assessed as controls. Results: All OSA patients demonstrated significant decrease of the LV end-systolic LS: -15.7 ± 0.42% vs controls: -18.9 ± 0.56% (p<0.01) and LV peak-systolic LSR: 1.72 ± 0.63 s-1 vs 3.19 ± 0.68 s-1, respectively (p<0.001). The IVA was also reduced: the septal mitral annulus: -2.82 ± 0.45 cm/sec in OSA vs -4.03 ± 0.6 cm/sec in healthy subjects (p<0.01) and the lateral mitral annulus: -3.37 ± 0.54 cm/sec in gr. I vs -4.29 ± 0.42 cm/sec in gr. II (p<0.01). Conclusions: Tissue Doppler Imaging might be a reliable method for detection of early abnormalities in LV function in patients with OSA. Reduction of longitudinal strain, strain rate and isovolumetric acceleration might be present in patients with OSA, even without overt diastolic or systolic LV dysfunction. Further studies with larger sample size are needed.