Obstructive Sleep Apnea Syndrome Is Associated With Impaired Pulmonary Artery Distensibility and Right Ventricular Systolic Dysfunction

Abstract

Background/aim: We investigated whether obstructive sleep apnea syndrome (OSAS) has any impact on pulmonary artery distensibility (PAD) and right ventricular (RV) function. Materials and methods: Subjects were categorized according to apnea-hypopnea index (AHI) as follows: controls (n = 17 and AHI < 5), mild-to-moderate OSAS (n = 22 and AHI = 5-30), and severe OSAS (n = 29 and AHI > 30). All subjects underwent transthoracic echocardiography after polysomnography to assess PAD and RV function. PAD was recorded as M-Mode trace of the right pulmonary artery and was defined as (PAmax-PAmin/PAmin) x 100. S' was measured by means of TDI of the lateral annulus of the RV using apical four-chamber view. Results: Patients with severe OSAS demonstrated impaired RV longitudinal systolic function (S') compared to the other groups (P < 0.05). Impaired pulmonary vasculature elastic properties as reflected by decreased PAD were more prevalent in severe OSAS (26.2 +/- 5.7%) compared to the controls (29.9 +/- 4.6%; P < 0.05) and mild-to-moderate OSAS (29.0 +/- 4.1%; P < 0.05). An inverse relation between PAD (P < 0.05), RV myocardial performance index (MPI) (P < 0.05), and AHI was demonstrated. S' also correlated with PAD (P < 0.05). Conclusion: PAD is a significant tool to evaluate pulmonary vasculature stiffening and is well correlated with disease severity in OSAS. Further, impaired PAD may lead to RV systolic dysfunction.