Evaluation of Right Ventricular Systolic and Diastolic Function in Patients with Newly Diagnosed Obstructive Sleep Apnea Syndrome without Hypertension

Abstract

Objectives: We investigated right ventricular (RV) structural and functional cardiac alterations in obstructive sleep apnea (OSA) independent of systemic hypertension and their correlation to the severity of OSA. Methods: Forty-one moderate-to-severe OSA but otherwise healthy patients and 30 body mass index-matched control subjects were included. All subjects underwent 24-hour ambulatory blood pressure monitoring, standard and tissue Doppler imaging of the RV. Results: The OSA group had increased RV wall thickness, impaired right ventricular outflow tract fractional shortening (RVOT fs), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI) and RV myocardial acceleration during isovolumic contraction (IVA) (p < 0.001). Apnea hypopnea index (AHI) and mean pulmonary artery (PA) pressure were correlated with all these indices (p < 0.01 for all). RV free wall thickness (p < 0.001) and IVA (p = 0.006) remained significant predictors of AHI after adjusting for age, body mass index, mean PA pressure, RVOT fs, TAPSE and MPI in a multiple stepwise linear regression model. Conclusions: OSA is associated with impaired RV function despite normal systemic blood pressures. The level of RV dysfunction has a direct relationship with the severity of OSA. RV free wall thickness and IVA are independent predictors of AHI in uncomplicated OSA patients.

Simplifying STOP-BANG: use of a simple questionnaire to screen for OSA in an Asian population

“…Untreated sleep apnea in patients with severe apnea causes a 46% excess mortality over 8 years, an increase attributed chiefly to increases in cardiovascular mortality [2]. OSA has been associated with impaired RV function despite normal systemic pressures [3]. The prevalence of OSA was estimated from large population studies such as the Sleep Heart Health study at up to 18% [4], although overt prevalence is reported at 4% of men and 2% of women [1].…”

Obesity and Right Ventricular Structure and Function

“…SDB was not assessed with polysomnography, and the sensitivity and specifi city of the questions used are not clear, so residual confounding could be present. [37][38][39][40] MESA excluded individuals with weight . 300 pounds, so that morbidly obese individuals in the study may have been less than those in the general population.…”

Cardiovascular consequences of sleep apnea: II-Cardiovascular mechanisms

“…As hypoxia and pulmonary HT are associated with OSA, right heart failure is likely to establish. Accordingly, attenuated RV contractility as well as impaired RV ejection fraction and hypertrophy have all been demonstrated in OSA patients in the absence of concomitant chronic obstructive pulmonary disease and HT (55).…”