Abstract 14853: Subclinical Impairment of Right Ventricular Function in Patients with Obstructive Sleep Apnea
Background: Repetitive hypoxia during obstructive sleep apnea (OSA) is associated to frequent episodes of transient nocturnal pulmonary hypertension. Whether patients with moderate-to-severe OSA develop diurnal pulmonary hypertension and consequently right heart dysfunction is currently under study. Aim: To assess right ventricular (RV) systolic function and diurnal pulmonary artery pressure in patients with moderate-to-severe OSA, before starting treatment, by comparison with normal subjects.
Methods: We studied 40 patients (55±12 years, 6 women): 20 patients with moderate-to-severe OSA (mean apnea-hypopnea index 43±23) and no clinical signs of RV dysfunction, and 20 control, age- and sex- matched normal subjects. We assessed RV systolic function and pulmonary artery pressure by standard echocardiography: RV and right atrium (RA) diameters, tricuspid annular systolic excursion (TAPSE), RV fractional area shortening (RVFAS), pulmonary artery acceleration time (AT), systolic pulmonary artery pressure (SPAP); and also by tissue Doppler: isovolumetric acceleration (IVA), systolic velocity of the lateral tricuspid annulus (S), and RV myocardial performance index (RVMPI); and by 2D speckle tracking echocardiography: RV global longitudinal strain (RVGLS).
Results: Standard echocardiography parameters were not different between the two groups. Although within the normal range, tricuspid annular systolic velocity, IVA, and RVGLS were significantly lower, while RVMPI was significantly higher in the OSA group; similarly, SPAP was normal in both groups, however significantly higher in the OSA group (see table).
Conclusion: Chronic recurrent hypoxia during OSA causes subclinical right ventricular systolic dysfunction, which can be diagnosed by tissue Doppler and speckle tracking, and higher diurnal SPAP values. These suggest that treatment is mandatory in this often neglected sleep disorder.
- © 2012 by American Heart Association, Inc.