Abstract
Introduction
Obstructive sleep apnea is associated with right ventricular dysfunction including preload and afterload abnormalities. Right ventricular contractility remains difficult to assess due to the complex RV geometry. Echocardiographic speckle tracking strain provides a better understanding of regional contractility. We tested the hypothesis that RV dyssynchrony exists in OSA patients and can be reversed by CPAP therapy.
Methods
Prospective study including patients with a confirmed OSA diagnosis. Echocardiographic (TTE) measurements were obtained at baseline and after one month of CPAP therapy. We measured usual TTE parameters: left ventricular ejection fraction (LVEF), transmitral pulsed Doppler including E and A waves velocities, mitral Doppler tissue imaging. The speckle tracking analysis was used to generate 6 segmental RV strain curves. Time to peak strain was determined with dyssynchrony defined as the difference between earliest and latest segments. Global radial strain was calculated.
Results
36 patients (M: 69%,mean (SD) age 56(11) yrs, body mass index 35.11(7.38) kg/m-2, respiratory disturbance index 46(18)/h) were included. At baseline, 56% had high blood pressure, 22% had a chronic heart disease, with a normal LVEF: 61(8) %. Speckle tracking strain analysis showed RV dysfunction with a decreased RV global strain: 13.8(5.8) % and RV dyssynchrony: 174 (89) ms. After one month of CPAP, RV function was significantly improved and dyssynchrony was reversed: 125 (82) ms, p=0.03.
Conclusion
We observed RV dyssynchrony at baseline in OSA patients. RV dyssynchrony was improved after one month of CPAP therapy.
- © 2012 ERS
