Left Ventricular Systolic and Diastolic Function in Obstructive Sleep Apnea: Impact of Continuous Positive Airway Pressure Therapy.

BACKGROUND: -Previous studies in obstructive sleep apnoea (OSA) were limited by study cohorts with co-morbidities which confound assessment of left ventricular (LV) systolic and diastolic function. We comprehensively evaluated LV function using two dimensional echocardiography (2DE), tissue Doppler imaging (TDI) and three dimensional echocardiography (3DE) in subjects moderate-severe OSA, who were compared to 'disease' (patients with hypertension, no OSA) and 'healthy' controls. METHODS AND RESULTS: -A total of 120 subjects (n=40 each of matched OSA, hypertension and healthy cohorts) underwent echocardiographic examination for the assessment of septal and posterior wall thickness, LV mass index, LV volumes and ejection fraction, mitral valve inflow indices (E, A), mitral annular velocity (S, E') and left atrial volume index (LAVI). OSA subjects were treated with CPAP (mean duration of 26 weeks) following which the echocardiographic parameters were reassessed. Posterior wall thickness and LV mass index were significantly higher in OSA and hypertensive groups compared to healthy. Systolic 'S' velocity was reduced in OSA and hypertensive compared to healthy (P