Biventricular Myocardial Performance Is Impaired in Proportion to Severity of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular morbidity and death. Little information is available regarding the relationship between the severity of OSA and myocardial performance in OSA patients who have normal ejection fractions. We prospectively investigated this relationship, using the tissue-Doppler myocardial performance index (TD-MPI). We conducted overnight, full-laboratory polysomnographic examinations of 116 patients, and calculated the left and right ventricular TD-MPIs. Patients were classified into 3 groups in accordance with their apnea-hypopnea index (AHI) levels: AHImild (≥5 to <15), AHImoderate (≥15 to <30), and AHIsevere (≥30). Left and right ventricular TD-MPI values were higher in the AHIsevere group than in the AHImild and AHImoderate groups (all P <0.05). In addition, right ventricular TD-MPI values in the AHImoderate group were higher than those in the AHImild group (P <0.05). Right ventricular TD-MPI was significantly associated with AHI (β=0.468, ...