Right ventricular diastolic dysfunction in patients with obstructive sleep apnea syndrome

BACKGROUND AND OBJECTIVES: This study aimed to assess right ventricular (RV) diastolic dysfunction in patients with obstructive sleep apnea syndrome (OSAS) using velocity vector imaging (VVI) and to evaluate the application of VVI technology. METHODS: According to the apnea-hypopnea index (AHI), 69 patients with OSAS were divided into three groups: mild, moderate, and severe. A total of 35 cases of healthy subjects were enrolled as the control group. Digital images of apex four-chamber views were acquired to measure the peak early diastolic strain rate (RV-SRe), late diastolic strain rate(RV-SRa), and RV-SRe/RV-SRa using VVI. RESULTS: RV-SRe, RV-Sra, and RV-SRe/RV-SRa were decreasing along with the disease severity. RV-SRe, RV-SRe/RV-SRa in moderate and severe OSAS group showed lower than control and mild OSAS groups. RV-SRa in severe OSAS group showed lower than control group. RV-SRe had the best correlation with AHI than other parameters. CONCLUSIONS: Right ventricular diastolic dysfunction starts before the development of heart failure and pulmonary hypertension in patients with OSAS. RV-SRe was the parameter that may reflect subclinical myocardial dysfunction and can better reflect RV diastolic dysfunction.