Evaluation Of Right Ventricular Function In Patients With Obstructive Sleep Apnoea Hypopnea Syndrome By Echocardiography

Objective: The aims of this study are to evaluate right ventricular (RV) function in newlydiagnosed obstructive sleep apnoea hypopnea syndrome (OSAHS) patients without pulmonaryarterial hypertention, and to find ultrasonic indicators that can sensitively detect changes of RVfunction in the OSAHS patients mainly using2-dimensional echocardiography, Tissue dopplerimaging (TDI),2-dimensional speckle tracking imaging (STI).Methods: In our study we selected100person who were monitored with polysomnography(PSG) during the whole night and confirmed without pulmonary arterial hypertention byechocardiography. Among them sixty patients whose Apnea Hypnea Index (AHI)≥5/h weredivided into OSAHS and sudbivided into three subgroups as: mild group, moderate group andsevere group. Forty normal subjects whose gender, age, body mass index (BMI) matched theexperimental group were selected as control group. Structure and function parameters of rightventricular by echocardiography were evaluated in all subjects.Results:1. Compared with the control group, the isovolumic contraction acceleration（IVA)of right ventricular free wall in OSAHS group is significantly decreased (P<0.05). The IVA ofmoderate and severe group is significantly lower than the mild group (P<0.05).2. The peak earlydiastolic velocity (Ea), the ratio of Ea and the peak late diastolic velocity (Aa), that is Ea/Aa, theisovolumic contraction peak velocity (IVV) of right ventricular free wall tricuspid ring in moderateand severe OSAHS groups are significantly lower than the control group (P <0.01).3. The systolicpeak strain (S), strain rate (SR) and velocity (V) of right ventricular free wall basal, middle andapex segment in moderate and severe OSAHS groups are obviously lower than the control group(P<0.05). The S and V of the basal, the V of the middle and the SR and V of the apex segment inmoderate group are lower than the mild group (P<0.05). The S, SR and V of the severe group areobviously lower than the mild group (P<0.05). The S of the middle segment in the severe group isobviously lower than the moderate group (P<0.05).4. The average displacement between the apexsegment and the tricuspid ring right ventricular free wall (TAPSEfw), the average displacementbetween the apex segment and the tricuspid ring interventricular septum (TAPSEsep), the averagedisplacement between the apex segment and the halfway point of the above two points (TAPSEmid) in moderate and severe OSAHS groups are significantly lower than the control group(P <0.05). The TAPSEfw, TAPSEsep and TAPSEmid in moderate and severe OSAHS groups arelower than the mild group (P <0.05).Conclusions: The moderate and severe OSAHS patients without pulmonary arterialhypertention will lead to the decrease of right ventricular function. Tissue doppler imaging (TDI),2-dimensional speckle tracking imaging (STI) are objective, accurate and sensitive indicators fordetecting changes of the right ventricular function in the above patients.