三维斑点追踪技术评价阻塞性睡眠呼吸暂停对左室收缩功能的影响

Evaluation of left ventricular systolic function in patients with obstructive sleep apnea syndrome by three-dimensional speckle tracking imaging

目的应用三维斑点追踪(3D-STI)技术早期评价阻塞性睡眠呼吸暂停综合征(OSAS)患者左室整体收缩功能,并探讨其左室应变与睡眠呼吸暂停程度的关系。方法选取OSAS患者41例,根据睡眠呼吸暂停低通气指数(AHI)将其分为轻度组10例、中度组11例及重度组20例;另选年龄、性别与之匹配的正常成人20例为对照组。应用常规超声测量室间隔及左室后壁厚度、左室质量指数(LVMI)、左室射血分数(LVEF)、舒张早晚期二尖瓣血流峰值速度(E、A)及舒张早期心肌速度(e’);应用3D-STI技术测量收缩期左室心肌整体长轴应变(GLS)、整体径向应变(GRS)、整体环向应变(GCS)及左室面积应变(GAS),比较各组间差异,分析左室面积应变参数与心血管危险因素的相关性。结果 (1)OSAS各组患者室间隔厚度、左室后壁厚度及E/A与对照组比较差异均有统计学意义(均P<0.05),重度组E/e’大于其余各组(均P<0.05);重度组LVMI大于对照组,差异有统计学意义(P<0.05);(2)OSAS各组患者GLS和GAS均小于对照组,且随病情程度加重呈递减趋势;重度组GRS小于中度组,GCS小于其他各组(均P<0.05);(3)GAS与AHI和体质量指数均呈正相关(r=0.616、0.367,均P<0.05),与最低血氧饱和度呈负相关(r=-0.663,P<0.05)。结论 OSAS患者在LVEF正常的情况下左室心肌收缩功能受损,且受损程度与OSAS的严重程度成正比;GAS的受损与AHI、体质量指数及最低血氧饱和度相关。

Objective To evaluate the left ventricular global systolic function in early stage in patients with obstructive sleep apnea syndrome(OSAS) by three-dimensional speckle tracking imaging(3D-STI),and to investigate the correlation between severity of sleep apnea and left ventricular strain. Methods A total of 41 patients diagnosed as OSAS were selected and divided into mild group with 10 cases,moderate group with 11 cases and severe group with 20 cases according to the sleep apnea hypopnea index(AHI). Another 20 cases of normal adults with matching age and gender were selected as control group. The ventricular septal thickness,left ventricular posterior wall thickness,left ventricular mass index(LVMI),left ventricular ejection fraction(LVEF),the peak velocity of mitral vavle in early and late diastolic(E,A),and myocardial velocity(e’) in early diastolic were measured by conventional echocardiography. The left ventricular systolic peak strain in different directions including global longitudinal peak systolic strain(GLS),global radial peak systolic strain(GRS),global circumferential peak systolic strain(GCS) and global area peak systolic strain(GAS) were measured by 3D-STI.The differences between two groups was compared,and the correlation between left ventricular area strain parameters and cardiovascular risk factors was analyzed. Results ①There were significant difference in septal thickness,left ventricular posterior wall thickness and E/A in OSAS patients compared with those in control group(all P<0.05). E/e’ in severe group was larger than that in other groups(all P<0.05),the LVMI in severe group was larger than that in control group(P<0.05). ②GLS and GAS were lower in OSAS patients than those in control group,and showed a decreasing trend as the severity of the disease progressed.GRS in severe group was lower than that in moderate group,GCS in severe group was lower than that in other groups(all P<0.05). ③GAS was positively correlated with AHI and BMI(r=0.616,0.367,all P<0.05),and negatively correlated with minimal oxygen saturation(r=-0.663,P<0.05). Conclusion The left ventricular systolic function is impaired in patients with OSAS even the LVEF is normal,and the extent of damage is proportional to the severity of OSAS. The damage of left ventricular area strain has correlation with AHI,BMI and minimal oxygen saturation.