实时三维超声心动图评估亚临床甲状腺功能减低患者治疗前后左房结构及功能变化

Assessment of left atrial structure and function in patients with subclinical hypothyroidism before and after treatment by real-time three-dimensional echocardiography

目的应用实时三维超声心动图(RT-3DE)技术评价亚临床甲状腺功能减低(SCH)患者治疗前后左房结构及功能变化。方法选取我院临床诊断为亚临床甲状腺功能减低(SCH)且接受左甲状腺素钠治疗者31例(SCH组),另选同期健康体检者33例为对照组;SCH组于甲状腺功能达正常水平3个月后随访超声心动图,比较SCH组治疗前后及对照组二维超声参数即左房内径(LAD),左室射血分数(LVEF)、左房容积(LAV)、经体表面积标化的左房容积指数(LAVI)、二尖瓣舒张早晚期血流速度(E峰、A峰)、二尖瓣E峰减速时间(EDT)、舒张早期三尖瓣环左室侧壁侧和室间隔侧运动速度(Lat e’和Sep e’)及其平均值(e’)、E/e’,以及RT-3DE测得的左房结构参数[左房最大容积(LAVmax)、左房收缩前容积(LAVpre)、左房最小容积(LAVmin)、左房总排空分数(LAEF)、左房被动排空分数(LApEF)及左房主动排空分数(LAaEF)]及应变参数[左房储备期应变(LASr)、左房管道期应变(LAScd)、左房收缩期应变(LASct)];分析血清促甲状腺激素(TSH)水平与LAEF、LApEF、LAaEF的相关性。结果对照组及SCH组治疗前、后二维超声参数LAD、LAV、LVEF、E峰、A峰、EDT、Lat e’、Sep e’、e’、E/e’比较差异均无统计学意义。与对照组及SCH组治疗前比较,SCH组治疗后LAVpreA、LAVmin、LAaEF均降低,LAEF、LApEF均增加,差异均有统计学意义(均P<0.05);SCH组治疗后LAVmax、LAVpreA、LAVmin、LAEF、LApEF、LAaEF与对照组比较差异均无统计学意义;各组LAVmax比较差异无统计学意义。与SCH组治疗前比较,SCH组治疗后LASr、LAScd均增加,LASct降低,差异均有统计学意义(均P<0.05);与对照组比较,SCH组治疗后LASr、LAScd均减低,LASct增加,差异均有统计学意义(均P<0.05)。Pearson相关分析法显示,治疗前TSH水平与LAEF无关(r=0.16,P=0.39),与LApEF呈负相关(r=-0.44,P=0.01),与LAaEF呈正相关(r=0.45,P=0.01)。结论 RT-3DE技术可早期发现SCH患者左房容积和机械功能损伤,且经左甲状腺素钠治疗后SCH患者左房损伤情况明显改善。

ObjectiveTo evaluate the changes of left atrium structure and function in patients with subclinicalhypothyroidism(SCH)before and after treatment by real-time three-dimensional echocardiography(RT-3 DE).MethodsThirty-one SCH patients(SCH group)who were received levothyroxine tablets in our hospital were selected.Another 33 cases of healthysubjects at the same period were selected as the control group.Follow-up echocardiography was performed in SCH group afterthyroid function returned to normal for 3 months. Left atrial conventional parameters were obtained by two-dimensionalultrasound,including left atrium diameter(LAD),left ventricular ejection fraction(LVEF),left atrium volume(LAV),left atrialvolume index(LAVI)normalized by body surface area,early and late mitral diastolic blood flow velocity(peak E,peak A),mitralvalve E peak deceleration time(EDT),average value e’and E/e’. Left atrium structure parameters including left atriummaximum volume(LAVmax),left atrium pre-systolic volume(LAVpre),left atrium minimum volume(LAVmin),left atrium totalemptying index(LAEF),left atrium passive emptying index(LAp EF)and the left atrial active evacuation index(LAa EF),the strain parameters including the left atrial reserve strain(LASr),the left atrial duct strain(LAScd)and the left atrial contractionstrain(LASct)were obtained by RT-3 DE.The differences of the above parameters before and after treatment in SCH group andcontrol group were compared.Pearson correlation analysis was used to detect the correlation between TSH levels and LAEF,LAp EF,and LAa EF before treatment.ResultsThere were no statistical differences of LAD,LAV,LVEF,E peak,A peak,EDT,Late e’,Sep e’,e’,E/e’between the control group and the SCH group before and after treatment.Compared with the controlgroup and the SCH group before treatment,LAVpre A,LAVmin and LAa EF in the SCH group after treatment were decreased,while LAEF and LAp EF were increased,and the differences were statistically significant(all P<0.05). LAVmax,LAVpre A,LAVmin,LAEF,LAp EF and LAa EF in the SCH group after treatment were not statistically significant compared with the controlgroup. There was no statistically significant difference of LAVmax among the groups. Compared with the SCH group beforetreatment,LASr and LAScd in the SCH group after treatment were increased,while LASct was decreased,and the differenceswere statistically significant(all P<0.05).Compared with the control group,LASr and LAScd in the SCH group after treatmentwere decreased,while LASct was increased,the differences were statistically significant(all P<0.05). Pearson correlationanalysis showed that TSH level was not correlated with LAEF before treatment(r=0.16,P=0.39),negatively correlated withLAp EF(r=-0.44,P=0.01),and positively correlated with LAa EF(r=0.45,P=0.01).ConclusionThe left atrial volume andmechanical function damage of SCH patients can be detected early by RT-3 DE technology,and the left atrial damage of SCHpatients is significantly improved after treatment with levothyroxine tablets.