Evaluation Of Left Atrial Function In Patients With Hypothyroidism By Two-dimensional Speckle Tracking Echocardiography And Three-dimensional Echocardiography

Objective: To investigate the changes of left atrial(LA)function in patients with hypothyroidism by two-dimensional speckle-tracking echocardiography(2D-STE)and real-time three-dimensional echocardiography(RT-3DE).Methods: from November 2016 to February 2018,42 patients who were newly diagnosed and met the diagnostic criteria of hypothyroidism in the endocrinology clinic of affiliated zhongshan hospital of Dalian University were selected as hypothyroidism group(13 male,29 female;age 20~59 years;mean age 41.38 ± 9.52 years),and 38 patients with complete 3 month treatment data were included in the post-treatment group(11 male,27 female;age 20~59 years;mean age 41.18 ± 9.75 years).45 healthy subjects were selected as control group(13 male,32 female;age 24~62 years;mean age 42.44 ± 8.58 years).Main measurement indicators: 1.using two-dimensional echocardiography to measure end-systolic left ventricular diameter(LVESD),end-diastolic left ventricular diameter(LVEDD),end-diastolic interventricular septal thickness diastolic(IVSd),end-diastolic left ventricular posterior wall thickness(LVPWd),end-systolic left atrial diameter(LAD).Left ventricular ejection fraction(LVEF)was calculated by biplane Simpson ‘s method.2.clear two-dimensional gray-scale dynamic images of left atrium were acquired,the longitudinal strain rate curves of each segment of left atrial septum,lateral wall,inferior wall,anterior wall were obtained by using Qlab image analysis software offline,the waveform peaks on the curves were recorded,including systolic longitudinal peak strain rate(SRs),early-diastolic longitudinal peak strain rate(SRe)and late-diastolic longitudinal peak strain rate(SRa).The atrial wall was divided into three sections: roof segment,middle segment and basal segment.3.the left atrial full volume images were stored and make off-line analysis,to obtain the left atrial volume parameters: maximum left atrial volume(LAVmax),minimum left atrial volume(LAVmin),pre-contraction left atrial volume(LAVp),corrected by body surface area for maximum left atrial volume index(LAVImax),minimum left atrial volume index(LAVImin),pre-contraction left atrial volume index(LAVIp),and calculate left atrial total ejection fraction(LATEF),left atrial passive ejection fraction(LAPEF)and left atrial active ejection fraction(LAAEF).Results: 1.the parameters of conventional echocardiography were compared: there were no significant difference in the parameters of LVESD,LVEDD,IVSd,LVPWd,LAD and LVEF between groups(P>0.05).2.2D-STE parameters: before treatment,SRs and SRe of each segment in hypothyroidism group were lower than those in control group,SRa was higher than control group,the differences were statistically significant(P<0.05).After treatment,SRs and SRe of each segment in hypothyroidism group were significantly higher than before(P<0.05),and SRa of each segment in hypothyroidism group was not significantly different from those before(P>0.05).After treatment,SRs of middle segment and SRe of each segment in hypothyroidism group were significantly lower than those in control group(P<0.05),and SRa of each segment was significantly higher than those in control group(P<0.05).There was no significant difference between hypothyroidism group after treatment and control group in SRs of basal and roof segments(P>0.05).3.RT-3DE parameters: there were no significant difference in the parameters of LAVImax,LAVImin,LAVIp and LATEF between groups(P>0.05).LAPEF in both before and after treatment hypothyroidism group were reduced in comparison with control group,while both LAAEF were increased in comparison with control group(P<0.05).4.the correlation analysis of some strain rate parameters(the differences were more obvious between the before treatment hypothyroidism group and control group,such as left atrium middle segment SRe,basal segment SRe and roof segment SRa),LAPEF,LAAEF and thyroid stimulating hormone(TSH)showed that there was a negative correlation between absolute value of left atrium middle segment SRe,LAPEF and TSH(r=-0.380,P=0.001;r=-0.485,P<0.001),and there was a positive correlation between LAAEF and TSH(r=0.301,P=0.007).There were no significant correlation between the absolute value of left atrial basal segment SRe and roof segment SRa and TSH(r=-0.183,P=0.105;r=0.048,P=0.671).Conclusions: 1.Hypothyroidism could lead to the decrease of left atrium function,and the left atrium reservoir,conduit,and booster pump had been impaired when the heart configuration had not changed significantly.2.2D-STE and RT-3DE could be used to evaluate left atrial function in patients with hypothyroidism.The left atrium mid segment strain rate(SR)in 2D-STE,LAPEF and LAAEF in RT-3DE were expected to be valuable markers for early assessment of left atrial function impairment in patients with hypothyroidism.3.Early and effective treatment of hypothyroidism was important to improve left atrial function,and the recovery of reservoir function and conduit function may be earlier than booster pump function.