超声心动图评价平板运动负荷后心脏舒张功能分级与左心房应变的关系

Relationship between diastolic function grade and left atrial strain in treadmill exercise stress echocardiography

目的采用超声心动图研究平板运动负荷后心脏舒张功能分级与左心房应变的关系。方法纳入空军军医大学唐都医院自2018年5月至2019年2月92例进行平板运动负荷超声评估舒张功能的受试者,使用Philips CX50超声诊断仪测量常规超声指标,QLAB软件进行左心房容积及应变分析。对受试者运动负荷试验的一般资料、常规超声指标及左心房应变指标以舒张功能分级(正常、舒张功能Ⅰ级、Ⅱ级和Ⅲ级)为组别进行单因素方差分析,采用LSD-t检验进一步行组间的两两比较。结果平板运动试验后,86.6%(58/67)的患者在负荷试验后舒张功能得到了重新分级。左心形态指标(舒张末期内径、收缩末期内径及左心房容积指数)在舒张功能不良Ⅱ级和Ⅲ级患者中显著增大,与正常对照组和舒张功能不良Ⅰ级患者比较,差异均具有统计学意义(P均<0.001);对照组及各舒张功能不良组射血分数及二尖瓣E峰比较差异均无统计学意义(P均>0.05)。舒张功能不良Ⅰ级患者E/A低于其他各组,Ⅲ级患者E/A高于其他各组,舒张功能不良Ⅱ级和Ⅲ级患者的二尖瓣e′显著低于正常对照和舒张功能不良Ⅰ级患者,E/e′在舒张功能不良Ⅱ级和Ⅲ级患者中显著升高,且Ⅲ级患者最高;左心房应变的储备功能、通道功能、泵功能在正常对照和各舒张功能不良分组患者中逐级减低:正常对照vs舒张功能不良Ⅰ级vs舒张功能不良Ⅱ级vs舒张功能不良Ⅲ级,储备功能:(42.2±8.9)%vs(34.3±7.3)%vs(24.6±5.8)%vs(17.4±5.0)%;通道功能:(20.4±5.6)%vs(15.5±3.9)%vs(10.5±2.5)%vs(8.1±2.3)%;泵功能:(21.7±4.6)%vs(18.7±3.9)%vs(14.1±2.7)%vs(9.2±2.8)%,组间差异均具有统计学意义(P均<0.001)。结论平板运动负荷后左心房应变指标与舒张功能不良分级存在单向对应关系,即舒张功能不良越重,左心房应变储备功能、通道功能、泵功能均越低。左心房应变具有单指标运动负荷超声心动图舒张功能评估的潜力。

Objective To study the relationship between cardiac diastolic function grade and left atrial strain in treadmill exercise stress echocardiography.Methods Ninety-two subjects who underwent treadmill exercise stress echocardiography for diastolic function evaluation at Tangdu Hospital,Air Force Medical University from May 2018 to February 2019 were recruited.Conventional echocardiographic parameters were determined using the Philips CX50 system,and left atrial volume and strain were analyzed with QLAB software.All data were compared using one-way ANOVA based on diastolic function grade.Post hoc analyses were performed between each group using LSD-t test.Results After treadmill exercise stress,86.6%(58/67)of patients were reclassified into new diastolic dysfunction grades.Left ventricular enddiastolic and systolic diameters,and left atrial volume index increased in the diastolic dysfunction grades II and III groups.Eject fraction and E of mitral valve were similar among all groups.E/A was lowest in the control group and highest in the diastolic dysfunction grade III group.The e'was significantly lower in the diastolic dysfunction grades II and III groups than in the normal control and grade I groups.The E/e'was elevated in the diastolic dysfunction grades II and III groups.The reservoir,conduit,and pump function of left atrial strain decreased gradually with aggravation of diastolic dysfunction[normal control vs diastolic dysfunction grade I vs grade II vs grade III reservoir function:(42.2±8.9)%vs(34.3±7.3)%vs(24.6±5.8)%vs(17.4±5.0)%,P<0.001;conduit function:(20.4±5.6)%vs(15.5±3.9)%vs(10.5±2.5)%vs(8.1±2.3)%,P<0.001;pump function:(21.7±4.6)%vs(18.7±3.9)%vs(14.1±2.7)%vs(9.2±2.8)%,P<0.001].Conclusion The left atrial strain parameters are unidirectionally related with diastolic function grades,i.e.,the reservoir,conduit,and pump function of left atrial strain all decrease with aggravation of diastolic dysfunction.The left atrial strain parameters show the potential for diastolic function evaluation in treadmill exercise stress echocardiography based on single parameters.