R指数评价静息状态下动力型左室腔流出梗阻的价值及其临床意义

Value of R index in evaluation on dynamic intraventricular obstruction of left ventricle at rest and its clinical significance

目的:通过常规超声心动图总结静息状态下动力型左室腔流出梗阻(DIVO)心动图特征,并根据其特点设计一个新的指标R指数(狭窄处等容舒张期流速/左室主动舒张峰速度),探讨R指数定量评价DIVO的价值。方法:选取以胸痛、胸闷就诊的DIVD患者112例(梗阻组),同时选取50名健康者作为健康对照组。采用常规二维超声心动图获取研究对象左室收缩末径(LVESD)、左室舒张末径(LVEDD)、间隔上部厚度(U-IVS)、中部厚度(M-IVS)和左室射血分数(LVEF)。彩色多普勒超声获取左室腔流速(流出道流速、左室中部流速和左室心尖部流速)。在心脏各切面观察左室心肌运动和左室腔内彩色血流,并测量收缩末期左室腔最窄处内径,于血流汇聚处获取平静呼吸及Valsalva试验下的等容舒张峰峰速、左室主动舒张峰E峰峰速及R指数,绘制受试者工作特征曲线(ROC),计算曲线下面积(AUC),根据约登指数确定R指数的诊断界点。结果:与健康对照组比较,梗阻组患者心率偏快,血压偏高(P<0.01)。梗阻组患者二维超声心动图特征表现为左室心肌运动活跃,心腔相对偏小,且可见几何形变;DIVO患者左室腔内正常流速梯度趋势发生改变,收缩期血流频谱呈峰值后移,于等容舒张期可见等容舒张峰,且等容舒张峰速明显快于健康对照组(P<0.01),R指数明显大于健康对照组(P<0.01)。结论:DIVO患者R指数明显增大,且R指数≥1可作为静息状态下DIVO患者特异性诊断指标。

Objective：To summarize the echocardigraphic characteristics of dynamic intraventricular obstruction（DIVO）of the left ventricle by traditional echocardiography at rest and to design a new index（R index,VIVR/VE）according to its characteristics,and to explore the value of R index in quantitative evaluation on DIVO.Methods：One hundred and twelve patients with DIVO were chosen as obstruction group.All patients had chest pain or dyspnea.A total of 50 healthy volunteers were used as healthy control group.The left ventricular end-systolic diameter（LVESD）,left ventricular end-diastolic diameter（LVEDD）,upper interventricular septum thickness（UIVS）,middle interventricular septum thickness（M-IVS）and left ventricular ejection fraction（LVEF）were obtained by two-dimensional echocardiogram.The maximal systolic velocities and gradients at the left ventricular outflow tract（LVOT）,mid-ventricle and the apex of left ventricle were obtained at rest in all patients using color Doppler ultrasound.The myocardial movement and the flow of left ventricle were observed at different aspects.Then the velocity of E wave,the narrowest inner diameter,the systolic velocity,the velocity of isovolumic relaxation（VIVR）and R index of the narrowest part were obtained.The receiver operating characteristic（ROC）curve was builded and the area under curve（AUC）was calculated.An index about confirmed the diagnosis of R index point was obtained.Moreover,the specificity and sensitivity of R index for the diagnosis of DIVO of the left ventricle at rest was explored.Results：The heart rate of patients with DIVO in obstruction group was faster than that in healthy control group and the blood pressure was higher than that in healthy control group（P〈0.01）.The2 Dechocardigraphic characteristics of the DIVO patients showed that the myocardial movement of left ventricle was enhanced.The left ventricle diameter of the DIVO patients in obstruction group was smaller than that in healthy control group,and the shape of the left ventricle was irregular.As for Doppler,the normal flow velocity gradient in the left ventricular of the patients with DIVO was changed.A Doppler spectrum with peak value moving forward was found in obstruction group,and a IVR wave was seen,and the velocity of IVR wave was faster than healthy control group（P〈0.01）and the R index was enlarged obviously（P〈0.01）.Conclusion：The R index of DIVO patients enlarges significantly,and R index ≥1is the specific diagnosis indicator of the DIVO patients at rest.