扩张型心肌病患者主动脉弹性改变的初步研究

目的探讨扩张型心肌病（DCM）患者主动脉弹性改变。方法DCM患者33例,健康志愿者30例。所有受试者肱动脉血压测量之后即刻左侧卧位,连接心电图,行常规经胸超声心动图检查。M型超声分别测量升主动脉瓣上3cm处收缩期和舒张期内径,利用公式计算主动脉膨胀性（D）和僵硬度（β）。转入TVI模式在组织-速度曲线上测量升主动脉同处前壁的运动速度（Sao）。改良Simpson法测定左室射血分数（LVEF）。结果DCM组僵硬度增高（3.38±0.72vs.1.83±0.47,P〈0.01）,膨胀度降低（0.70±0.18）cm^2/dynesvs.（1.24±0.32）cm2/dynes,P〈0.01],升主动脉前壁S波运动速度降低（4.40±0.69）cm/svs.（6.45±1.29）cm/s,P〈0.01],差异均有统计学意义。DCM组与对照组中,年龄与主动脉僵硬度呈正相关（均P〈0.05）,与主动脉前壁S波速度和主动脉膨胀性呈负相关（均P〈0.05）;在DCM组,LVEF是主动脉前壁S波速度的另一重要影响因素（P〈0.01）。结论DCM患者主动脉弹性功能受损;年龄及左室射血功能是DCM患者主动脉弹性受损的重要影响因素。

Preliminary study of the influence of the aorta's elasticity in patients with dilated cardiomyopathy

Objective To evaluate factors which influence the elasticity of the proximal aorta in patients with dilated cardiomyopathy (DCM).Methods Thirty-three patients with DCM were selected,while 30 healthy volunteers were matched with DCM group in age and gender as control group.After measuring arterial pressure,all subjects were immediately examined by using conventional echocardiography at left lateral decubitus position and linking ECG at the same time.In addition,internal aortic systolic and diastolic diameters were obtained at 3 cm above the aortic valve with M-mode echocardiography.As a result,aortic distensibility (cm2/dynes) and aortic stiffness index were calculated by using formulas.In the view of ascending aortic tissue velocity imaging (TVI),ascending aortic upper wall tissue velocities (aortic S,cm/s) were measured 3 cm above the aortic valve (the same point as the former) on TVI curve.And left ventricular ejection fraction (LVEF) was calculated by modified Simpson's method.Results Compared to the healthy subjects,the aortic stiffness index of patients with DCM was significantly higher (3.38±0.72 vs.1.83±0.47,P<0.01),while aortic distensibility and aortic S velocity were significantly lower respectively (0.70±0.18)cm2/dynes vs.(1.24±0.32)cm2/dynes,P<0.01,(4.40±0.69)cm/s vs.(6.45±1.29)cm/s,P<0.01].For both DCM group and healthy group,positive correlation was found between age and aortic stiffness (P<0.05,both),and age was found to have significantly negative correlation with aortic S wave velocity and left ventricle ejection (P<0.05,both).Furthermore,in DCM group,left ventricle ejection was the other important factor which has influence on aortic S wave velocity.Conclusions Elasticity of aorta in patients with DCM has been damaged.Age and left ventricle ejection are the important clinical factors which would acceletate the process of reducing the elasticity of aorta in patients with DCM.