多巴酚丁胺对心肌梗塞后二尖瓣返流的作用

THE EFFECTS OF DOBUTAMINE ON MITRAL REGURGITATION AFTER MYOCARDIAL INFARCTION

目的：探讨不同剂量的多巴酚丁胺对心肌梗塞（ＭＩ） 后二尖瓣返流（ＭＲ） 的作用。方法：２３ 例心肌梗塞后二尖瓣返流者，分别给予２－５，５ ，１０ μｇ／ｋｇ·ｍｉｎ 的多巴酚丁胺静脉注射，彩色多普勒超声心动图测量不同剂量下二尖瓣返流面积、左室射血分数（ＬＶＥＦ）、左室舒张末直径（ＬＶＥＤｄ） 、二尖瓣血流Ｅ 峰和Ａ 峰流速，计算心率－ 收缩压乘积并观察副作用发生情况。结果：多巴酚丁胺的剂量在２－５ μｇ／ｋｇ·ｍｉｎ 时使心肌梗塞后ＭＲ 的返流量从（２－６２ ±２－４９）ｃｍ２减至（１－８９±２－９４）ｃｍ２ ；ＬＶＥＤｄ 从（５－６６±０－６４）ｃｍ 减至（５－０５ ±１－１６）ｃｍ（ 分别Ｐ＜ ０－０５） ；ＬＶＥＦ 从（４２－８ ±１２－５）％增加至（４６－６±１３） ％（ Ｐ＜０－０１）。随剂量增加上述作用明显增强，不同剂量级相比前两者分别Ｐ＜ ０－０５ ，后者Ｐ＜０－００１ ；对Ｅ峰流速及Ｅ／Ａ 比值均无明显影响（Ｐ＞ ０－０５），但在１０μｇ／ｋｇ·ｍｉｎ 剂量级二尖瓣Ａ峰流速明显增高（Ｐ＜０－０５）；５μｇ／ｋｇ·ｍｉｎ 剂量级心率－ 收缩压乘积明显增高（ Ｐ＜０－０１），１０μｇ／ｋｇ·ｍｉｎ 时影响更加显著（ 与５μｇ／ｋｇ?

To investigate the effects of different dose dobutamine on mitral regurgitation(MR) after myocardial infarction(MI).Methods:23 patients with MR after MI underwent comprehensive M-mode,two-dimensional and Doppler echocardiographic examination at rest and during dobutamine infusion at a dose of 2.5,5,and 10 ug·kg -1 ·min -1 .Left ventricular end-diastolic diameter(LVEDd),the MR area(MRA),left ventricular ejection fraction(LVEF),mitral inflow E wave and A wave velocities were measured at rest and every stage during dobutamine infusion.The arithmetic product of heart rate and systolic pressure was calculated and the side effects of dobutamine infusion was observed.Results:From rest to the does of 2.5 ug·kg -1 ·min -1 ,MRA decreased(2.62±2.49cm 2 vs 1.89±2.94cm 2, P <0.05),LVEDd decreased(5.66±0.64cm 2 vs 5.05±1.16cm, P <0.05),LVEF increased significantly (42.8±12.5% vs 46.6±13%, P <0.01).Stepwise increasing doses of dobutamine caused a significant increase of the above effects.The two former parameters were different( P <0.05 respectively) and the latter parameter was significantly different between different doses( P <0.001).There was no difference of E wave velocity and the ratio of E to A wave velocities( P >0.05 respectively).The rate-pressure product notably increased from rest to the dose of 5 ug·kg -1 ·min -1 ( P <0.01) and from 5 ug·kg -1 ·min -1 to the peak dose( P <0.001).No untoward effect occured in any of these studied patients.Conclusions:The results suggest that,in ordinary doses(2.5 ug·kg -1 ·min -1 ),dobutamine is a safe,effective agent for treating MR after MI since it not only improves MR,increases left ventricular systolic function but also doesn't affect left ventricular diastolic function.5 ug·kg -1 ·min -1 does of dobutamine infusion is suitable for the treament purpose. Key Words:Myocardial Infarction;Mitral Regurgitation;Dobutamine;Color Doppler chocardiographyof 86 eyes of successful rhegmatogenous retinal detachment with a higher encircling scleral buckle underwent A scan and keratometer examination before surgery as well as l week,4 and 12 weeks after surgery.The refractive factors included the depth of anterior chamber,thickness of lens,axial length of eye,corneal curvature and refraction of eye were detected pre and post operatively. Results Compared with preoperation,the depth of anterior chamber was decreased significantly at the lst,4th and 12th postoperative week(P<0.05),while no significant change of the axial length of eye was observed.The thickness of lens was increased significantly and the refractive error was myopic shifted at the lst and 4th week after operation(P<0.05),but no significant change was observed at the 12th postoperative week.Statistically significant difference was also observed in corneal curvature of central axis in the local buckle≤1 quadrant with encircling group between preoperation and the lst and 4th postoperative week. Conclusions With higher encircling scleral buckle,the refractive change after buckling surgery may be caused primarily by the shallowing of anterior chamber and thickening of lens.