运动多普勒超声心动图评价二尖瓣位人工瓣血流动力学

Exercise Hemodynamics in Mitral Valve Prostheses by Doppler Echocardiography

目的：用多普勒超声心动图评价正常二尖瓣位人工瓣静态与运动血流动力学，为研究人工瓣功能异常提供基础资料。方法：用多普勒超声心动图观察测定５２例二尖瓣位人工机械瓣（１６例Ｓｔ．ＪｕｄｅＭｅｄｉｃａｌ瓣，１５例Ｍｅｄｔｒｏｎｉｃ－Ｈａｌ瓣和２１例Ｓｏｒｉｎ瓣）静态和运动后血流动力学变化。３种瓣心输出量及负荷量的差别无统计学意义（Ｐ＞０．４，Ｐ＞０．０９）。症状限制性卧位蹬车运动试验与多普勒血流参数记录同步完成。结果：跨瓣平均压差从静态０．６７±０．１４ｋＰａ（５±１ｍｍＨｇ）增加到运动１．６０±０．４０ｋＰａ（１２±３ｍｍＨｇ）。有效瓣口面积Ｓｔ．ＪｕｄｅＭｅｄｉｃａｌ瓣大于Ｍｅｄｔｒｏｎｉｃ－Ｈａｌ和Ｓｏｒｉｎ瓣并有极显著差别（Ｐ＜０．００１），而Ｍｅｄｔｒｏｎｉｃ－Ｈａｌ瓣与Ｓｏｒｉｎ瓣之间无统计学意义的差别（Ｐ＞０．１）。静态与运动后平均压差呈线性弱相关（ｒ＝０．４１，Ｐ＜０．０１，ｓｘ＝２．１，ｎ＝５２）。静态平均压差与心率呈弱性正相关（ｒ＝０．４５，Ｐ＜０．００１，ｓｘ＝０．９９，ｎ＝５２）。运动后平均压差的增值与左心室射血分数及负荷量呈正相关（ｒ＝０．６２，分别为：Ｐ＜０．００１，Ｐ＝０．００１，ｓｘ?

Objective:Exercise Doppler echocardiography was used to assess the hemodynamics in 52 patients with mitral prostheses.Sixteen had St.Jude Medical,fifteen had Medtronic Hall and twenty one had Sorin valves. Methods:A symptom limited supine bicycle exercise test was performed,and Doppler gradients were recorded during exercise. Results:Heart rate increased from 84±11 at rest to 140±19 beats/min after exercise and the mean gradient from 0 67±0 14 kPa(5±1 mmHg) to 1 60±0 40 kPa(12±3 mmHg)( r =0 41, p <0 01).The correlation of the mean diastolic pressure gradient after exercise with left ventricular ejection fraction(%) was 0 50.The increase value of the mean gradient after exercise was correlated with left ventricular ejection fraction (%) and workload ( r =0 62, p <0 001 and p =0 001). Conclusion:The gradients at exercise in patients with mitral prosthetic valves depend partly on the gradients at rest,and are affected partly by left ventricular ejection fraction (%) and workload.