倾斜试验配合心得安试验对心血管疾病的诊断价值

Diagnostic value of tilt table test plus propranolol test in cardiovascular diseases

目的对功能性和器质性Ｔ波异常者倾斜前后Ｔ波改变的不同表现及对心得安试验阳性率，结合冠状动脉（冠脉）造影血管病变的严重程度加以分析。方法采用ＤＴ－１型自动倾斜床测定倾斜前后心率，血压及１２导联心电图及其服用心得安以后的变化。对器质性Ｔ波异常、功能性Ｔ波异常及对照组三组进行比较。结果（１）功能组心得安阳性率为８５％，器质组心得安阳性率为１５％（Ｐ＝０．００００）；（２）功能组心得安试验阳性倾斜前后心率均明显高于对照组（Ｐ＝０．０１６、０．００２），服用心得安２小时后平卧及倾斜后的平均心率均明显低于用药前（Ｐ＝０．０００）；（３）功能组心得安试验阳性服用心得安２小时后平卧位ＱＴｃ值明显小于服药前（Ｐ＝０．０１９），器质组心得安试验阴性服用心得安２小时后ＱＴｃ值与用药前无明显变化（Ｐ＞０．５）；（４）功能组倾斜后Ｔ波异常加重，服用心得安后明显改善，器质组倾斜后Ｔ波伪改善，心得安无效。结论功能性Ｔ波异常与β受体应答性的改变有关。

Objective To investigate the pathophysiologic mechanism of functional and organic T wave abnormality during standing position and with propranolol test. Methods Heart rate, blood pressure and 12 lead ECG were measured with DT 1 automatic tilt table. The changes of T wave in organic, functional and control groups were compared. Results (1) The positive rate of propranolol test in the functional group and organic group was 85% and 15% respectively ( P =0.0000). (2) The heart rate before and after standing was higher in the functional group with positive propranolol test than that in the controls ( P =0.016,0.0002). After oral propranolol, the heart rate before and after standing was lower than that of baseline ( P =0.000). (3) After oral propranolol, QTc in lying position in the functional group with positive propranolol test was shorter than that of baseline ( P =0.019). However, there was no change of QTc in the organic group with negative propranolol test as compared with that of baseline ( P >0.5). (4) T wave changes in the functional group became more significant in standing position and the T wave changes improved after oral propranolol. In the organic group, T wave changes were falsely improved in standing position and not improved with propranolol. Conclusion Functional changes of T wave were related to the change of β receptor response. Organic abnormality of T wave was related to the imbalance of β receptor distribution in the ischemia heart muscle and partial recovering of the sensitivity to sympathetic simulation.