Para-Hisian accessory pathway (AP) means the AP locate about 0. 5cm above or under the His bundle. To identify the AP location,the big tip catheter mapping must be under sinus rhythm,ventricular pacing and inducing SVT in order to avoid injury of His bundle. During ablation process, the surface morphology and juctional escape rhythm must be observed. If RF must be done under ventricular pacing, once ablating effect is confirmed,the pacing would be stopped and escape rhythm can be observed. If ante-grade condution are always through AP in SVT and endocardial mapping are confirmed multipe APs and AVN are bystander in SVT, we do not exclude abmormal growth in AVN. It can be ablated retrograde AP to treat SVT and should be avoided to ablate antigrade AP.

Objective:To evaluate the value of ultrasound Doppler renal blood flow measurement in diagnosing early renal damage of hypertension. Methods:Eighty patients with hypertension and 20 normotensive subjects were included in this study. They were classified into four groups according to blood or urine β2-MG contents and urinary albumin excretion rate(UAER). All patients were measured by ultrasound Doppler renal blood flow. Correlation analysis was performed between β2-MG or UAER and the parameters of renal blood flow measurement. Results:(1)Peak velocity in systole(Vs)、end diastolic velocity(Vd) decreased and pulsed index(PI)、resistance index(RI) of segmental and interlobar artery increased in all hypertensives with early renal damage. PI of interlobar artery more than 1.00 and/or RI more than 0.60 is associated with early renal damage in hypertensives;(2)Hypertensives with diabetes and early renal damage have higher Vs and lower Vd and significant increased RI、PI. Compared with hypertensives with early renal damage，hypertensives with diabetes had more serious renal damage at the equivalent DBP level. Conclusion:Ultrasound Doppler renal blood flow measurement may be clinically useful in the noninvasive evaluation of early renal damage of hypertension.