Methods : 60 patients with VVS were divided into two groups basic TTT ( BTTT ) and sublingual ISON adminstration before TTT ( TTT + ISDN ) .
方法：将60例血管迷走性晕厥患者分成基础倾斜试验（BTTT）组和ISDN舌下含服激发倾斜试验（TTT加ISDN）组。
bttt