Automatic mode switch funtion was observd in 6 patients in response to atrial fibrillation,lasting from 1 min to 3 time,and inverted into DDI 10 patients sinoatrial node badness was observation.

• 6例发生房颤,持续时间1min至3h不等,均转为DDI模式; 观察到窦房结变时性功能不良10例;