At a subsequent syncopal attack, 24 hours ambulatory ECG was repeated and found intermittent complete atrioventricular block with prolonged ventricular asystole up to 19.4 sec.

• 重覆第二次的廿四小时心电图检查才发现间歇性房室传导完全阻断，最久的心跳停止时间长达19.；4秒。