Cardiac activity is controlled by the autonomic nervous system and is thus commonly se ed only by perso with a ormally heightened awarene of their body functio , eg, in anxiety states.

• 心脏活动受自主神经系统控制，因此，通常也只有对身体功能高度异常敏感的人才常会感觉到，如忧虑状态病人。