They can be caused by abnormal automaticity, reentry, or a triggered afterdepolarization.
可以由异常自律性、折返激动或被激发的后除极引起。
英语百科
Afterdepolarization
Afterdepolarizations are abnormal depolarizations of cardiac myocytes that interrupt phase 2, phase 3, or phase 4 of the cardiac action potential in the electrical conduction system of the heart. Afterdepolarizations may lead to cardiac arrhythmias.