So, sudden cardiac death is firstly a sudden event. Whether there are sequelae depends greatly on whether timely rescue was administered at the time of the cardiac arrest. If effective cardiopulmonary resuscitation is given within a short time, generally within 4-6 minutes, then the patient's vital signs including consciousness might gradually recover, and it's possible that no severe sequelae will remain. However, if the rescue is not timely, it's possible for the heartbeat and breathing to be restored but not consciousness, leading to brain death and a vegetative state. This is a possibility.