Ventricular tachycardia
If a person goes into pulseless ventricular tachycardia, first aid can be helpful.  9-1-1 or the local emergency telephone number should be called immediately.  Then - like in any situation where a person suddenly becomes unconscious and has no pulse - cardiopulmonary resuscitation (CPR) should be started right away.  An emergency medical dispatcher can help explain how to do CPR until an ambulance gets there.