Simplify the following text for a Grade 14 native English-speaking person.
Original: Defibrillation is the definitive treatment for the life-threatening cardiac arrhythmias , ventricular fibrillation and pulseless ventricular tachycardia .
Simplified: Defibrillation is the act of defibrillating the heart to try treat ventricular fibrillation or pulseless ventricular tachycardia .