A hierarchical approach to the treatment of ventricular tachycardias

Electrical management of ventricular tachycardias with an implanted device is greatly complicated by reduced hemodynamic tolerance to the tachycardia with increasing rate, and by the risk of accelerating the tachycardia into fibrillation. Pacing (extrastimuli, bursts), low-energy cardioversion, and high-energy defibrillation therapies are all useful in safely treating a ventricular tachycardia. A implantable device is described which allows the classification of up to four different arrhythmias each having their own detection criteria (including high rate, sudden onset, rate stability and sustained high rate). For each classified arrhythmia, up to four therapies may be programmed to be sequentially delivered. This scheme allows for increasing on the aggressiveness of the therapy based on elapsed time, increased rate, or both; and provides a large amount of flexibility for tailoring the desired therapies to individual patients.