Patent ID: 8447390

Claim:
A method comprising sensing an atrial activation of a subject; detecting that a tachyarrhythmia is present in the subject; comparing a characteristic of the atrial activation present just before the tachyarrhythmia was detected to a characteristic of the atrial activation during the detected tachyarrhythmia, wherein comparing includes: determining a difference between an atrial rate variability present just before the tachyarrhythmia was detected to an atrial rate variability during the detected tachyarrhythmia; and comparing the difference to a threshold value; and using the comparison to determine a hemodynamic stability characteristic of the tachyarrhythmia, wherein determining the hemodynamic stability characteristic includes: when the difference is above the threshold value, declaring that the tachyarrhythmia is hemodynamically stable; and when the difference is below the threshold value, declaring that the tachyarrhythmia is hemodynamically unstable.