Apparatus and method for detection of atrial fibrillation by ventricular stability and ventricular pacing

An implantable cardiac device comprising:

• means for applying pacing signals to a ventricle in a patient's heart;
• means for sensing intrinsic ventricular signals in the ventricle;
• means for determining ventricular rate instability based on said ventricular signals;
• means for controlling said pacing signals;
• and
• classifying means for classifying said ventricular instability as corresponding to one of atrial fibrillation and ventricular tachycardia from a response to said pacing signals.

A cardiac implant device comprising:

• sensing means for sensing cardiac activity in a patient's heart;
• pacing means for generating cardiac pacing pulses;
• and
• control means for controlling said pacing means in accordance with said cardiac activity, said control means including cardiac classifying means for classifying a cardiac condition of the patient's heart, said cardiac classifying means including means for monitoring a ventricle to sense a ventricular rate instability;
• said control means being provided to pace said ventricle at a rate selected to stabilize said ventricle, said classifying means classifying said cardiac condition as atrial fibrillation, if said pace stabilizes said ventricle.

A cardiac implant device comprising:

• means for monitoring a ventricle to detect ventricular instability;
• means for selectively pacing said ventricle to attempt to reduce said ventricular instability;
• and
• means for classifying a cardiac condition based on a response to said pacing, said means for classifying generating information indicative of atrial fibrillation if said ventricular instability is reduced by said pacing.

An implantable cardiac device comprising:

• means for applying pacing signals to a ventricle in a patient's heart;
• means for sensing intrinsic ventricular signals in the ventricle;
• means for determining ventricular rate instability based on said ventricular signals;
• means for controlling said pacing signals;
• and
• classifying means for classifying said ventricular instability as corresponding to one of atrial fibrillation and supraventricular tachycardia from a response to said pacing signals.