Gradually synchronized simultaneous atrial and ventricular pacing for cardiac rhythm discrimination

A computer-readable medium programmed with instructions for delivering anti-tachycardia pacing, the medium comprising instructions for causing a programmable processor to:

• monitor patient parameters in an atrium and a ventricle to detect a tachycardia;
• deliver pacing pulses to the atrium and the ventricle each pacing cycle upon detection of the tachycardia, one or more initial atrial pacing pulses being delivered out of phase with corresponding one or more initial ventricular pacing pulses;
• and
• gradually shift the phase difference between the pacing pulses delivered in the atrium and the ventricle over a quantity of pacing cycles until the pacing pulses are delivered together in phase each pacing cycle.

A method of providing simultaneous atrial and ventricular pacing, comprising:

• monitoring patient parameters in an atrium and a ventricle;
• detecting an abnormal or suspected abnormal heart rhythm in one of the atrium and the ventricle;
• determining whether delivery of simultaneous atrial and ventricular pacing pulses falls within vulnerable regions of the cardiac cycle;
• delivering pacing pulses to the atrium and the ventricle each pacing cycle, the atrial pulses being delivered out of phase with the corresponding ventricular pacing pulses if simultaneous delivery of such atrial and corresponding ventricular pacing pulses falls within vulnerable regions of the cardiac cycle;
• gradually shifting any out of phase atrial and ventricular pacing pulses relative to each other over a quantity pacing cycles until the pacing pulses are delivered in phase each pacing cycle;
• and
• delivering atrial and ventricular pacing pulses in phase.