Patent ID: 8024040

Claim:
A method for operating a cardiac rhythm management device, comprising: sensing ventricular depolarizations and generating ventricular sense signals in accordance therewith; deriving a ventricular rate as a function of a plurality of time intervals between successive ventricular senses; detecting a ventricular bradycardia when the derived ventricular rate is below a specified bradycardia limit value; initiating delivery of one or more electrostimulation pulses to the ventricle while the ventricle is refractory when ventricular bradycardia is detected from the derived ventricular rate to thereby increase the contractility of the ventricle, wherein such electrostimulation pulses are timed to occur within a refractory interval following a ventricular sense or pace; pacing the ventricle upon expiration of an escape interval without receipt of a ventricular sense, the inverse of the escape interval being the lower rate limit; and, increasing the lower rate limit when bradycardia is detected.