Vice President Dick Cheney is to have his implantable cardiac defibrillator (ICD) battery changed. Actually, he'll have the whole device changed, with the exception of the leads - those will likely be re-used. It is a common misconception by patients needing an ICD battery change that only the battery is changed. The battery is housed with the capacitors and computer logic circuitry in one hermetically-sealed titanium can, to which the leads that extend to the heart are attached with small fixation screws. As such, the whole defibrillator can will be exchanged in a smae-say procedure.
It has not been publically discussed if Vice President Cheney has had some heart failure, or how much he uses his device to pace his heart. No doubt his doctors have considered if his device should be upgraded to a biventricular pacing defibrillator which can "resynchronize" and re-coordinate the heart's muscular contraction to improve symptoms of heart failure, since this would be an ideal time to do so while his device is exposed.
But usually with politicians eager to make light of the circumstances at hand, they usually opt for as little as possible (i.e., get in and get out) to minimize possible risks and media exposure. Hopefully, this will be the right decision.
As to which device he'll receive? Since he's had Medtronic devices previously, it's likely he'll receive a Virtuoso ICD this time around (which is a dual-chamber ICD that can be interrogated wirelessly). If his doctors should decide to upgrade his device to a biventricular ICD, then it would likely be with a Concerto ICD.