Patent ID: 7233826

Claim:
A method comprising: pacing a left ventricle in a first cardiac cycle; pacing a right ventricle in the first cardiac cycle; determining whether the pacing of the left ventricle is reliable in the first cardiac cycle; and pacing the left ventricle in a second cardiac cycle and inhibiting pacing of the right ventricle in the second cardiac cycle when the pacing of the left ventricle is determined to be reliable, wherein determining whether the pacing of the left ventricle is reliable comprises: testing an impedance of a left ventricular lead in a third cardiac cycle, wherein the third cardiac cycle precedes the first cardiac cycle; testing the impedance of the left ventricular lead during the first cardiac cycle; and determining that the pacing of the left ventricle is reliable when a magnitude of the impedance in the first cardiac cycle is substantially the same as a magnitude of the impedance in the third cardiac cycle.