Patent ID: 8504158

Claim:
A method comprising: estimating a length of a cardiac refractory period; and selectively adjusting a length of phrenic nerve electrical stimulation to be delivered to a patient based at least in part on the estimated length of the cardiac refractory period; and wherein estimating a length of the cardiac refractory period comprises estimating the length based at least in part on a cardiac signal of the patient; and, further comprising monitoring the cardiac signal; wherein: monitoring a cardiac signal comprises monitoring the cardiac signal over a plurality of cardiac cycles; estimating a length of a cardiac refractory period comprises updating the estimated length of the cardiac refractory period based at least in part on the cardiac signal monitored over the plurality of cardiac cycles; and selectively adjusting a length of phrenic nerve electrical stimulation comprises selectively adjusting the length of the phrenic nerve electrical stimulation based on the updated estimated length.