Treating sleep apnea in patients using phrenic nerve stimulation

An implantable cardiac device comprising:

• an electrode adapted for placement on a patient's heart;
• implantable means for generating pulses to be applied via the electrode to the patient's heart;
• and
• implantable means for altering pulse widths of the pulses to produce first pulses, which when applied via the electrode, stimulate the patient's heart without stimulating the phrenic nerve, and to produce second pulses different from the first pulses, which when applied via the electrode, stimulate the patient's heart and phrenic nerve.

An implantable and programmable cardiac device having a memory and a processor, the cardiac device being programmed to perform tasks comprising:

• applying pacing pulses to pace a patient's heart;
• detecting when the patient is experiencing an episode of central sleep apnea;
• determining when the patient is in an inspiration phase of a respiratory cycle;
• and
• in response to the detecting and to the determining, selectively applying a phrenic nerve stimulation pulse to the patient's phrenic nerve to stimulate the patient's phrenic nerve to provoke respiration.

A method implemented by an implantable cardiac device, comprising:

• administering pacing pulses to a patient's heart;
• detecting when the patient is experiencing central sleep apnea;
• and
• in response to detecting the central sleep apnea, selectively applying phrenic nerve stimulation pulses to the patient's phrenic nerve, the phrenic nerve stimulation pulses having comparatively higher voltage and having comparatively shorter pulse widths than the pacing pulses.

A method comprising:

• determining that a patient is at rest;
• and
• while the patient is at rest,
• administering a rest mode pacing therapy of comparatively lower voltage pacing pulses effective to stimulate the patient's heart;
• detecting when the patient is experiencing an episode of sleep apnea;
• and
• in response to detecting the sleep apnea, administering sleep apnea pacing therapy of comparatively higher voltage phrenic nerve stimulation pulses that are effective to stimulate the patient's phrenic nerve to provoke respiration.