Systems and methods for leadless pacing and shock therapy

A system comprising:

• a subcutaneous implantable cardioverter-defibrillator (SICD) configured to be implanted within a patient, wherein the SICD comprises:
• sensing circuitry configured to sense electrical signals associated with a heart of the patient;
• and
• processing circuitry configured to:
• detect, based on at least a portion of the electrical signals, a treatable rhythm;
• control the SICD to transmit, during a refractory period of a cardiac cycle, a communication message to a leadless pacing device (LPD), the communication message requesting that the LPD deliver anti-tachyarrhythmia pacing (ATP) therapy to the heart.

A method comprising:

• sensing, by sensing circuitry of a subcutaneous implantable cardioverter-defibrillator (SICD) configured to be implanted within a patient, electrical signals associated with a heart of the patient;
• detecting, by processing circuitry and based on at least a portion of the electrical signals, a treatable rhythm;
• and
• controlling, by the processing circuitry, the SICD to transmit, during a refractory period of a cardiac cycle, a communication message to a leadless pacing device (LPD), the communication message requesting that the LPD deliver anti-tachyarrhythmia pacing (ATP) therapy to the heart.

A system comprising:

• a lead including a plurality of electrodes and configured to be implanted within a patient;
• an implantable cardioverter-defibrillator (ICD) configured to be coupled to the lead and to be implanted within a patient, wherein the ICD comprises:
• sensing circuitry configured to sense electrical signals associated with a heart of the patient via at least one of the plurality of electrodes;
• and
• a signal generator configured to deliver electrical pulses via at least one of the plurality of electrodes;
• and
• processing circuitry configured to:
• detect, based on at least a portion of the sensed electrical signals, a treatable rhythm;
• control the signal generator to transmit, during a refractory period of a cardiac cycle, a communication message as one or more electrical pulses to a leadless pacing device (LPD) via at least one of the plurality of electrodes, the communication message requesting that the LPD deliver anti-tachyarrhythmia pacing (ATP) therapy to the heart.