Abstract: Systems and methods provide for sensing, within a patient and during an event of tachycardia, a signal indicative of a mechanical response of the patient's heart to the tachycardia. Regularity of the signal relative to a threshold established for the patient is determined. A state of patient hemodynamics during the tachycardia event is determined based at least in part on the regularity of the signal. One or more anti-tachycardia therapies to treat the tachycardia may be selected based at least in part on the determined state of patient hemodynamics. The selected one or more anti-tachycardia therapies may be delivered to treat the tachycardia.

Abstract: Systolic timing intervals are measured in response to delivering pacing energy to a pacing site of a patient's heart. An estimate of a patient's acute response to cardiac resynchronization therapy (CRT) for the pacing site is determined using the measured systolic timing intervals. The estimate is compared to a threshold. The threshold preferably distinguishes between acute responsiveness and non-responsiveness to CRT for a patient population. An indication of acute responsiveness to CRT for the pacing site may be produced in response to the comparison.

Abstract: Methods and systems provide an approach to therapy control based on assessment of a patient's cardiopulmonary status. Conditions sensed via sensors of an external respiratory therapy device are used to assess a patient's cardiopulmonary status. The respiratory therapy device sensors may be utilized alone or in combination with other sensors to determine cardiopulmonary status of a patient. Therapy delivered to the patient is controlled based on the cardiopulmonary status assessment. For example, therapy delivered to the patient may be initiated, terminated, and/or modified based on the assessed cardiopulmonary status of the patient. Cardiopulmonary status assessment, therapy control, or both, are performed by an implantable device.