Use of external respiratory therapy device to detect cardiac electrical activity

1. A medical system, comprising:

an external respiratory therapy device configured to deliver an external respiratory therapy to a patient, the external respiratory therapy device including:

a respiratory event detector configured to detect respiratory events;

control circuitry configured to adjust the respiratory therapy based on the detected respiratory events;

one or more cardiac electrodes configured to sense cardiac electrical activity, the one or more cardiac electrodes located external to the patient;

circuitry, disposed within a housing of the external respiratory therapy device, configured to generate an electrocardiogram (ECG) signal based on the sensed cardiac electrical activity;

a cardiac event detector configured to detect cardiac dysfunction events based on the ECG signal; and

circuitry, disposed within the external respiratory therapy device housing, the circuitry configured to collect information based at least in part on the ECG signal, the collected information stored during each of multiple uses of the respiratory therapy device, the multiple uses corresponding to multiple sleep periods during which the patient uses the external respiratory therapy device; and

a processor located external to the patient and configured to analyze cardiac conditions of the patient over the multiple uses based on the collected information.

2. The medical system of claim 1 , wherein the cardiac event detector is configured to detect arrhythmia.

3. The medical system of claim 1 , wherein the processor is configured to develop a trend of one or more cardiac conditions related to heart failure.

4. The medical system of claim 1 , wherein the processor is configured to develop a trend of cardiac and respiratory conditions related to heart failure.

5. The medical system of claim 1 , wherein the processor is configured to determine relationships between the cardiac dysfunction events and the respiratory events.

6. The medical system of claim 1 , wherein the processor is configured to monitor progression of heart failure based on the collected information.

7. The medical system of claim 1 , wherein the processor is configured to diagnose cardiac disorders and respiratory disorders based on the collected information.

8. The medical system of claim 1 , wherein the ECG signals are not used to control the respiratory therapy.

9. The medical system of claim 1 , wherein the ECG signals are used at least in part to adjust the respiratory therapy.

10. The medical system of claim 1 , further comprising an implantable cardiac therapy device, wherein operation of the implantable cardiac therapy device is based at least in part on the ECG signal and the respiratory events.

11. The medical system of claim 10 , wherein the implantable cardiac therapy device is configured to deliver an electrical cardiac therapy to treat heart failure and delivery of the electrical cardiac therapy is based at least in part on the ECG signal and the respiratory events.

12. The medical system of claim 1 , further comprising an implantable cardiac therapy device, wherein operation of the implantable cardiac therapy device is based at least in part on the collected information.

13. The medical system of claim 12 , wherein the implantable cardiac therapy device is configured to deliver an electrical cardiac therapy to treat heart failure and delivery of the electrical cardiac therapy is based at least in part on the ECG signal.

14. The medical system of claim 1 , wherein the processor is further configured to determine heart rate variability based on the collected information.

15. The medical system of claim 1 , wherein the external respiratory therapy device is configured to cause another device to initiate delivery of a cardiac therapy based on detection of arrhythmia by the processor.

16. The medical system of claim 1 , wherein the control circuitry is configured to control delivery of the respiratory therapy based at least in part on the respiratory events and the cardiac conditions.

17. The medical system of claim 1 , wherein the external respiratory therapy device comprises a mask assembly, the external respiratory therapy comprises positive airway pressure that is delivered through the mask assembly, the one or more cardiac electrodes are mechanically coupled to the mask assembly, and the mask assembly is configured to hold the one or more electrodes against the patient during delivery of the external respiratory therapy to facilitate sensing of the cardiac electrical activity.

18. A medical system, comprising:

an external respiratory therapy device configured to deliver an external respiratory therapy to a patient, the external respiratory therapy device including:

means for detecting respiratory events;

means for controlling the external respiratory therapy based on the detected respiratory events;

means for externally sensing cardiac electrical activity;

means for generating an electrocardiogram (ECG) signal based on the sensed cardiac electrical activity;

means for detecting cardiac dysfunction events based on the ECG signal;

means for collecting and storing information based at least in part on the ECG signal, the information collected during multiple deliveries of the external respiratory therapy, the multiple deliveries corresponding to multiple sleep periods during which the patient uses the external respiratory therapy device; and

means for externally analyzing cardiac conditions of the patient based on the information collected over the multiple deliveries of the external respiratory therapy.