OPM3444O Missing heartbeat detected CA ETA R12.1

Running without any problems and sometimes getting the error message 'Missing heartbeat'.
Why does this happen, why this message.

  OPM3444O Missing heartbeat detected CA xxx Rnn.n ETCL X'0078' 

And after some time you see

  OPM2211O Heartbeats resumed CA xxx Rnn.n ETCL X'0078'

The heartbeat process is done with API events from CA products. 

In addition to the State change API events, CA products (if they choose) can send us API events on a regular basis (Heartbeats) to let us know they are still working, the CA OPS/MVS monitor subtask will track these and report via the OPS34444O when we do not receive heartbeat API events for a product. 

In this case, it appears the whatever CA xxx is, that it may not have been functioning properly. 

Check the connection between your CA OPS/MVS environment (lpar) and the platform the CA xxx product is running at.

See if there is not connection loss, or network issue.