{HEAD ~ Also, stimulation} at {TAIL ~ a physiological back up frequency} is provided in the event of a detected ventricular pause 
at
{ HEAD ~ Also , stimulation } at { TAIL ~ a physiological back up frequency } is provided in the event of a detected ventricular pause
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH