The lead 162 carries pacing and sensing electrodes 172, 174, for sensing {HEAD ~ ventricular depolarizations} and for pacing {TAIL ~ the heart} 
for pacing
The lead 162 carries pacing and sensing electrodes 172 , 174 , for sensing { HEAD ~ ventricular depolarizations } and for pacing { TAIL ~ the heart }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL