The morphology of intracardiac electrograms (IEGMs) was used for pacem
aker patient workload estimation. The body posture also was studied as
another characteristic. The IEGMs were obtained and recorded via temp
orary transcutaneous leads connected to the implanted pacemaker. IEGMs
were recorded during exercise and at rest. Recordings at rest were pe
rformed in different body positions. The morphology was analyzed visua
lly in order to observe changes due to workload and posture. The recor
dings were digitized and processed by a computer-simulated neural netw
ork. The network was used as an automatic IEGM classifier based on the
morphology. Our results show that the morphology of the IEGM may be u
sed as an indicator of patient workload and body posture. The necessar
y information is found mainly in the ST segment. We conclude that neur
al networks seem to be useful in an active cardiac device.