EKG pattern different sitting than lying?

[EdZ314]

I have a portable 3-lead ECG/EKG monitor. When sitting up the reading has a completely different shape than when lying down. The spacing between the what is normally the peak (I think this is the R wave) and the next spike (the T wave?) is much shorter when sitting up and has a different shape. Is this normal?

[kenkeith]

Yes, when lying down and relaxed there is a different wave pattern, and it is normal for faster heart beat to have a tighter representation of R-T segment...also, slight amplitude difference as well.  You may try to increase your heart rate when lying down, and you will see the difference.

[ed34]

Of course. The electrical activity will look different because your heart is working slightly harder when sitting up rather than laying down. You have the force of gravity to pump against.