I have constant pvc's. while i was hooked up, my heartrate was 36 bpm and the ekg showed 100 bpm. thedoctor said that two beats at the same time was causingthe discrepancy. thoughts?

Non-conducted PVC: A pvc, or premature ventricular contraction happens when an electrical impulse that starts in the ventricles (lower chambers of the heart) instead of starting in the atrium (upper chambers). The impulse generated by the PVC doesn't always cause a physical contraction but may be visible on your ekg. This may be causing the discrepancy between the physical rate of 36 and the electrical rate of 100.

EKG is right: Pvcs don't transmit a pulse to the peripheral arteries so if you take your pulse at the wrist, arm or leg, you won't feel them and won't count them. The ekg, on the otherhand, shows all electrical activity thus the count from the ekg is the correct one.

Nonpulsatile beats: I saw your other question. This makes it more complete. Yes, pvcs occurring close to a regular beat don't pump much blood, so there's nothing for the pulse-oximeter to measure, hence it counts only the beats creating a strong pulse. That's the discrepancy he was referring to.