I think i have experienced pvcs but the episode has lasted for a few hours (and then went away). do pvcs last this long?

PVCs: This requires a physical examination and tests. Self diagnosis is not reliable. You need a cardiac evaluation. See your doctor asap.

Somewhat atypical: Its a bit abnormal for PVCs/palpitations to last for hours. Almost everyone has PVCs here and there but a period lasting that long should prompt a review with your primary care provider. While it isn't abnormal for people to have PVC and is mostly considered benign, there are sometimes primary heart and other issues that can cause this. The episode you felt may not even be PVCs.

Sometimes: Its possible to have frequent PVCs lasting several hours. Its imprtant to understand that PVCs themselves aren't harmful as long as you have been evaluated by a physician for other conditions. Typically some form of extended EKG monitoring (like a holter monitor) is performed to ensure that there are no other arrhythmias.