I pulled this explanation from a college website:
"Very short PR intervals are seen in patients with pheochromocytoma and in patients with Wolfe-Parkinson-White Syndrome. Ocassionally, individuals with normal hearts will have very short PR intervals as a normal variant. Prolonged PR intervals are seen in individuals with 1st degree AV block, 2nd degree AV block (Mobitz I), and in patients with rheumatic heart disease"
I would ask your Dr. to explain the finding and inquire if any further testing is required. Basically the short PR could be nothing, it could be something but the EKG alone is not enough to answer the question. Best of luck.
Here is a recent post on short PR, it may help answer your question.
http://www.medhelp.org/posts/show/424503
What did your doctor say?