Pvc during/after exercise

last month I was doing some exercise on the elleptical. I was about 30 minutes in to my routine, sweating and breathing at a high rate...when I quit my exercise routine, Suddenly I felt my heart was skipping, it felt like it was  skipping/ missing  every other beat rapidly. I ried to catch my breath but I think I panicked and my heart didnt return to normal until 60 seconds or so. it was quite terrifying... what was this all about?I've had a holter, but I didn't get this rhytem while wearing. Only 2 pvc's where catched. Also I've had an echo with no abnormalities. I am male 25 years of age.. healthy and athletic overall (or so i thought? )

I think there where pvc's but the jolt sensation  felt  extremely worse, like my breat was taking away every other beat. My questions:

1. What is the significance of pvc's during or after exercise at a heart rate of 140/150 beats per minute? (in young men)

2. I had about 16 pvc's in a minute and then it stopped, how much pvc's are normal at this heart rate?

3. Should I do more tests, because of the fact the rhytem was not catched on the holter.

Thanx doc.