I just transported an 83y/o lady w/ this....it was a first for me too. They initially called it 2nd deg HB, but it didn't really fit. There was a normal beat (PRi=.24), followed by another with the same PRi, but starting almost on top of the T wave. The couplet was followed by a P wave and dropped QRS. The dropped QRS i suppose is the compensatory pause ...just the atria forgot to pause:).