There is a predictable pattern of sinus beats followed by a pause creating group beats.The P-P interval during the pause has a duration that is approximately equal to two P-P cycles. All PR intervals are the same and QRS complexes follow all the P waves. These findings are consistent with type 2 sinoatrial exit block. Note that the pause duration in type I SA block l is less than two P-P cycles (in contrast to this ECG)