INTERPRETATION:
(1.)  Slightly irregular sinus bradycardia (48-53/min) with . . .
(2.)  . . . two unifocal ventricular premature beats (VPBs); the 1st VPB (3rd beat) being conventional and the 2nd VPB (7th beat) being interpolated with . . .
(3.)  . . . retrograde concealed conduction.

COMMENTS:
The first VPB is conventionally followed by a fully-compensatory pause.  The Both VPBs (V) are followed by identical RP intervals of about 0.46s. The first VPB has a coupling interval of about 0.54s and the second VPB has a slightly shorter coupling interval of about 0.51s. While its true that neither VPB conducts all the way back up to the atria, I would postulate that the first VPB does conduct further retrogradely into the A-V node leaving it more refractory than the second VPB which probably doesn't conduct as far backwards (see laddergram). Since the second VPB doesn't travel backwards as far, this leaves the A-V node somewhat less refractory so that conduction is possible but still delayed.  Compare the P-R interval on the 8th beat to P-R interval (0.28s) on the 2nd beat (0.20s). In other words, the duration of the VPB's preceding coupling interval is directly proportionate to the amount of retrograde concealed conduction it exerts on the A-V junction. The reason the RP intervals are identical despite the non-fixed coupling intervals is because the sinus cycle shortens (119 to 116) by the same amount that the coupling interval shortens (54 to 51) with a difference of 3 for both. Interpolated VPBs are much more likely to be seen in sinus bradycardia than in either sinus rhythm or sinus tachycardia.  As far as the deep Q-wave in lead III that Vince mentioned, I'll have to investigate the significance of that and update this post in the near future.