Rhythm is regular (relatively narrow) with rightward QRS axis around +100-110. Q waves anteriorly suggestive of possible old anteroseptal MI. It will be helpful to see an older EKG, so axis can be compared as it is uncommon to see this rightward axis at this age, and if this is significant the shift can be assumed due to left posterior fascicular block. 

QRS are not preceded by immediate P waves, but there is consistent P waves seen in the ST segment of prior beats with PR interval over 500 ms. The morphology of these P waves in inferior leads are not very clear to discern if they are antegrade or retrograde, but they are likely antegrade (given their width). In which case, the rhythm is sinus with very long PR interval making atrial kick likely occurring during prior ventricular systole; hence can explain the patient's SOB (with data to support PM implantation will improve symptoms). 

At the bedside, it will be interesting to see regular "Cannon" waves on JVP evaluation.