Ectopic atrial rhythm at a rate of 70 beats per minute. P waves are clearly seen and negative in several leads, indicating they do not originate from the sinus node but rather a low atrial region, consistent with an ectopic atrial rhythm. There is also an incomplete right bundle branch block present as shown by a prolonged QRS duration with an rSR' pattern. The final diagnosis is an ectopic atrial rhythm at 70 beats per minute with an incomplete right bundle branch block.