What is interesting to note is that on the left, we have ventricular pacing with an SA interval of 180 ms during orthodromic stimulation, as the His activation occurs antegradely via the atrium. On the right, there is development of a left bundle branch block during the tachycardia, with a VA interval of 175 ms. The SA and the VA intervals remains unchanged because, due to the left bundle branch block, the tachycardia follows almost the same pathway as during right ventricular pacing.