This week we take a closer look at the AV delay by exploring the differences between the paced and sensed AV delay while focusing on the importance of the law of AV conduction.

This week Dr Harry Mond revisits the well-known and researched ventricular interpolation with a review of the footprints and exceptions to the rule in a bid to teach something new.

Disagreement over the use of the terms “incomplete” or “partial” right bundle branch block (RBBB) had us take a deeper look at what is established in literature as an rSr’ pattern in V1/V2 with a QRS of 100 -120 ms, and when to call normal, normal!

Handed this ECG, we were asked if it was an example of a rate adaptive pacing, which uses changes in transthoracic impedance to increase the pacemaker rate in response to physiologic demand. Assoc Prof H Mond explains how to find the correct diagnosis.

This is one that is sure to spark conversation as a topic we know little about. Assoc Prof Harry Mond suggests some may even disagree with his view, and invites you not to hesitate to make some noise!

This Holter tracings showed a number of 2.8 second nocturnal pauses. A bundle branch block is also present. So the question was asked: Is this high degree AV block and does the patient need a pacemaker?

This week Dr Harry Mond reviews the ventricular ectopic compensatory pause with a focus on full and partial pauses while teaching us a lesson on timing.

After recently discussing the two most common variations of reversed arm and leg leads, we now explore combinations of Right Arm-Right Leg Reversed, including the double twists, & all the tell-tale footprints.

Last week some of you suggested dextrocardia in response to our case of reversed arm leads. This week shows that with dextrocardia the chest leads are very different and how to avoid misdiagnosis