An exercise in thinking outside the box.‍ What do you think?

Last week I presented a series of ECGs on dual AV nodal pathway physiology. In one ECG, I missed another form of dual AV nodal pathway physiology, which allows the creation of echo beats. Let us revisit the ECG as I presented it.

I was asked for an opinion regarding this ECG. The reporting doctor had requested a repeat ECG.‍ Patient has a pacemaker. What do you think?

Dr Kianseng Ng from Malaysia recently sent me this ECG and the only information was that he thought the patient had a pacemaker.This is a continuous rhythm strip for 60 seconds and the format is extremely difficult to visualize. What do you think?

I was shown this ECG this week. There are two ectopic beat configurations labelled “S” for supraventricular and “V” for ventricular. The issue with the referring doctor was that they were mislabelled because the broad QRS is labelled supraventricular and the narrow QRS, ventricular. What do you think?

I was shown this pacemaker ECG this week. It appears to violate the law of AV conduction.‍ What do you think?

When I receive an ECG with a pacing rhythm, the report invariably states, “ventricular pacing” or “dual chamber pacing” with no attempt to interpret it. I saw this ECG and decided to use it as an example of how to interpret pacing ECGs. What do you think?

What do you think? Clue: Last week, I stated that maybe I would talk about interpolated ventricular ectopics this week.

I have presented this before, but it continues to bewilder people. Is this heart block? What do you think?