An Unusual Bradycardia

==================================Case Presentation by KEN GRAUER, MD (5/5/2023):   — Edits by Drs. Meyers& Smith ...==================================Dr. Smith was reading ECGs — and he sent myself and Dr. Meyers the tracing shown in Figure-1. At the time we did not yet know the history ...What do YOU think?Figure-1: The initial ECG in today ' s case. No history yet ...Our Initial Thoughts on the ECG in Figure-1:Dr. Meyers said the following:  " I see 2 different atrial foci — one sinus and one ectopic. There is AV block — but unclear why. T waves in leads V4-thru-V6 appear peaked — so possible hyperkalemia. "My Thoughts: I was struck by the unusual shape of deflections that I labeled a, b, d, e, and h — and by the fact that despite the high amplitude of deflection b in leads II and III, there was no deflection at all corresponding to b in lead I (See Figure-2). In addition — the amplitude of deflection d in leads aVR and aVL was approximately 1/2 the amplitude of d in lead aVF. These mathematical relationships of relative deflection size with absence of any deflection at all in lead I — are most commonly encountered when there is some type of artifact caused by movement or other interference originating from the Left Leg.I thought the lack of any QRS complex after deflections&n...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs