RBBB, LAHB, Junctional rhythm

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RBBB, LAHB, Junctional rhythm

RBBB with LAHB & Junctional rhythmRBBB with LAHB & Junctional rhythm: ECG shows a slow regular rhythm with a ventricular rate of around 43/min. Though there are some baseline artefacts, no definite P waves or fibrillary waves are seen. If the baseline artefacts are considered as fibrillary waves, then it has to be considered as atrial fibrillation with complete heart block and a junctional escape rhythm. If the baseline artefacts are ignored, it becomes a pure junctional rhythm.

Alternate possibility in view of the tall peaked T waves (pink arrows) is an atrial paralysis with sinoventricular conduction in hyperkalemia.

Other findings in the ECG are left axis deviation with rS pattern in inferior leads suggesting left anterior hemiblock (LAHB) and qR pattern in V1 and a slurred S in V6 indicating right bundle branch block (RBBB). These two together constitute a bifascicular block. T wave is inverted in aVL. qR pattern in I and aVL also go with left anterior hemiblock. The difference in pattern between two QRS complexes in V1 is difficult to explain. T wave inversion in V1 and V2 can be secondary repolarization abnormality due to change in depolarization sequence due to right bundle branch block (secondary T wave abnormality). Arrow head T inversion in aVL seems to be a primary repolarization abnormality (primary T wave abnormality).