A 50s year old man with lightheadedness and bradycardia

 Written by Pendell Meyers with edits by Smith and GrauerA man in his 50s with history of end stage renal disease on dialysis, prior bradycardia episode requiring transvenous pacemaker, diabetes, and hypertension, presented to the ED for evaluation of acute onset dizziness and lightheadedness starting several hours prior to arrival. These symptoms prevented him from going to dialysis, and his last session was three days ago. EMS found him with a heart rate of 30 bpm but normal blood pressure. He received 0.5 mg atropine with increased in heart rate to the 60s with improvement in symptoms. He denied chest pain or shortness of breath. Here is his triage ECG at 1533:There is a regularly irregular rhythm with RBBB and possibly also LAFB morphology. The T waves are definitively peaked in many leads. The rhythm is possibly junctional with pauses or block, I ' m not exactly sure. I asked Ken Grauer for help with this rhythm and he agrees it cannot be atrial fibrillation due to the irregular regularity, but with the artifact present also cannot definitively find atrial activity. His bottom line: " This rhythm is not ' following the rules ' - so either hyperkalemia - or some other toxicity - or very severe and diffuse conduction system disease producing junctional escape with bifascicular block with some complex form of exit block. " See his full comments reproduced at the end of the post. This ECG is diagnostic of significant hyperkalemia.He was immediately given ...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs