An Adolescent with dizziness and near syncope

Submitted by Maura Corbett, PA-C, written by Alex Bracey, with some comments by Smith and MeyersA teenage male presented to the emergency department with the complaint of dizziness with near-syncope. He was stable and able to provide a history and mentioned that he was asymptomatic while seated but dizzy and weak when attempting to stand. An ECG was recorded:What do you think? There iscomplete (third degree) heart block with wide complex bradycardicescape.  The morphology is that of LBBB and so the escape is originating from the right bundle.The possible etiologies of this ECG are:- Structural/congenital heart disease- Wolff-Parkinson-White- Drug toxicity - Myocarditis- Infection resulting in conduction aberrancy (e.g., Lyme, rheumatic heart disease)- Hyperkalemia- Occlusion Myocardial Infarction (OMI) - Pacemaker dysfunctionOn further questioning, he recalled having several large, " bull ' s eye " rashes on his back approximately 3 weeks prior that had now resolved. A bedside echo revealed normal EF and no pericardial effusion. In this case, what is the likeliest cause of this conduction abnormality?The answer is Lyme disease causing Lyme carditis. (I texted the ECG to Dr. Smith with only the information that it was an adolescent patient to which he responded: " Lyme. " )This patient was seen in an emergency department in the Northeast, in which Lyme disease is endemic. Lyme disease itself is caused by the spirocheteBorrelia burgdorferi and...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs