A young man with another episode of tachycardia. What is it? And why give adenosine in sinus rhythm?

Written by Bobby Nicholson MD and Pendell MeyersA man in his 30s presented to the ED for evaluation of chest pain and palpitations. He described it as a " jackhammering " sensation, associated with palpitations, diaphoresis, and shortness of breath, and he stated it started soon after consuming an " energy drink " (product/contents unknown).He stated these symptoms were the same as a prior episode which required cardioversion. He states that he has a heart condition which he does not know the name of and that he has felt his heart race like this once before and needed to be shocked. He was seen by a cardiologist in follow-up but was told he did not need routine follow-up.Here is his triage ECG:He had several more ECGs taken in the resuscitation bay over the next few minutes:What do you think?The ECGs show a wide complex, irregularly irregular tachycardia. The differential of wide complex irregularly irregular includes: polymorphic VT, atrial fibrillation with WPW, atrial fibrillation with other aberrancy. Closer examination shows polymorphic QRS complexes and multiple QRSs separated by 1 big box (200 msec) or even less. Thus, the patients rhythm is atrial fibrillation with WPW.With that in mind, how would you proceed with treatment?At this point, the patient had been symptomatic for almost 5 hours, appeared unwell with chest pain and diaphoresis. His blood pressure was 118/96. The team decided to start treatment with 1L of IV fluids, 4g of magnesium, and synchronize...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs