Complications from left ventricular assist devices (LVAD) increasingly account for Emergency Department visits. What are LVADs? They are a short-term, artificial, circulatory device which performs the function of a very poorly functioning heart. It is important to understand the myriad of complications that can arise and the general approach to patients with an LVAD. These two short videos by Dr. Rahul Patwari summarize these in a nutshell.
Door-to Balloon (D2B) time is a time measurement that starts with patient arrival to the emergency department (door) and ends when a catheter crosses a culprit lesion in the cardiac cath lab (balloon). The benefit of prompt primary percutaneous coronary intervention over thrombolytic therapy for acute ST elevation myocardial infarction is very well established. Because of this “time is muscle” strategy, the American College of Cardiology (ACC) launched a national Door to Balloon (D2B) initiative in November 2006. The purpose of this was to recommend a D2B time of no more than 90 minutes. Currently, there is quite a bit of effort put into this guideline by cardiology and emergency medicine, but are we measuring the right thing?
Troponin testing is an important component of the diagnostic workup and management of acute coronary syndromes (ACS). The increasing sensitivity of troponin assays has lowered the number of potentially missed ACS diagnoses, but this has also created a diagnostic challenge due to a decrease in the specificity of the test. From 1995 to 2007, the limit of troponin detection fell from 0.5 ng/mL to 0.006 ng/mL (see below graph). Robert Jesse summed up this frustration with the following quote:
When troponin was a lousy assay it was a great test, but now that it’s becoming a great assay, it’s getting to be a lousy test.
Recently, I have been asked by several students at my home institution (UTHSC at San Antonio) to help them understand bundle branch blocks. This is different than some of my usual posts because it is meant to be more educational than evidence based. So here we go. The normal conduction system of the healthy heart is shown to the right. If there is a delay or block in the left or right bundle, depolarization will take longer to occur. Therefore we get a widened QRS (>0.12 sec or >3 small boxes).
There are several algorithms that are currently used to help distinguish Supraventricular Tachycardia (SVT) with aberrancy and Ventricular Tachycardia (VT). Many of these algorithms lack specificity, and let’s face it, who can remember if the absence of an RS complex in the precordial leads is VT or SVT with aberrancy. So what if there was a criterion that had a good sensitivity (SN), specificity (SP), and was one simple step?
Due to the overwhelming popularity of Dr. Salim Rezaie‘s recent post discussing the Brugada criteria for SVT with aberrancy vs VT, Dr. Jason West (@JWestEM, an EM resident from Jacobi/Montefiore) kindly helped to co-author and package this information into a PV card for quick reference. To use this sequential, four-question approach, if at any time you answer YES to the question, it is ventricular tachycardia.
All the years of ultrasound training in residency has paid off. You found the large pericardial effusion in the hypotensive patient who is still alive, but looks sick. You are a star! The only problem was that you never performed a pericardiocentesis in an awake patient. The cardiology fellow is at home sleeping and/or the closest receiving hospital is about 1 hour away. Now what?
Dr. Arun Nagdev reviews how to do an ultrasound guided pericardiocentesis as part of this new, ongoing series of advanced ultrasound tips for emergency physicians.