The Emergent Evaluation of WCTs Made Insanely Simple!

Our Rationale: Hemodynamic Status

When confronted with a patient with WCT, your number one priority is to keep the patient alive. How do we do that? By stabilizing their hemodynamic status and keeping it that way! Begin by sticking to the established guidelines of the ABCs (airway, breathing, and circulation) from basic and advanced life support. Then, follow the treatment guidelines provided by the clinical guidelines cited previously. When you are faced with an unstable patient, the treatment plans are simple: Treat the patient as if he or she is in VTach! Don’t waste time evaluating the micro-minutia; stick to basics.

Don’t forget that in order to maintain hemodynamic stability, the two leading factors to keep in mind are the rate of the rhythm and the reestablishment of synchronized contractions. In other words, you need to break or control the rhythm as quickly as possible using any means available to you, unless there are some contraindications to their use. These means include the use of cardioversion, defibrillation, and even overdrive pacing, if you are qualified to use them. Many clinicians fail to use these lifesaving procedures early while the patient still has adequate reserves, choosing instead to wait for the last possible moment at the expense of the patient, after all the reserves have been exhausted and the chances for a successful resuscitation are low.

Once the patient has been hemodynamically stabilized, we can then move on to the nonurgent phase. Note that nonurgent does not mean the patient is out of the woods. Remember that the hemodynamic instability can return as quickly as the next premature ventricular contraction can trigger another circus movement. In other words, the tachycardia can restart in seconds.

Typically, however, the nonurgent phase provides a window of stability, allowing us to turn our attention to obtaining a better, more inclusive history and physical and to completely evaluate the rhythm diagnostically. If you can arrive at a definitive diagnosis, you should then begin instituting more focused treatment immediately, if any is available. Once again, time is of the essence as we are trying to prevent any deterioration of the hemodynamic status or the resurgence of the tachycardia.

Our Rationale: VTach, VTach, VTach . . .

When I was a wee lad in grade school, I remember hearing the teacher mention something that has stuck with me all of these years. The topic of the conversation was related to test questions and, specifically, to whether multiple-choice or essay questions provided the better assessment of a student’s knowledge base. Needless to say, she was a believer in essay questions. Her main argument was that even a trained monkey could get 25% of the questions correct in a multiple-choice exam (in those days, we typically had one question and four answers to choose from). And she was right. Later, in college, we were told something similar when preparing for the national exams: If you don’t know the answer, choose C! Well, that was almost right (but close enough since we don’t want to bore you with 20 pages of statistics).

All of us were probably taught the same things and that little stroll down memory lane does serve a purpose. It is an established fact that when you are dealing with a WCT, you can never be 100% certain whether a rhythm is a VTach or an SVT-A. Considering that making the wrong therapeutic choices could kill your patient, that is hardly a comforting thought. Now, no one wants to be a trained monkey, let alone one that correctly hits only 25% of the time. There are a few scenarios, however, in which I wouldn’t mind hitting the correct answer 80% to 90% of the time! In this chapter and the next, we will cover quite a lot of criteria to help you make the best educated guess.

Moving on, as we have discussed, we can predict with 80% to 90% certainty that a WCT is VTach just from answering a few simple questions. That is, in our opinion, very impressive—especially considering that physician raters (including emergency physicians and cardiologists) in most arrhythmia recognition studies typically vary anywhere from about 40% to a little better than 90% at correctly distinguishing a VTach from an SVT-A, when using either simple or complicated criteria (raters analyze the rhythm strip and rate whether the diagnosis is correct). Note that these raters knew ahead of time that the rhythm was a WCT and had been previously educated on what to look for! Compared to 80% to 90%, those statistics are pretty dismal.

Many studies seem to agree that the lack of inter-rater reliability boils down to two factors: (1) Individual variations commonly are found between patients and their ECGs, creating discrepancies that cannot fit neatly within the criteria being applied, and (2) the more attention to detail and time spent evaluating the strip, the higher the reliability. So, how do you improve the number of correct diagnoses? You set up a system that does not need a microscopic evaluation of every individual variation (see the next section), and you get people to focus more (by helping them to remember the criteria better and make the evaluation nonpunitive).

In the “real world,” the statistics are even more dismal. Why? Because most clinicians do not remember the long strings of criteria used to differentiate VTach from SVT-A correctly, and, even more importantly, they cannot dedicate the adequate time needed to fully evaluate a strip or ECG when confronting a medical emergency. Facts like these help to validate the observations maintained by many practicing clinicians that statistics obtained in the lab are not the same as those found in “the real world.”

After all is said and done, the level of attention given and time spent evaluating the strip were actually the most important factors for preventing misdiagnoses. It just goes to show that the reliability of anything in medicine, except physically measurable objective findings, is subject to the proficiency of the clinician involved and the attention to detail they provide.

Developing a deeper understanding of the inner workings causing the arrhythmias and their complications, along with using mnemonics to assist with the retention of the material, are examples of how to increase the proficiency of the provider through education. Increasing focus comes naturally when, once again, the clinician knows the mechanisms and pathophysiology that create and maintain arrhythmias and feels that participation in problem solving will not lead to real or perceived punishment (malpractice, ridicule, and loss of one’s license to practice, for example). When you start at 80% correct in any test, acing it becomes much easier.

So, how do we overcome the obstacles that we face in the emergent phase of treatment? By remembering that the best we can hope for is to shoot for the highest probabilities that we can get in the shortest time span possible. In other words, since the emergent phase is short, we need to increase our odds as quickly as possible.