Tom B.

Do you have the strips by any chance? It's so rare to see true electical capture achieved in the field I'm sure we'd all learn a lot from the case. In my experience the ED physician wants to see the underlying rhythm anyway. I remember on one occasion the pacer was turned off and there was (almost) nothing underneath. They turned it right back on and took the patient up to the cath lab with our LP12 attached. Not sure what happened when they got there but one of the nurses brought back our machine.

Lots of things "seem reasonable" but turn out to be harmful. Consider this video from the father of evidence based medicine. Fast-forward to 5:00.

The AHA develops guidelines based on the evidence but it also produces educational materials. Many top performing EMS systems have eliminated the requirement of maintaining an ACLS certification because the video-driven ACLS course is so awful. We could talk all day about how the "onus is squarely on our shoulders" but the reality is that ACLS is a required certification for the vast majority of paramedics in the country but it no longer serves our needs. Perhaps you think that every EMS system should invent its own wheel but I'd rather see a thoughtful ACLS course be created by the AHA for EMS professionals. It's an opinion I've voiced to the Public Safety Team of the AHA and they seem interested in correcting this problem. I hope they do.

ACLS does encompass the critically ill periarrest patient. Why do you think it does not? The ACLS Reference Textbook and Experienced Providers Manual is a fantastic resource. The dumbed down video-driven basic ACLS course is an abortion and we should require more of our paramedics than to be resuscitation technicians who can follow a cookbook but are incapable of considering the Hs and Ts. The AHA has FAILED when it comes to prehospital emergency medicine. Period.

Specifically AF/WPW where adenosine (along with CCBs) can induce VF. When you give adenosine it's a good idea to place the combo-pads first.

Rs complex in lead I with a tight R-wave so definitely not a LBBB.

I wrote a tutorial on axis determination here: http://ems12lead.com/2008/10/04/axis-determination-part-i/ Good luck! Tom

3rd degree AV block with junctional escape rhythm. Nonspecific ST-T abnormality. Notched J-point in several leads. Correlate with history and clinical presentation. Tom

If the patient has no history of heart disease, and there are RS complexes in the precordial leads, and the start of the R-wave to the nadir of the S-wave is less than 100 ms, and AV dissociation is absent, and there are no fusion or capture complexes, and Wellens' criteria are not positive for VT in leads V1 and V6, then yes, VT is less likely, but cannot be safely excluded, especially when taking into account the problem of inter-observer agreement.

"I did not believe I was looking at VT as the axis is leftward (VT should be extreme rightward), there is no precordial concordance (as seen in VT), the morphology looks asymmetrical and abbarant (not VT), the rate is awful high for VT, and the patient was somewhat young." This was a great case, but I'm going to clarify one point because it's very important. Ventricular tachycardia can have a frontal plane axis in any quadrant. A right superior axis helps support the diagnosis but absence of that finding does not exclude the diagnosis. Same thing with precordial concordance. There is no safe way to exclude VT based on QRS morphology. On rare occasions you might see ventricular flutter with a rate around 250 but you should suspect an accessory pathway whenever the rate approaches (or exceeds) 250. When it's a regular, monomorphic wide complex tachycardia, in theory it's okay to try adenosine, and in fact it may convert orthodromic or antidromic AVRT (or be diagnositc when the underlying rhythm is atrial flutter). Just remember to hit the PRINT button so you can see what happens during the asystolic pause. The drug of choice for this patient would be procainamide but in these types of situations "edison before medicine" is probably the wisest course of action for the hemodynamically unstable patient. Thanks for sharing the case, fiznat!

It means that 1:1 atrial flutter is a strong possibility. It also means that the patient may have an accessory pathway.

Cool ECGs, fiznat! Since the village elders are keeping their opinions to themselves I'll simply offer a couple of clues. The 2010 AHA ECC Guidelines say "go right ahead" with adenosine for a patient like this but I wouldn't be comfortable doing it even though it could prove to be diagnostic in this case. There's only one antiarrhythmic I'd consider and few EMS systems carry it because it's expensive and difficult to administer correctly (dosing and end points). "Wide and fast" is VT until proven otherwise in my book right up until the rate pushes (or exceeds) 250. Then I'm forced to consider another possibility because that's a bit fast even for VT (although it could be so-called ventricular flutter). Electrical cardioversion for unstable patients allows caregivers to avoid the potentially deleterious consequences of selecting the wrong antiarrhythmic which in some cases can be fatal. For stable patients I'm a big fan of "supportive care and transport". Tom

In the first place I made a typo. I wrote: "44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) greater than the terminal voltage (in the last 40 ms of the QRS complex)" It should have read: "44 had an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) less than the terminal voltage (in the last 40 ms of the QRS complex)" Or as the paper itself describes it: "[E]stimation of initial (vi) and terminal (vt) ventricular activation velocity ratio (vi/vt) by measuring the voltage change on the ECG tracing during the initial 40 ms (vi) and the terminal 40 ms (vt) of the same bi- or multiphasic QRS complex. A vi/vt >1 was suggestive of SVT and a vi/vt ≤1 of VT." As for "selecting the correct QRS" call up the full text of the article. Here is one small excerpt: "The vi and vt were measured in an individual QRS complex in any lead having a bi- or multiphasic QRS complex, in which the onset and end of the QRS were clearly visible and the initial ventricular activation was the most rapid (fastest). When either the initial or terminal 40 ms of the QRS complex displayed both positive and negative deflections, the sum of their absolute values (disregarding polarity) were used as the values of vi and vt. Because three channels were recorded simultaneously on the ECG tracings, the onset and end of the QRS were defined by the earliest and latest ventricular depolarization, respectively, among the three simultaneously recorded leads that included the lead with the fastest initial ventricular activation. Most frequently (in 87% of WCTs), the vi was the fastest in the precordial leads and the leads most commonly used for analysis of vi/vt were v3, v5, and v2 in decreasing order of frequency." Also see the caption in Figure 1. Does this really seem simple to you? I mean, I think I get it, but I'm a serious ECG dork. Tom

Job13_5 - Thanks for chiming in. From an academic perspective there are things I like about this algorithm, but there are problems with it also. In the first place, can we honestly say it's simplified? Consider Fig. 7. Out of 453 wide complex tachycardias: 35 showed AV dissociation > presumed to be VT 127 showed an initial R-wave in lead aVR > presumed to be VT 156 showed atypical BBB or bifascicular morphology > presumed to be VT (Note: Requires the clinician to understand typical vs. atypical patterns.) Now we're down to 135 of the original 453. 44 have an initial voltage (in the first 40 ms of a bi- or multi-phasic QRS complex) greater than the terminal voltage (in the last 40 ms of the QRS complex) > presumed to be VT (Note: I am simplifying this criterion because the stipulations for selecting the right QRS complex are bewildering). Do you think this criterion will be correctly applied by anyone other than EPs? I don't. Even if by some miracle this final criterion is correctly applied in the field (and no other mistakes are made) 15 of the remaining 91 patients (16%) were misidentified as having SVT with aberrancy when in fact they were experiencing VT. Do you like those odds? 76 of the original 453 patients (17%) were correctly identified (by exclusion) as having SVT with aberrancy. So again, the burden of proof is entirely on the person who says a wide complex tachycardia is something other than VT. The most important criterion of all is "wide and fast" but sadly, that's the criterion more and more paramedics are willing to ignore. The default diagnosis for a wide complex tachycardia should always be VT. I have no quarrel with the idea that we should "treat the patient, not the monitor" but if that's your position then why do you feel the need to make the pronouncement that it isn't VT? Call it a wide complex tachycardia that is well tolerated by the patient and transport the patient to the nearest hospital. That's a lot better than killing the patient with a calcium channel blocker. Tom

The problem is that mistakes are made (as high as 50% of the time) and there is poor inter-observer agreement (certainly the case every single time one of these threads hits the EMS bulletin boards). The most common error is misclassifying VT as SVT with aberrancy (as in this case) which has been proven to lead to clinical misadventure, including death. The algorithms have limited applicability for patients with preexisting intraventricular conduction defect (atypical right or left bundle branch block) and patients with an accessory pathway (antidromic AVRT). For a complete discussion about this see the ACLS Reference Textbook and Experienced Provider Manual (2003). Chapter 16: Stable Wide Complex Tachycardias. Some excerpts can be found here. I say the danger is greater in the prehospital setting because it's debatable as to whether or not antiarrhythmics are good or necessary in the prehospital setting in the first place. If the patient is hemodynamically unstable they should be cardioverted. If the patient is hemodynamically stable then there is time for expert consultation. Anitarrhythmic medications are dangerous and we should be handling them with the utmost respect. Tom