Pendell (Pendell Meyers, of course), with a little help from Smith, coined a new LAD Occlusion pattern "Precordial Swirl," in which there is rightward STE vector, with STE in V1 and aVR, with reciprocal STD in V5 and V6. It is due to transmural ischemia not only of the anterior wall and apex, but due to transmural ischemia of the septum, usually due to occlusion proximal to the first septal perforator.
Here is the visual explanation for the term we have coined, as this LAD occlusion pattern causes upward STT shifts in V1-2 and downward STT shifts in V5-V6:
It is easy to mistake if for LVH (or vice versa) because LVH often shows STE in V1-V3 and STD in V5, 6. LBBB also has discordant STE in V1-V3 and STD in V5, 6 -- I will not be giving examples of this, as they are readily available all over the blog.
As always, LAD OMI need not meet STEMI criteria and usually does NOT!
Remember: when there is ST Elevation in V2-V4, and you are wondering whether this could be NORMAL ST Elevation, it is NEVER normal if there is any ST Depression in any precordial lead, or any limb lead other than aVL. This is why ST Depression is one of the Exclusions to using the LAD Occlusion/Normal Variant Formula.
Here are many examples which we have already posted:
5 of LVH mimicking Precordial Swirl
1 case (Case 6) of LVH mimicking precordial swirl, but it is actually LVH + posterior OMI
14 Cases (Cases 7-20) of OMI with Precordial Swirl
First, 5 mimics:
Case 1. A 50-something with cocaine chest pain and ST Elevation in V1 - V3
Case 2. A 60-something with Syncope, LVH, and convex ST Elevation
Case 7. Septal STEMI with ST elevation in V1 and V4R, and reciprocal ST depression in V5, V6
Case 9. A man in his 50s with "gas pain"
- I like to focus on the ST-T wave appearance in leads V1 and V6.
- Although 1-2 mm of upsloping ST elevation is commonly (and normally) seen in anterior leads V2 and V3 — most of the time we do not see ST elevation in lead V1 (or if we do — it is minimal!). Therefore — I become immediately suspicious of "precordial swirl" whenever there is suggestion of LAD OMI and in addition lead V1 looks different than expected!
- NOTE: Sometimes recognition that lead V1 looks "different-than-expected" — is only forthcoming after realizing that lead V2 is clearly abnormal.
- Although admittedly subtle — the ST segment coving with slight but disproportionate ST elevation in lead V1 of A, B and C in Figure-1 is clearly an abnormal appearance for the ST segment in lead V1. In association with neighboring chest leads suggestive of acute LAD OMI — this picture should raise suspicion of "precordial swirl".
- Example F in Figure-1 is more subtle — because the S wave in lead V1 is deeper. That said — this coved shape of ST elevation in lead V1 of F should still raise suspicion in a patient with new symptoms.
- The ST-T wave segment in lead V1 of example D — closely resembles the "shape" of LV strain in an anterior lead from a patient with LVH. However, the S wave is not at all deep in either lead V1 or V2 — which in a patient with chest pain should strongly suggest the possibility of "precordial swirl".
- The ST-T wave shape in lead V1 of example E is also subtle. However, the T wave in neighboring lead V2 looks overly peaked — which in a patient with new symptoms should raise suspicion of a disproportionately positive T wave in lead V1.
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| Figure-1: Selected sets of V1,V2 leads from the examples of "precordial swirl" provided above by Dr. Smith (See text). |
- Perhaps the best way to become comfortable with the concept of "proportionality" (regarding relative size of ST-T wave deviations compared to QRS amplitude in the respective lead) — is by seeing a series of examples, such as the cases of LVH that mimic precordial swirl in Dr. Smith's discussion above.
- I further explore this concept in detail in My Comment — at the bottom of the page in the February 6, 2020 post in Dr. Smith's ECG Blog.
- Once I've decided that the tracing I am looking at is not LVH that mimics precordial swirl — I focus on the shape of the ST-T wave in lead V6.
- I've reviewed my approach to the ECG diagnosis of LVH on many occasions in Dr. Smith's Blog (See especially My Comment at the bottom of the page in the June 20, 2020 post). I've reproduced from this June 20, 2020 post in Figure-2 schematic illustration of the ST-T wave appearance in one or more lateral leads demonstrating LV "strain".
- Other signs suggestive of acute LAD OMI.
- The ST-T wave in lead V1 looking "different-than-expected".
- A relatively flattened appearance to the depressed ST segment in at least lead V6 (if not also in lead V5).
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| Figure-2: Illustration and description of LV "strain" (excerpted from My Comment in the June 20, 2020 post in Dr. Smith's ECG Blog). |
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