Written by Pendell Meyers
A man in his 70s with no cardiac history presented with acute weakness, syncope, and fever. He denied chest pain or shortness of breath.
An ECG was performed in the ED at 1554:
 |
| Original image unavailable, this is the only recorded scanned ECG available. See below for PM Cardio digitized version of this. |
 |
| PM Cardio digitized version. What do you think? |
Sinus rhythm with mostly normal QRS complex. There is abnormal STE in V1-V3, and likely STD in V5-6. In the right context, it could be concerning for anterior/septal/RV OMI. But there is also morphology potentially consistent with Brugada pattern/phenocopy, especially in V2.
In the clinical context of weakness and fever, without chest pain or shortness of breath, the likelihood of Brugada pattern is obviously much higher.
However, missing an OMI would have terrible consequences.
Smith comment: if this were a chest pain patient, I would say that this is either septal OMI or isolated right ventricular OMI (RV OMI) until proven otherwise). But with these symptoms, OMI is not likely. In a patient with syncope and fever, this ECG looks more like Brugada.
The Queen of Hearts uses only the ECG (she doesn't know any clinical context), and here is her interpretation:
Smith comment: the Queen interprets ECGs as if the patient had chest pain. So maybe she is better than I am.
A prior ECG from 1 month ago was available:
 |
The presentation ECG was interpreted as STEMI and the patient was transferred emergently to the nearest PCI center.
Smith comment: the ECG in question could be due to Brugada, even though there is a change from baseline. We know that fever can often unmask Brugada.
A repeat ECG was performed before the cath at 1610:
 |
See digitized version below. |
 |
| PM Cardio digitized version. |
QOH Interpretation:
The initial troponin I (older generation) at the first ED was barely positive at 0.06 ng/mL.
The patient proceeded to cath where all coronaries were described as normal with no evidence of any CAD, spasm, or any other abnormality.
Another troponin was drawn around the time of cath, troponin T (older generation), which was normal at less than 0.01 ng/mL.
Formal echocardiogram showed normal EF, no wall motion abnormalities, no pericardial effusion.
No more troponins were done.
He was found to be influenza positive.
1849 after cath:
 |
| Brugada pattern is gone! (presumably the fever is gone too) |
Next morning:
 |
| Brugada pattern is back in V2, but less severe than initial ECGs. Is there fever again? |
There were no dysrhythmias on cardiac monitor during observation.
Syncope and weakness were attributed to acute illness from influenza.
The patient did well and was ultimately discharged home.
See more cases of Brugada due to fever here.
This discussion comes from this previous post:
Hyperthermia and ST Elevation
Discussion
Brugada Type 1 ECG changes are associated with sudden cardiac death (SCD) and the occurrence of ventricular dysrhythmias. Patients that develop a Type 1 pattern without any precipitating or provoking factors have a risk of SCD of 0.5-0.8% per year. In patients that only have this pattern induced by a sodium channel blocking agent have a lower rate of SCD (0 - 0.35% per year)[1]. Drugs that have been associated with Brugada ECG patterns include tricyclic antidepressants, anesthetics, cocaine, methadone, antihistamines, electrolyte derangements, and even tramadol. [2].
===================================
MY Comment, by KEN GRAUER, MD (7/22/2023):
===================================
The importance of today's case is evident from the course of events that transpired — namely, that awareness of the entity of Brugada Phenocopy (and comfort in recognizing this pattern) — can avoid misdiagnosis that all-too-often leads to unnecessary cardiac catheterization.
- The reason we continue to periodically review cases of Brugada Phenocopy — is that this entity is still overlooked, as it was in today's case (See My Comment at the bottom of the page in the May 5, 2022 post — and in the November 25, 2022 post of Dr. Smith's ECG Blog — among other cases of Brugada Phenocopy).
No matter how many times I have seen Brugada-1 and Brugada-2 ECG patterns — I still find myself referring back to the images in Figure-1:
-USE.png) |
| Figure-1: Review of ECG Patterns in Brugada Syndrome (adapted from Brugada et al in JACC: Vol. 72; Issue 9; 2018) — A) Brugada-1 ECG pattern, showing coved ST-segment elevation ≥2 mm in ≥1 right precordial lead, followed by a negative T-wave. — B) Brugada-2 ECG pattern (the “Saddle-back” pattern) — showing concave-up ST-segment elevation ≥0.5 mm (generally ≥2 mm) in ≥1 right precordial lead, followed by a positive T-wave. — C) Additional criteria for diagnosis of a Brugada-2 ECG pattern (TOP: the ß-angle; BOTTOM: A Brugada-2 pattern is present if 5 mm down from the maximum r’ rise point — the base of the triangle formed is ≥4). |
- A Brugada Type-1 ECG pattern is diagnosed by the finding of ST elevation of ≥2 mm in one or more of the right precordial leads (ie, V1, V2, V3) — followed by an r’ wave and a coved or straight ST segment — in which the ST segment crosses the isoelectric line and ends in a negative T wave (See Panel A in Figure-1).
- A Brugada-1 pattern may either be observed spontaneously (with leads V1 and/or V2 positioned normally — or positioned 1 or 2 interspaces higher than usual) — or — a Brugada-1 pattern may be observed on provocative drug testing after IV administration of a sodium-channel blocking agent such as ajmaline, flecainide or procainamide.
- NOTE #1: Although Panel A in Figure-1 illustrates the typical appearance of a Brugada-1 ECG pattern — there are variations on this "theme". The common denominator for Brugada-1 ECG patterns is ST elevation that shouldn't be there in ≥1 right precordial leads — followed by a rapid ST segment downslope into a negative T wave. The elevated ST segment often manifests a sharp descent — but at times, it may have a more rounded appearance.
- NOTE #2: In years past, the diagnosis of Brugada Syndrome required not only the presence of a Brugada-1 ECG pattern — but also a history of sudden death, sustained VT, non-vasovagal syncope or a positive family history of sudden death at an early age. This definition was changed following an expert consensus panel in 2013 — so that all that is currently needed to diagnose Brugada Syndrome is a spontaneous or induced Brugada-1 ECG pattern, without need for additional criteria.
- Panel B in Figure-1 illustrates the Brugada Type-2 or “Saddle-back” ECG pattern. This pattern may be suggestive — but is not diagnostic of Brugada Syndrome. Depending on the presence or absence of other clinical factors — a Brugada-2 ECG pattern by itself (ie, without a Brugada-1 pattern) — may not be clinically significant.
- KEY Point: A number of conditions other than Brugada Syndrome may temporarily produce a Brugada-1 ECG pattern (World J Cardiol 6(3):81-86, 2014). These include (among others) — acute febrile illness — variations in autonomic tone (as may occur with syncope) — hypothermia — ischemia or infarction — cardiac arrest — and electrolyte disorders (especially hyperkalemia — but also hypokalemia/hyponatremia). Patients with such conditions that may transiently mimic the ECG findings of a Brugada-1 pattern are said to have Brugada Phenocopy.
- The importance of being aware of this phenomenon of Brugada Phenocopy — is that correction of the underlying condition may result in resolution of the Brugada-1 ECG pattern (with a far better prognosis compared to patients with true Brugada Syndrome).
- IF it is clinically clear that the transient appearance of a Brugada-1 ECG pattern was "pure" Phenocopy (and solely due to an acute illness or condition that was easily corrected) — then no additional evaluation may be needed. If instead — the patient has other risk factors, a positive family history, or other clinical concerns — then referral for provocative testing with a sodium channel blocking agent can be undertaken to rule out Brugada Syndrome.
- As per Dr. Meyers — the clinical setting in today's case is KEY. Today's patient presented with acute weakness, syncope and fever, but no chest pain or shortness of breath. As a result — we should immediately recognize a number of factors that may predispose to Brugada Phenocopy in this patient with no acute cardiac symptoms.
- As per Dr. Meyers — the initial ECG in today's case is clearly abnormal, with ST elevation in leads V1-thru-V3 and a hint of ST depression in leads V5,V6 (See ECG #1 — that I've reproduced in Figure-1). IF this patient had new cardiac-sounding chest pain — I would have no hesitation about promptly activating the cath lab.
- That said — In the absence of chest pain, and in the presence of several symptoms that may predispose to Brugada Phenocopy (ie, syncope — fever — and weakness that might be related to an electrolyte disorder) — I thought the "picture" of the ST elevation in ECG #1 that was rounded, with steep descent into terminally negative T waves, and equally present in V1,V2,V3 but absent in other chest leads — was more likely to represent a Brugada-1 pattern from Phenocopy, rather than acute infarction.
- The previous ECG was misinterpreted. While true that anterior ST elevation was not present on the ECG recorded 1 month earlier — this does not necessarily mean that new ST elevation on today's initial ECG is indicative of acute anteroseptal infarction. On the contrary — I thought the previous ECG supported my impression of Brugada Phenocopy because: i) The other 9 leads in ECG #2 look virtually identical to leads I,II,III; aVR,L,F; and V4,5,6 in ECG #1 (including the hint of ST depression in lead V6); and, ii) While not elevated — the shape of the ST segment in lead V1 of ECG #2 was already rounded in this previous tracing (ie, IF a Brugada Phenocopy were to superimpose itself on this patient's baseline tracing — it might look identical to the overall ECG "picture" that we see in ECG #1).
- BOTTOM Line: It can at times be extremely challenging to distinguish between anterior ST elevation from a benign Brugada Phenocopy pattern vs an acute anteroseptal STEMI. It is always prudent to be cautious! That said — in the absence of any acute cardiac symptoms — and in the presence of conditions predisposing to Brugada Phenocopy + an ECG pattern that looks like Brugada-1 in leads V1,2,3 — but without acute ST-T wave changes in other leads — Brugada Phenocopy becomes much more likely. There may therefore be no need to rush the patient to cardiac cath — especially if troponins come back normal — Echo at the bedside shows no localized wall motion abnormality — and especially IF as the patient's fever comes down — syncope resolves — and any electrolyte disorders are corrected — a repeat ECGs show reduced anterior ST elevation.
-USE.png) |
| Figure-1: Comparison between the initial ECG in today's case — and a prior ECG done ~1 month earlier. (To improve visualization — I've digitized the original ECG using PMcardio). |
No comments:
Post a Comment
DEAR READER: I have loved receiving your comments, but I am no longer able to moderate them. Since the vast majority are SPAM, I need to moderate them all. Therefore, comments will rarely be published any more. So Sorry.