Sunday, April 25, 2021

A woman in her 40s with palpitations and chest pressure of unusual etiology

Submitted and written by Magnus Nossen MD from Norway, with some minor edits by Meyers and Smith


A female in her 40s with no known cardiac disease presented to the ED with palpitations and presyncopal episodes recurring over several years, usually lasting 1-5 minutes, sometimes associated with chest discomfort, and increasing in frequency over the past few months. 

Previously she had an echo and 5 days ambulatory ECG performed at a private clinic, both normal. The suspected arrhythmia had evaded capture. She then purchased a smart watch with the possibility for ECG recording. She presented to the emergency room with print outs recorded during palpitations. She was asymptomatic at presentation.


ECG#1:


ECG#1: Print out of rhythm strip from her apple watch (25mm/s). As far as one can interpret a single lead, this shows an irregular broad ventricular tachycardia with axis alternation. Duration of this episode was 90 seconds total. From this single rhythm strip differential diagnoses include atrial fibrillation with aberrant conduction/preexcitation, or polymorphic VT (which can be due to long QT, ischemic, or catecholaminergic in variety). Based on the normal beats at the end of the rhythm strip, there is no evidence of long QT. The history was not consistent with that of CPVT. She had not experienced episodes of palpitation/presyncope during physical activity. She was admitted for further work up. 



ECG#2:



ECG#2: At rest upon admission: SR, normal interval and axes. Normal repolarization. No sign of preexcitation visible. Normal QTc. (434ms) No Brugada morphology. No epsilon waves. Slight QRS notching inferior leads, but not really consistent with crochetage sign. Interpretation: Normal resting ECG.



Echocardiography revealed a structurally normal heart with normal function. MRI showed a completely normal right and left ventricle with normal systolic function and EF 70%. Stress test was performed adequately without arrhythmia or ischemic findings. The patient was sent for coronary angiogram. This showed patent LMCA, LAD, Cx and RCA. No atherosclerotic changes. Gene test for catecholaminergic polymorphic VT was negative. An ICD was placed. Patient was started on beta blocker discharged home with home monitoring of the ICD. 


After ICD placement and beta-blocker treatment she experienced increasing frequency of paroxysms of palpitations and presyncope. She was admitted again for telemetry and observation. She had several episodes (lasting up to 2 minutes) of palpitation/presyncope before admission and while on telemetry. There was time to record 12 lead ECGs during these episodes. 



ICD Report:


ICD Report: This is from the ICD-report which shows both the atrial channel (top waveform) and the ventricular channel (bottom waveform). The ventricular channel shows irregular ventricular tachycardia with quite a few R-R intervals less than 200ms translating to ventricular rates greater than 300/minute for short duration. There were 14 episodes of VT during one 24 hour period with ventricular rates between 200-283/min. Most episodes were only of a few seconds duration.



ECG#3: 



ECG # 3: This 12-lead is recorded during one of her episodes. This ECG shows runs of irregular ventricular tachycardia. Slightly varying QRS-morphology resembling RBBB+LAFB. Intermittent cessation with normal sinus rhythm. 



ECG#4:




ECG# 4 (limb leads on the left, and precordial leads on the right). This ECG is highly interesting and recorded during another of the patient's episodes. This ECG shows very frequent PVCs with some normally conducted complexes.


However there are striking findings regarding the etiology of the condition! There are several narrow complexes visualized both in the standard leads and in the precordial leads which show “shark-fin” ST-elevation in leads II, III, aVF and V5-V6 with reciprocal ST-segment depression in early precordial leads and lateral leads. The wide complexes show excessively discordant ST segment elevation in II, III aVF and excessively discordant ST-depression in lead I and V1-V2. There is inappropriately concordant ST segment depression in lead I.  As per Smith’s modified Sgarbossa criteria one can sometimes diagnose transmural ischemia from the aberrantly conducted complexes alone –  the narrow complexes of course further support the etiology of intermittent transmural ischemia as the cause of malignant arrhythmia! 



ECG#5 and #5-1:



ECG#5 and ECG#5-1: From the same episode of tachycardia. Similar to ECG number 4, but more tachycardic. 178/minute. My interpretation is that the mechanism of ventricular tachycardia is not re-entry but rather severely ischemic myocardium leading to myocardial irritability triggering PVC w/ foci located in the region of the posterior fascicle of the left bundle branch. 




ECG#6:




ECG# 6 This is a rhythm strip from telemetry. The patient had several episodes of tachycardia – as one can observe, there is clear dynamic ST-T pathologic changes with ST-elevation prior to the short episode of polymorphic VT. This again further support the diagnosis and that the observed ST-T changes seen during tachycardia are not type II mediated, even though this was never really suspected as a cause. 



ECG#7:




ECG#7: In this ECG one managed to capture initiation of ventricular dysrhythmia. There is some baseline wander – however the ST-elevation is unmistakable, and after being present for some time the ischemia seems to trigger PVCs. 



She was sent for provocation test. Beta blocker discontinued. She was not started on treatment prior as that could mask spasm. 




Angiogram images and videos:


Before provocation

During provocation






Angiography images and videos of the spasm are included above. The provocation test was performed on the LAD. Because the STE distribution in the ECG was RCA domain, they did not do provocation in RCA due to risk of inducing malignant arrhythmia. The spasm test was considered positive (chest pain and ECG changes).


Long acting nitrates and diltiazem initiated. She was discharged home. Home monitoring of ICD has not revealed any significant arrhythmia. Interrogation of ICD after 8 weeks showed no significant arrhythmia. Symptoms of presyncope have disappeared with treatment.


The etiology to the arrhythmia was in this case elusive. The patient had several ECGs recorded during tachycardia. Some with and some without disproportionate ST-segment shift. This case illustrates nicely that knowledge of the Smith modified Sgarbossa criteria is very useful in the clinical setting, here raising strong suspicion of ischemia due to spasm as the cause of arrhythmia. The patient appears to have been given the correct treatment with clinical response.


Learning Points:

Ischemia is one of the most important etiologies of polymorphic VT.

Coronary spasm can be an elusive, transient, and confusing cause of intermittent ischemia and dysrhythmias.

The principles of appropriate discordance (including the modified Sgarbossa criteria) can be applied to almost any wide complex QRS, including even PVCs.


See Dr. Nossen's other(!) case of fascinating coronary spasm here:

Fascinating case of dynamic shark fin morphology - what is going on?


See these cases for using the modified Sgarbossa criteria in the context of PVCs:

Look at the PVCs!!


Look at the PVCs (again)!!


Hyperacute T-waves and Concordant ST Elevation seen in PVCs only


Anterior STEMI and multiform PVCs with Narrow Coupling Interval. When to give beta blockers in acute MI?




5 comments:

  1. Fascinating! Congratulations for the management of this difficult problem
    As a "noncardiologist" this case leaves me a a little bit confused (but certainly on a higher level) and depressed, because my first guess with the print out of the apple watch was atrial fibrillation with preexcitation. In my country we would call this tachycardia FBI (sorry) which stands for fast, broad and irregular. And we we are told in such a case there should be a high supsicion of AF plus preexcitation.
    I would be very grateful if you can give me some clues for the differential of these conditions, because the therapeutic strategies would be very different.
    How often does ischemia provoke irregular instead of regular WCT.
    I have to additional questions regarding the management of this case
    1. do you think it was possible to postpone (or even avoid) the ICD implantation, because this is a very invasive procedure and it is not trivial to remove it, if you dont need it any more (Would a live vest in your opinion an option)
    2. do you think that stenting of a spastic semgnent can be an option in certain cases?
    Thank you again for this insightful case; I learned a lot
    Christian

    ReplyDelete
  2. I’m confused. This is a very interesting case but the commentary states that in ECG #4 the complex in the red boxes is a PVC and that this ECG therefore demonstrates the usefulness of Smith’s modification of the Sgarbossa criteria to diagnose transmural ischaemia when the QRS is broad. However, the complex in the red boxes is not broad – it is a normally conducted complex of pretty much the same axis and chest lead R-wave progression seen in the ECGs that show clear sinus rhythm and therefore simply demonstrates the conventional signs of transmural ischaemia. If anything demonstrates the application of the modified criteria it is the rest of the ECG, ie all the complexes that are not in the red boxes, and in fact the textual description of excessively discordant ST elevation in II, III and aVF as well as in V1 and V2 only applies to the complexes that are not in the red boxes.

    ReplyDelete
    Replies
    1. Dave, you are correct. We have fixed it. Thanks!

      Delete
  3. truly incredible and more than a little frightening. how many of these patients have i sent home, i wonder.

    thank you Steve, Pendell, and Magnus.

    ReplyDelete
  4. Now this was a lovely read.
    This was a cardiac version of an episode of Elmer Fudd and Bugs having a run at it. Well presented.

    Thank you for this.

    Alexander
    EM
    South Africa

    ReplyDelete

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