Differentials of "Shark-fin" sign on ECG beyond myocardial infarction, an EHJ case report.

Triangular ST-segment elevation or 'shark-fin' sign has been described as a specific indicator of acute coronary occlusion and large myocardial ischaemia, translating into poorer prognosis. Authors Verdoia et al in a case report published in European Heart Journal, have described this sign in a case of Tako-tsubo cardiomyopathy (TTC) and hypothesize its appearance to the presence of more severe physical stressors and neurological involvement in their patient.

A 51-year-old woman presenting with incoming epileptic attacks and concomitant pyometra. Despite controlling epilepsy with phenytoin and the surgical treatment of the infection, she developed sepsis requiring vasopressors, and thereafter sustained ventricular tachycardia and diffuse ST-segment elevation with the 'shark-fin' sign (Figure)

Her medical history included hypertension in therapy with ramipril 5 mg daily, diabetes mellitus treated with fast and long-acting insulin, personality disorder in therapy with flufenazide in depot formulation and alcohol abuse. Phenytoin was started for focal seizures.

The echocardiogram showed a severe reduction of left ventricular function (EF around 30%) with akinesia of the apex and periapical segments, suggestive for apical ballooning. The echocardiogram showed a severe reduction of left ventricular function (EF around 30%) with akinesia of the apex and periapical segments, suggestive for apical ballooning. Coronary angiogram was done considering the possibility of acute coronary syndrome but no significant lesion was found.

Thus, phenytoin was substituted with levetiracetam, without epileptic relapse, and vasopressors were progressively stopped. The ECG changes subsided spontaneously over next few days and patient recovered from septic shock with antibiotic and inotropic therapy could be tapered and finally stopped.

Her echocardiogram at discharge, after 25 days from the acute event, showed the complete recovery of the left ventricular function (EF 60%) with normal kinesis and no valvular dysfunction. Therapy with aspirin, ramipril, and beta-blockers was maintained at discharge.

ST-segment elevation has been described in about 56% of TTC cases, although its amplitude is usually lower than in anterior ST-elevation myocardial infarction. Vasospasm, local intermittent microvascular constriction and catecholamine-induced increase of myocardial metabolic demand can certainly be claimed for the observation of a diffuse ischemic pattern in these patients.

In a large study, enrolling 158 consecutive subjects with TTC, Tarantino et al (1) described the lambda-wave pattern in five patients and in all of them physical stressors were more commonly associated to the 'shark-fin' sign than to psychological causes.

Similarly, in a US cohort study (2), TTC was associated with several acute neurological diseases, the most common being subarachnoid haemorrhage, status epilepticus, and seizures.

A similar brain–heart interaction leading to TTC and 'shark-fin' sign presentation can be hypothesized in this patient, in consequence of the relapsing epileptic attacks, although the cardiac insult occurred several days after the main convulsive episode. Indeed, despite phenytoin infusion prevented the epileptic manifestations, an alteration of the neurological autonomic regulation cannot be excluded.

Furthermore, sepsis, high-dose catecholamines and phenytoin cardiac toxicity could have played a role in the pathogenesis of a 'multifactorial' TTC, further contributing to the rarity of the case.

"The concomitant summation of multiple stressors in a single patient and the electrocardiographic presentation with the 'shark-fin' sign represent rare conditions, which are associated with a poor prognosis", concluded the authors.

Source: EHJ case reports: Monica Verdoia, Orazio Viola, Federica Marrara, Pier Luigi Soldà, A 'shark'-masked electrocardiogram: case report of a Tako-Tsubo syndrome, European Heart Journal - Case Reports, Volume 5, Issue 5, May 2021, ytab132, https://doi.org/10.1093/ehjcr/ytab132

References:

1. Tarantino N, Santoro F, Guastafierro F, Di Martino LFM, Scarcia M, Ieva R et al. "Lambda-wave" ST-elevation is associated with severe prognosis in stress (takotsubo) cardiomyopathy. Ann Noninvasive Electrocardiol 2018;23:e12581.

2. Morris NA, Chatterjee A, Adejumo OL, Chen M, Merkler AE, Murthy SB et al. The risk of takotsubo cardiomyopathy in acute neurological disease. Neurocrit Care 2019;30:171–176.