Sailing in the complexity of the ‘shark-fin’ sign

CLINICAL INTRODUCTION A woman in her 70s with no previous cardiovascular disease nor recent physical/emotional stress was admitted for transient anterolateral ST segment elevation myocardial infarction (MI). Urgent coronary angiography revealed an intermediate stenosis of proximal left anterior descending (LAD) artery and optical coherence tomography showed a plaque of multilayer appearance with no sign of plaque rupture, erosion or thrombus (figure 1A, online supplemental video 1). Left ventriculography revealed a typical apical ballooning (figure 1B, online supplemental video 2). The decision was taken not to treat this intermediate LAD stenosis. T2 mapping cardiac magnetic resonance (CMR) showed higher relaxation times in the anterior wall and in the apex (figure 1C) with no necrosis or scar (figure 1D). The following day, the patient experienced recurrent chest pain and ventricular fibrillation requiring electrical shocks. At that time, an electrocardiogram (EKG) revealed a transient appearance of the ‘sharkfin’ sign (figure 1E). Urgent coronary angiography showed an unchanged angiographic pattern. We therefore performed quantitative flow ratio (QFR, Medis Suite V.4.0) with QFR values dropping from 0.75 (first angiogram, figure 1F) to 0.49 (second angiogram, figure 1G).