Shark fin or triangular QRS-ST-T waveform ECG pattern, also known as lambda-wave ST elevation or giant R wave syndrome, is a particular ECG presentation where QRS complex, ST-segment and T-wave are fused in a unique complex. Originally described in some patients with ST-segment elevation myocardial infarction (STEMI) during the acute phase, it has been found to be associated with a high risk of ventricular fibrillation and cardiogenic shock as well as with a high in-hospital mortality. However, shark fin ECG pattern has also been reported in patients with non-acute coronary syndrome related ST-elevation (NASTEP), including stress-induced takotsubo syndrome (TTS). Fourteen such cases (all females) have been reported so far. The authors present a case of a 56-year-old male with shark fin ECG pattern associated with TTS triggered by burn injuries of head, back, upper, lower limbs and the respiratory tract. Due to respiratory insufficiency and heart failure with hemodynamic compromise, he required mechanical ventilation and catecholamines use. Echocardiography showed apical and midventricular akinesia with left ventricular ejection fraction and global longitudinal strain reduced to 30% and -6.8%, respectively and a high segmental post-systolic index. Shark fin pattern maintained within 2 days, then ST-T evolution was observed. Echocardiographic improvement followed by almost normalization were seen after 6 and 9 days, respectively. No cardiac arrhythmias were recorded as in most of the described cases with shark fin ECG and TTS.
Keywords: post-systolic shortening; giant R-wave syndrome; lambda-wave ST-elevation; longitudinal strain; shark fin ECG; takotsubo syndrome; triangular QRS-ST-T waveform pattern.