410 “SHARK-FIN“ ECG: NOT ALWAYS A STEMI!

Abstract

Abstract Background Coronary malperfusion due to type A aortic dissection is a life-threatening condition where timely recognition and treatment are mandatory. The International Registry of Acute Aortic Dissection (AAD) shows that only 5% of AAD patients present with ECG evidence of acute myocardial infarction, and prognosis is ominous due to the additional myocardial damage and missed or delayed diagnosis. The shark fin waveform is an uncommon but high-risk ECG pattern formed by fusion of QRS, ST-segment, and T waves. It is associated especially with the sub-occlusion of the left main coronary artery or proximal left anterior descending artery with a high risk of death due to cardiac arrest and cardiogenic shock. Case presentation A 61-year-old man was admitted to our cardiac cath-lab for typical chest pain and suspected acute ST segment elevation myocardial infarction (STEMI). A triangular pattern known as the ‘shark-fin’ sign in the precordial and inferior leads, and mirroring ST-segment depression in dI and aVL was detected. Unexpectedly coronary angiography revealed normal epicardial vessels, but a very-regular-shaped staining of the aortic sinus was observed. This finding was suspicious for acute aortic dissection. Bedside 2D-echocardiography within the cath-lab demonstrated an intimal flap in the aortic root and arch, with mild aortic regurgitation. Contrast-enhanced computerized tomography (CT) confirmed our diagnosis of Type A aortic dissection (AAD) highlighting the same dissection flap revealed by angiography arising from the left coronary cusp of the aortic root. The left main trunk was not directly involved, but the dissection extended from the ascending to the distal aorta involving both left and right external and internal iliac arteries with a thrombotic occlusion of the right femoral-iliac axis There was also a right inferior-pole renal infarction. Thus, the patient was immediately submitted to heart surgery. Conclusions Type A aortic dissection is a life-threatening disease in which early diagnosis and treatment are critical for survival. Occasionally it could mimic STEMI due to coronary involvement or dynamic obstruction of a coronary ostium. In our experience a bedside echocardiography performed before primary percutaneous coronary intervention (PCI) may confirm the clinical suspicious and avoid dangerous diagnostic delays.