CONGRESS ABSTRACT

Introduction: Scombroid syndrome (SS) is a common cause of food poisoning caused by histamine-contaminated fish ingestion. Its typical manifestation includes flushing, cutaneous rash, diarrhea, dyspnea, tachycardia and hypotension, but some patients may experience acute chest pain associated with increased troponin levels, making myocardial infarction (MI) a possible differential diagnosis. Case report: A 54-years-old female patient, with history of minor stroke, was admitted to our cardiology ward for oppressive chest pain, hypotension and tachycardia occurred after tuna ingestion; she also had cutaneous rash, diarrhea and dyspnea, the electrocardiogram (ECG) showed sinus tachycardia with repolarization abnormalities in the inferior leads (figure 1) and blood tests detected a dynamic rising pattern of high sensitivity troponin with values slightly above the 99th percentile upper reference limit. Due to the suspect of SS, as first-line therapy parenteral anti-H1 antihistamines and glucocorticoids were administered, with rapid regression of symptoms. To exclude type 1 acute coronary syndrome, coronary angiography was performed and showed absence of coronaropathy (figure 2), consistent with the hypothesis of SS-induced type 2 MI. The patient was discharged asymptomatic, with normal ECG and normal biventricular systolic function 48 hours after her admission. Discussion: Type 2 MI occurs for a myocardial oxygen supply/demand mismatch; therefore it can be determined by prolonged hypotension and sustained tachycardia. In SS the main histamine systemic effect is general vasodilation, while in coronary vessels histamine can cause either constriction or relaxation by different mechanisms, according to histamine dose, vessels diameter, tone and relative localization. The hypothesis is that histamine poisoning could cause a combination of pre-capillary vasospasm and augmented capillary permeability, which could provoke a fall in perfusion pressure and consequently a generalized arteriolar constriction that ends in MI. Conclusion: MI is a rare complication of SS that can only partially be explained by hypotension and tachycardia induced oxygen supply/demand imbalance. Transient coronary vasospasm and microcirculation disfunction are thought to be the main pathomechanisms, making it appropriate to include this condition into the MINOCA group, when non-obstructive coronaropathy is detected on angiography.