57 ischemic heart scombroid syndrome: further evidence from all over the world

Abstract Objective Scombroid syndrome (SS) is a long-standing poisoning illness caused by ingestion of improperly stored fish food (usually tuna fish) contaminated by Gram-negative bacteria. The main pathogenetic feature is toxicity by the high histamine (and/or other toxin) levels within the fish muscle. Scombroid syndrome accounts for approximately 5% of food toxicities at emergency department in the USA. It consists of gastrointestinal symptoms, sickness, at times (head) rash or flushing, peppery taste, hypotension, and other symptoms. Cardiovascular complications are infrequent, but acute coronary syndromes (ACSs) have been described in some patients on admission to hospital. We identified those cases as with ischemic heart scombroid syndrome (IHSS). Methods An accurate literature search for IHSS in case series and single reports, published as by the end of July 2022, was performed. Herein main clinical features are summarized. Results From 1997 to 2022, 18 studies were found describing 25 patients aged 42±15 years, 14 women (56%), likely to have IHSS. Countries of origin are depicted in the Figure nearby. Apart from typical clinical presentation of SS, chest pain, oppression and hypotension were complained by almost all patents. Symptoms and signs of ACS started 10 to 180 minutes from the meal. Four patients (mostly before 2015) required advanced life support or mechanical ventilation. Widespread ST-depression (first in the inferior leads) was the most frequently reported ECG feature (approximately in 90% of cases). Hospitalization was required for unstable patients or those admitted for coronary angiography. However, this latter was performed only in 10 cases (40%), and only in 3 (12%) a culprit lesion was identified and treated. Therapy consisted with antihistamine drugs, fluids and circulatory support, symptomatic drugs, and steroids in some cases. All patients were discharged from hospital with uneventful follow-up. Conclusions To date, 25 published cases of IHSS have been recognized, mostly from Italy, but reports are from all over the world. As in typical SS, myocardial ischemia begins shortly after raw or cocked (tuna) fish ingestion. However, due to unfamiliarity with the syndrome, diagnostic misinterpretation is possible. IHSS can be classified as a transient (usually benign) ACS, caused by coronary vasospasm in response to a nitroxide-mediated histamine-induced tissue hypoperfusion, in a similar way to type-I Kounis syndrome. Based on current knowledge, coronary angiography is mandatory in patients with a history of coronary artery disease and/or allergic diathesis, persistent symptoms or unresponsive to emergency treatment.