A case report of Kounis syndrome presenting with coronary angina pectoris and coronary microcirculatory disturbance, resulting in takotsubo cardiomyopathy-like changes.

BACKGROUND: Kounis syndrome is an allergic syndrome leading to acute coronary syndromes (ACS). It includes coronary spasm angina (CSA), plaque erosion or rupture, and coronary stent thrombosis. Takotsubo cardiomyopathy is a myocardial disease without significant stenosis of the coronary arteries and is said to include coronary microvascular dysfunction (CMD) and CSA in its background.

CASE SUMMARY: A 63-year-old woman was urgently brought to our hospital due to chest tightness and loss of consciousness after the appearance of generalized urticaria. She was in anaphylactic shock and her ECG suggested ACS. Emergency coronary angiography showed no significant stenosis and left ventriculography showed takotsubo cardiomyopathy-like wall motion. The diagnosis of Kounis syndrome type I was made. The simultaneous binuclear cardiac scintigraphy of 99mTc-tetrofosmin and 123I-BMIPP showed atypical images of takotsubo cardiomyopathy. The evaluation of coronary microvascular function showed CMD and the acetylcholine (ACh) stress test showed multivessel CSA. We started a calcium channel blocker, isosorbide mononitrate, and antihistamines. She was discharged from the hospital after cardiac function improved and has remained stable without any recurrence during one year of outpatient follow-up.

DISCUSSION: There are few reports of an invasive evaluation in the subacute phase of Takotsubo cardiomyopathy-like clinical presentation. We report a case of takotsubo-like wall motion abnormality due to CSA and CMD in a patient with Kounis syndrome. Simultaneous binuclear myocardial scintigraphy, assessment of the coronary microcirculation, and ACh stress test were useful in the diagnosis, and the coexistence of CSA and CMD suggested her clinical images similar to takotsubo cardiomyopathy.