ST-segment elevation associated with allergic reaction to echocardiographic contrast agent administration
A 60-year-old man was referred for contrast-enhanced dobutamine stress echocardiography (DSE) for detection of ischaemia. Two years before, the patient had an inferolateral myocardial infarction treated with a primary percutaneous coronary intervention and implantation of a drug-eluting stent in the right coronary artery (RCA). A few months before DSE, he complained of recurrence of typical angina pectoris due to a stenosis proximal to the stented segment in the RCA, which was successfully treated with implantation of a second drug-eluting stent (Fig.). However, few weeks later, he developed new atypical thoracic symptoms, for which he was referred for DSE[].\nAt the beginning of the procedure, the patient’s blood pressure was 135/75 mmHg, his heart rate was 79 beats/min and ECG showed sinus rhythm and right bundle-branch block (Fig.). Before starting the infusion of dobutamine, SonoVue® was administered to optimise visualisation of the left ventricle. One minute after administration of a 1 ml bolus of SonoVue®, the patient started complaining of nausea with profuse sweating and hypotension (100/45 mmHg). These signs were treated as an allergic reaction with clemastine (2 mg), hydrocortisone (100 mg), oxygen and saline infusion. Two minutes later, sudden severe chest pain occurred and the ECG showed ST-segment elevation in leads II, III, aVF and V2-V4, with ST-segment depression in V2-V4, I, and aVL, and total AV-nodal block (Fig.). During this episode, echocardiography showed akinesia of the inferior wall, whereas baseline echocardiography showed only mild mid-inferior hypokinesia. After 8 min (as measured on the monitor), the symptoms started to decrease and the ST segments normalised (Fig.). Immediate coronary angiography was performed showing a good patency of the stents in the RCA. However, a 50 % stenosis was observed proximally to the stented segment, which was interpreted as a possible coronary spasm (Fig.). No significant pathology was observed in the left coronary artery. Intravascular ultrasonography of the RCA was also performed and showed minimal neo-intimal hyperplasia (Fig.) with no significant stenosis. Further angiographic projections confirmed complete resolution of the spasm (Fig.). The patient was admitted to the coronary care unit and observed for 12 h. His recovery was uneventful and troponin T remained within normal ranges (0.016 μg/l).