A potential association between myocardial ischemia and epinephrine for anaphylaxis

A previously healthy 60-year-old man presented to our emergency department with anaphylactic shock. We initiated fluid resuscitation with Ringer's lactate solution; injected 0.3 mg epinephrine intramuscularly; and administered d-chlorpheniramine maleate 5 mg, famotidine 20 mg, and methylprednisolone 80 mg intravenously. His symptoms resolved within 10 min. Thirty minutes after the epinephrine injection, he complained of sudden chest discomfort. Physical examination provided no evidence of anaphylaxis. The 12-lead electrocardiogram (ECG) showed ST-segment depression on leads II, III, aVF, and V3-6. Transthoracic echocardiography revealed normal ventricular contraction. After administration of 0.3 mg of sublingual nitroglycerin, his chest pain resolved immediately and his ECG normalized. A coronary angiogram showed normal coronary artery perfusion. The next day, his high-sensitivity troponin I was slightly elevated. We suspected that he had myocardial ischemia caused by coronary artery spasm. The symptoms of biphasic reaction of anaphylaxis are inconsistent, and using epinephrine for myocardial ischemia following anaphylaxis may aggravate the condition. Nonetheless, epinephrine is the drug of choice for treating anaphylaxis with critical airway, respiratory, and circulatory compromise. Thus, physicians should not hesitate to use epinephrine for patients who present with life-threatening conditions due to suspected anaphylaxis. Physicians should observe patients closely following epinephrine administration, and if they develop some symptoms, should carefully examine the patients because the treatments of anaphylaxis and myocardial ischemia differs. Physicians should be alert to the risk of myocardial ischemia after treatment of anaphylaxis, especially following epinephrine administration.