Rare case of anaphylaxis causing st elevation myocardial infarction-epinephrine better avoided, is myocardial bridge a trigger?
34 year old female with known history of sero positive rheumatoid arthritis presented to the emergency department with history of syncope within an hour of consumption of red meat (beef) to which she was known to be allergic.
On presentation she had a patent airway and was not in respiratory distress. HR 102 bpm , RR 20 per minute , BP 70/50 mm Hg , Saturation 98% in room air . She was diagnosed to be in anaphylactic shock
As per the current guidelines intramuscular Epinephrine was about to be administered ,when significant ST depression in limb leads were noticed on the cardiac monitor. Epinephrine administration was deferred and she was treated with Intravenous fluid bolus w and i.v hydrocortisone along with i.v H1 receptor antagonist and i.v H2 receptor antagonist .
Patient responded well to treatment and a 12 lead ECG was obtained which showed evidence of probable LMCA occlusion (ST depressions in lead I, II, III ,aVF ,v3 to v6, ST elevation in aVR and V1 ) .She was administered oral loading dose of antiplatelets and Cath Lab was alerted.Senior cardiologist assessed the patient in the emergency department and a bed side echo was done , which was completely normal.
Since the patient had improved hemodynamically and there was no chest pain a repeat ECG was done 20 minutes after the first which turned out to be completely normal.
In view of the significant ECG changes a coronory angiogram was done which showed a normal LMCA , LCX and RCA with a myocardial bridge in the mid LAD .
Considering few case reports of cardiac arrests following administration of epinephrine in Kounis syndrome it would be preferable to look at the ecg changes in anaphylaxis before administering epinephrine.
There is one case report suggesting myocardial bridge as a possible trigger for Kounis syndrome . But in the above case the myocardial bridge was found in the mid LAD segment but ECG changes were suggestive of occlusion in the left main coronory artery and not in the LAD .
Anaphylaxis presenting as STelevation MI should be carefully assessed and treated with extreme caution.
