Mechanism: spasm of a coronary artery, originally ascribed to release of histamine or other inflammatory mediators. Episodes may occur without vasospasm.
The triggering allergen may include:
(1) medication (penicillin antibiotic, diclofenac, mesalamine, lepirudin, etc)
(2) bee or wasp sting
(3) latex allergy
(4) food allergy
(5) exercise-induced anaphylaxis
(6) nickel allergy
(7) iodinated contrast material
(8) endovascular device
Features:
(1) The patient experiences an acute onset of angina.
(2) The onset of angina follows exposure to an allergen, with or without anaphylaxis.
(3) Coronary arteries may be normal or there may be evidence of pre-existing coronary artery disease.
(4) Variable elevation of serum troponin concentration.
(5) Variable elevation of serum tryptase concentration.
The diagnosis is more likely to be recognized if there is no previous history of coronary artery disease, the patient is young, and there is anaphylaxis.
Complications:
(1) acute myocardial infarction (allergic myocardial infarction)
(2) delayed onset of Takotsubo cardiomyopathy
