Editing Anaphylaxis (section)

===Cardiovascular===
While [[Tachycardia|a fast heart rate]] caused by low blood pressure is more common,<ref name=Aus06/> a [[Bezold–Jarisch reflex]] has been described in 10% of people, where a [[Bradycardia|slow heart rate]] is associated with [[Hypotension|low blood pressure]].<ref name=CEA11/> A drop in [[blood pressure]] or [[Shock (circulatory)|shock]] (either [[Distributive shock|distributive]] or [[Cardiogenic shock|cardiogenic]]) may cause the feeling of lightheadedness or [[Unconsciousness|loss of consciousness]].<ref name=Cardio08/> Rarely very low blood pressure may be the only sign of anaphylaxis.<ref name=Shock10/>

[[Angina pectoris|Coronary artery spasm]] may occur with subsequent [[myocardial infarction]], [[Cardiac dysrhythmia|dysrhythmia]], or [[cardiac arrest]]<!--  even in the absence of epinephrine use -->.<ref name=World11/><ref name=Review09/> Those with underlying coronary disease are at greater risk of cardiac effects from anaphylaxis.<ref name=Cardio08/> The coronary spasm is related to the presence of [[histamine]]-releasing cells in the heart.<ref name=Cardio08/>