Purpose of review: In severe anaphylaxis, the cardiovascular system is often heavily involved. Preexisting cardiovascular disease may therefore influence the course of anaphylaxis in a negative way.
Recent findings: Systemic mastocytosis and elevated baseline serum tryptase are associated with severe and fatal anaphylaxis to hymenoptera stings. This is due to an increased number of cardiac mast cells resulting in high concentrations of cardiotoxic mast cell mediators in cardiac tissue during anaphylaxis. Severe anaphylaxis in coronary heart disease, in particular, is explained by an increased load of cardiac mast cells together with coronary stenosis favouring myocardial hypoxia. Contraindications for the use of medications for cardiac disease in patients with anaphylaxis, especially β-blockers, have been questioned by epidemiologic studies considering the positive effects of these drugs on much more prevalent cardiac diseases.
Summary: Preexisting cardiovascular disease, mastocytosis and elevated baseline serum tryptase are risk factors for fatal anaphylactic reactions or lasting morbidity due to myocardial or cerebrovascular infarction induced by anaphylaxis. Life-saving cardiac medications like β-blockers may increase the severity of anaphylaxis. Since life-threatening cardiovascular diseases are much more frequent than anaphylaxis, the relative risk of either disease with and without these drugs must be analyzed carefully together with the cardiologist.