Preexisting cardiovascular disease may worsen the course of anaphylaxis. This is illustrated based on the example of Hymenoptera venom allergy. Fatal sting anaphylaxis is most often observed in elderly patients. During autopsy preexisting cardiovascular disease is frequently found. Preexisting cardiovascular disease in patients with anaphylaxis may also cause lasting morbidity, e.g. cerebral or myocardial infarction. Heart medications, notably beta-blockers und ACE-inhibitors may worsen the course of anaphylactic reactions due to their pharmacologic effects. Since cardiovascular diseases are much more frequent than anaphylaxis and these medications are very effective, these drugs cannot be substituted in patients with both diseases without a careful risk analysis. Epinephrine is the drug of first choice for treatment of anaphylaxis. It may however, especially following rapid intravenous administration, cause severe arrhythmias or myocardial infarction. Adrenaline should therefore preferably be given intramuscularly, or by slow intravenous infusion.