There is an expanding literature that suggests that acute myocardial infarction and death from coronary artery disease can be triggered by a number of natural as well as man­made triggers. Natural triggers include circadian fluctuations (with an increase in myocardial infarction and cardiac death in the morning associated with the first few hours after the wake­up time¹), seasonal fluctuations (with an increase in cardiac events during the winter months)² and natural disasters (such as earthquakes³ and blizzards).

MAN-MADE TRIGGERS

Man-made triggers have been studied in detail and include heavy and moderate physical activity, emotional upset⁴ (including anger, as described in the accompanying manuscript by Strike et al⁵), overeating, lack of sleep, sexual activity, and the use of cocaine and other illicit substances.⁴ Certain man-made events may trigger cardiac events. For example, we recently observed that there was an increase in ischaemic heart disease death rates during the millennium celebration of the New Year versus other New Years’ celebration.⁶ Another report of an increase in cardiac events induced by a man-made event was the increase in acute myocardial infarction and sudden death reported in Israel at the time of Iraqi missile attacks.⁷ We were surprised to learn that some man-made unnatural disasters that we hypothesised might be associated with an increase in death due …