:If you do a Medline search on " myocardial infarction " & " diurnal ", you'll find about 125 references . " Onset of acute myocardial infarction ( AMI ) follows a diurnal periodicity, with a peak incidence between 6 : 00 a . m . and noon . " ( Impact of Ramipril on the Circadian Periodicity of Acute Myocardial Infarction, " The American Journal of Cardiology ", Volume 98, Issue 6, 15 September 2006, Pages 758-760 )-Nunh-huh 15 : 15, 23 June 2007 ( UTC)