Acute myocardial infarction. 
Acute myocardial infarction is a common disease with serious consequences in mortality, morbidity, and cost to the society.  Coronary atherosclerosis plays a pivotal part as the underlying substrate in many patients.  In addition, a new definition of myocardial infarction has recently been introduced that has major implications from the epidemiological, societal, and patient points of view.  The advent of coronary-care units and the results of randomised clinical trials on reperfusion therapy, lytic or percutaneous coronary intervention, and chronic medical treatment with various pharmacological agents have substantially changed the therapeutic approach, decreased in-hospital mortality, and improved the long-term outlook in survivors of the acute phase.  New treatments will continue to emerge, but the greatest challenge will be to effectively implement preventive actions in all high-risk individuals and to expand delivery of acute treatment in a timely fashion for all eligible patients.