Information on Myocardial Infarction
A heart attack or myocardial infarction (MI) is an acute life-threatening disease of the heart. The blood supply to the heart is interrupted causing parts of the heart muscle to die.
In 2006 some 350,000 deaths were due to coronary heart diseases, some 65,000 due to acute MI. Coronary heart diseases are the leading cause of death, in particular in the elderly population (over 65 years).
Symptoms:
Cardinal symptom is an acute sudden chest pain lasting in most cases for more than 20 minutes which may radiate to shoulders, arms, the lower jaw, and the epigastrum. Further accessory symptoms may be sweating and nausea. During the acute phase of a myocardial infarction dangerous heart arrhythmias may occur.
Causes:
The majority of heart attacks develop in the course of a coronary heart disease (CHD). Atherosclerotic alterations of the blood vessels often accompanied by additional blood clots cause a sudden restriction in the blood supply in a coronary vessel. If the blood supply is completely interrupted the myocardial muscle begins to die after 15-30 minutes. Further (rare) causes for an infarct might be long-lasting spasms, bleedings or hemorrhaging, tumors of the heart, and ruptures in the inner wall of a vessel. This also leads to the occlusion of a coronary vessel followed by an infarct.
Risk Factors:
Main risk factors are old age, tobacco smoking, high alcohol intake, diabetes mellitus, high blood pressure, and genetic predisposition. Further risk factors are fat metabolism disorders, obesity, malnutrition, and lack of physical exertion. Triggering factors may be sudden stress or stress situations with extreme variations in blood pressure. Examinations showed that further risk factors, as e.g., a low level of vitamin D3 or air pollution may enhance the risk of a myocardial infarction.
See also website "Herzschlag-Info" (heartbeat info, in german only): www.helmholtz-muenchen.de/herzschlag-info/