Description/Etiology
Acute myocardial infarction (AMI; also referred to as heart attack) is the rapid development of myocardial necrosis
(i.e., death of an area of heart muscle) due to an inadequate supply of oxygen. AMI is most commonly caused by a
clot that blocks a coronary artery previously narrowed from a buildup of plaque. Additional causes of AMI include
coronary artery spasm, embolic infarction, arteritis, and cocaine-induced vasospasm. (For further information, see
Quick Lesson About… Acute Myocardial Infarction ).
Premenopausal women seem to have a lower risk of AMI than similarly-aged men; apparently because estrogen
helps keep low-density lipoprotein (LDL) cholesterol levels lower and high-density lipoprotein (HDL) cholesterol
levels higher than levels would be without estrogen, decreases fibrinogen levels, and relaxes coronary arteries. After
menopause, estrogen levels plummet, which results in an increased risk for AMI.
Women with AMI are more likely than men to present with “atypical” symptoms (see Signs and Symptoms/Clinical
Presentation, below); just 50% of women with AMI present with chest pain and women tend to delay seeking
treatment compared with men. AMI must be differentiated from heart failure, anxiety, aortic stenosis or dissection,
esophageal spasm or biliary colic, musculoskeletal or neurologic chest wall pain, pneumonia, and pericarditis.
Complications of AMI in women include recurrent or persistent chest pain, left ventricular aneurysm, stroke, heart
failure, thromboembolism, cardiac dysrhythmias, cardiac arrest, and death. Women presenting with AMI have a
higher risk of death and other complications than men presenting with AMI. The prognosis for women with AMI
varies and depends largely on the size, type, severity, and location of infarct and the amount of remaining functional
cardiac muscle. In general, prognosis worsens with increasing age and the presence of arrhythmias or major chronic
concomitant illnesses (e.g., diabetes mellitus [DM]) and improves with appropriate use of β-blockers or lipid-lowering
medications.
Treatment for AMI includes medication and/or surgery. Surgical treatment includes coronary artery bypass graft
(CABG), and coronary angiography with percutaneous transluminal coronary angioplasty (PTCA) with or without
stenting. Other coronary reperfusion procedures include intraaortic balloon counter pulsation, and transmyocardial
revascularization (TMR).