Be Aggressive in Considering Reperfusion Therapy in Acute Myocardial Infarction
Anthony D. Slonim MD, DrPH
Cardiovascular disease is a dominant cause of morbidity and mortality in the United States and acute myocardial infarction (MI) is one of the major underlying etiologies. Acute MI is a medical emergency that is precipitated when coronary occlusion leads to ischemia and then necrosis of cardiac myocytes. The necrosis will often precipitate a cardiac arrhythmia (e.g., ventricular fibrillation), which is a major cause of death for patients presenting in the acute phase. The diagnosis of an acute MI is based on the patient’s history and diagnostic testing, including an electrocardiogram (ECG) and serum enzymes. The faster the diagnosis can be made and the occlusion reversed, the more likely the patient is to salvage myocardial tissue and benefit from improved outcomes.
Watch Out For
In nondiabetic patients, the major symptom of acute MI is pain. This pain is usually described as severe. It is located in a retrosternal area and may radiate to either the arms or neck. The characteristic quality of the pain is described as pressurelike or bandlike; however, other descriptions including burning, aching, and crushing have also been used. The pain usually lasts beyond 20 to 30 minutes and does not dissipate. Associated symptoms include nausea, vomiting, shortness of breath, dizziness, and diaphoresis.
In the setting of a possible acute MI, the ECG is a readily available, noninvasive, easy-to-obtain diagnostic test that has excellent sensitivity and specificity. The ECG provides information on the distribution of changes and the impact on cardiac rhythm. The pattern of ST-segment elevation representing a “current of injury” is usually associated with acute MI and implies a coronary occlusion. This is helpful for triaging for strategies of reperfusion.