The ECG manifestations of NQMI are ST segment elevation or depression and T wave changes. Because these repolarization abnormalities are not specific for AMI, this diagnosis has to be confirmed by non-ECG techniques. Some authors include in NQMI patients without typical ST-T wave changes. buy asthma inhalers
ST segment Elevation: According to Huey et al and others, 40 to 60 percent of patients with ST segment elevation only develop a NQMI which should be considered in patients who have less prominent ST segment elevation (0.1 to 0.2 mV), a smaller number of involved leads or a history of prior myocardial infarction.
Acute Myocardial Infarction
The diagnosis of AMI is not difficult in a patient with ischemic chest pain lasting for 30 minutes or longer in whom the initial ECG shows ST segment elevation with or without pathologic Q waves. In patients with ischemic chest pain and repolarization abnormalities, intraventricular conduction defects, or left ventricular hypertrophy, the diagnosis of AMI is less certain and has to be confirmed by elevated serum creatine kinase and its MB fraction (CK-MB) or nuclear perfusion studies.
Newer angiographic, anatomic, and metabolic studies support the view that acute coronary syndromes, which include acute myocardial infarction, unstable angina and ischemic sudden death, are different manifestations of ruptured atheroma with superimposed thrombosis and release of vasoactive substances. The clinical manifestation of acute coronary syndromes is determined by the size of the atheroma, the extent and duration of the occlusion (partial vs occlusive thrombus), collateral circulation, spontaneous reperfusion, and coronary artery tone. Buy Asthma Inhalers Online