Differential diagnosis of ST segment elevation: Important and stressful diagnosis in an era of thrombolysis

In an era of coronary thrombolysis, quick and accurate differentiation of acute myocardial infarction from other mimicking entities is critical since thrombolysis in its early course is beneficial. Differential diagnosis of ST segment elevation in an electrocardiogram includes acute myocardial infarction, left ventricular aneurysm, Prinzmetal's angina, acute pericarditis and early repolarization. Less commonly, myocarditis, left ventricular hypertrophy and left bundle branch block pattern can cause ST segment elevation. The presence or absence of PR segment depression, q wave and reciprocal and evolutional changes should be evaluated as well as shape and location of ST segment elevation, ST segment axis and ST/T ratio. Administration of nitrate resolves electrocardiographic changes due to coronary spasm. Evaluation of left ventricular wall motion by echocardiogram is helpful.