Electrocardiographic diagnosis of myocardial infarction and ischemia during cardiac pacing.
For the diagnosis of myocardial infarction (MI) using the QRS complex, the ECG provides only a low sensitivity (25%) but high specificity (close to 100%), but one cannot determine the age of an MI from the QRS complex. Although one cannot determine with certainty the age of an MI (hours, days or even years) from a single ECG, the presence of primary ST-segment abnormalities strongly suggests the diagnosis of acute MI or severe ischemia and the possible need for emergency revascularization. For acute MI, ST elevation>or=5 mm in predominantly negative QRS complexes is the best marker with a sensitivity of 53%, and specificity of 88%. A recent investigation suggests that T wave abnormalities from ischemia can be differentiated from those caused by cardiac memory related to pacing.
Barold
S Serge
SS
Division of Cardiology, University of South Florida College of Medicine and Tampa General Hospital, Tampa, FL, USA. ssbarold@aol.com
Herweg
Bengt
B
Curtis
Anne B
AB
D002304:Cardiac Pacing, Artificial; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000628:therapy; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000628:therapy