title: Disappearance of Q waves following thrombolysis for acute myocardial infarction.
abstract: The development of Q waves on the surface electrocardiogram generally is considered indicative of myocardial infarction. Such Q waves are usually permanent, though may regress and disappear over months to years. Transient Q waves have been described during myocardial ischemia without evidence of infarction. More recently, Q waves have been noted to develop transiently during the acute phases of infarction, possibly representing stunned myocardium. In this case report, a patient with an evolving anterior myocardial infarction and new septal Q waves was treated with intravenous thrombolytic therapy. Three hours following treatment the patient was clinically improved, and the septal Q waves had been replaced by small but obvious R waves. Despite a large area of myocardium at risk of infarction on the initial electrocardiogram, the resultant infarction was enzymatically and echocardiographically small. Early Q waves in acutely evolving myocardial infarction may represent severely ischemic, rather than irreversibly damaged, myocardium which may still be salvaged with thrombolytic therapy.
authors.affiliation: Division of Cardiology, Wellesley Hospital, University of Toronto, Ontario.
authors.forename: M K
authors.initials: MK
authors.lastname: Gupta
authors.forename: P
authors.initials: P
authors.lastname: Teefy
authors.forename: J
authors.initials: J
authors.lastname: Ross
mesh_terms: D000328:Adult; D004562:Electrocardiography; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D013300:Streptokinase / Q000627:therapeutic use*; D015912:Thrombolytic Therapy; D013997:Time Factors
chemical_list: D013300:Streptokinase