title: Incidence and significance of ventricular tachycardia and fibrillation in the absence of hypotension or heart failure in acute myocardial infarction treated with recombinant tissue-type plasminogen activator: results from the Thrombolysis in Myocardial Infarction (TIMI) Phase II trial.
abstract: OBJECTIVE
  The purpose of this study was to determine the incidence of ventricular tachycardia and fibrillation without hypotension or heart failure after treatment with recombinant tissue-type plasminogen activator (rt-PA), anatomic correlates of their development, the effect of immediate intravenous metoprolol on their occurrence and the outcome of patients with these arrhythmias.
  
  
  BACKGROUND
  Malignant arrhythmias after thrombolytic therapy have been reported to occur as a result of coronary reperfusion, which is associated with reduced mortality in patients receiving thrombolytic therapy.
  
  
  METHODS
  We analyzed data from 2,546 patients in the Thrombolysis in Myocardial Infarction (TIMI) Phase II trial without congestive heart failure or hypotension during the 1st 24 h after study entry. Forty-nine patients (1.9%) developed sustained ventricular tachycardia or ventricular fibrillation within 24 h of study entry (group 1), and 2,497 patients (98.1%) did not (group 2).
  
  
  RESULTS
  Baseline characteristics and admission laboratory values were similar in the two groups. In patients undergoing protocol angiography 18 to 48 h after rt-PA, the infarct-related artery was patient in a greater percent of group 2 patients (87% [1,015 of 1,169]) than group 1 patients (68% [15 of 22], p = 0.01), although angiography was performed less frequently in group 1 than in group 2. More group 1 than group 2 patients died within 21 days (20.4%) (1.6%, p < 0.001). For patients surviving to 21 days, there was no difference in mortality between patients in the two groups in the following year.
  
  
  CONCLUSIONS
  Ventricular tachycardia and fibrillation are not markers for reperfusion after thrombolytic therapy. These arrhythmias are associated with occlusion, not patency, of the infarct-related artery. Early mortality is increased in patients who develop ventricular tachycardia and fibrillation, even in the absence of congestive heart failure and hypotension.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: P B
authors.initials: PB
authors.lastname: Berger
authors.forename: N A
authors.initials: NA
authors.lastname: Ruocco
authors.forename: T J
authors.initials: TJ
authors.lastname: Ryan
authors.forename: M M
authors.initials: MM
authors.lastname: Frederick
authors.forename: P J
authors.initials: PJ
authors.lastname: Podrid
mesh_terms: D005260:Female; D006333:Heart Failure / Q000453:epidemiology*; D006801:Humans; D007022:Hypotension / Q000453:epidemiology*; D015994:Incidence; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy*; D017180:Tachycardia, Ventricular / Q000453:epidemiology* / Q000209:etiology; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D010959:Tissue Plasminogen Activator; D008790:Metoprolol