title: Incidence and type of cardiac arrhythmias in critically ill patients: a single center experience in a medical-cardiological ICU.
abstract: OBJECTIVE
  To determine the frequency and types of significant, sustained arrhythmias in a mixed ICU.
  
  
  METHODS
  Prospective, observational study in a medical-cardiological-postoperative ICU at a university hospital.
  
  
  METHODS
  133 consecutive patients with arrhythmias.
  
  
  RESULTS
  All patients had continuous ECG monitoring and automatic arrhythmia detection. We assessed: (a) sustained (>30 s) tachyarrhythmias; (b) all tachyarrhythmias requiring therapy; (c) bradycardias of fewer than 40 beats/min or requiring intervention. There were 310 arrhythmia episodes: 278 tachyarrhythmias (108 narrow-QRS complex, 168 wide-QRS complex; 179 regular, 97 irregular) and 32 bradycardias. Of the 278 tachycardias in 54 patients, 135 (48.6%) were ventricular. There were 13 episodes of torsade de pointes (4.67%) in five patients. Of the 278 tachycardiac episodes 83 were atrial fibrillation (29.8%, 63 patients), 10 atrial flutter (3.6%, 8 patients), 21 supraventricular tachycardias (7.55%, 7 patients), and 2 ectopic junctional tachycardia (0.72%, 1 patient). The number of patients showing significant arrhythmias was comparable over the years (11-12/1996: 4/28 [14.3], 1997: 52/302 [17.2%], 1998: 55/286 [19.2%], 22/140 [15.7%] 1-7/1999). The ICU stay was significantly longer in arrhythmia patients than in 623 patients without arrhythmias (median 4 vs. 14 days), and there was a trend towards higher mortality (40/133, 30.8%, vs. 132/623, 21.2%, P=0.061, log-rank).
  
  
  CONCLUSIONS
  Only one-fifth of patients in this mixed ICU had significant arrhythmias, taking a contemporary definition of arrhythmias. Ventricular tachycardia and atrial fibrillation were the most frequent arrhythmias.
authors.affiliation: Department of Cardiology, University of Vienna, Allgemeines Krankenhaus, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Reinelt
authors.forename: G D
authors.initials: GD
authors.lastname: Karth
authors.forename: A
authors.initials: A
authors.lastname: Geppert
authors.forename: G
authors.initials: G
authors.lastname: Heinz
mesh_terms: D018806:APACHE; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D001919:Bradycardia / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016638:Critical Illness / Q000145:classification* / Q000453:epidemiology*; D004562:Electrocardiography; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units / Q000706:statistics & numerical data* / Q000639:trends; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D017063:Outcome Assessment, Health Care; D010343:Patient Admission / Q000706:statistics & numerical data / Q000639:trends; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013610:Tachycardia / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy