title: Is an Abnormal ECG Just the Tip of the ICE-berg? Examining the Utility of Electrocardiography in Detecting Methamphetamine-Induced Cardiac Pathology.
abstract: BACKGROUND
  Methamphetamine use is escalating in Australia and New Zealand, with increasing emergency department attendance and mortality. Cardiac complications play a large role in methamphetamine-related mortality, and it would be informative to assess the frequency of abnormal electrocardiograms (ECGs) amongst methamphetamine users.
  
  
  OBJECTIVE
  To determine the frequency and severity of ECG abnormalities amongst methamphetamine users compared to a control group.
  
  
  METHODS
  We conducted a retrospective cohort analysis on 212 patients admitted to a tertiary hospital (106 patients with methamphetamine use, 106 age and gender-matched control patients). Electrocardiograms were analysed according to American College of Cardiology guidelines.
  
  
  RESULTS
  Mean age was 33.4 years, with 73.6% male gender, with no significant differences between groups in smoking status, ECG indication, or coronary angiography rates. Methamphetamine users were more likely to have psychiatric admissions (22.6% vs 1.9%, p<0.0001). Overall, ECG abnormalities were significantly more common (71.7% vs 32.1%, p<0.0001) in methamphetamine users, particularly tachyarrhythmias (38.7% vs 26.4%, p<0.0001), right axis deviation (7.5% vs 0.0%, p=0.004), left ventricular hypertrophy (26.4% vs 4.7%, p<0.0001), P pulmonale pattern (7.5% vs 0.9%, p=0.017), inferior Q waves (10.4% vs 0.0%, p=0.001), lateral T wave inversion (3.8% vs 0.0%, p=0.043), and longer QTc interval (436.41±31.61ms vs 407.28±24.38ms, p<0.0001). Transthoracic echocardiogram (n=24) demonstrated left ventricular dysfunction (38%), thrombus (8%), valvular lesions (17%), infective endocarditis (17%), and pulmonary hypertension (13%). Electrocardiograms were only moderately sensitive at predicting abnormal TTE.
  
  
  CONCLUSIONS
  Electrocardiographic abnormalities are more common in methamphetamine users than age and gender-matched controls. Due to the high frequency of abnormalities, ECGs should be performed in all methamphetamine users who present to hospital. Methamphetamine users with abnormal ECGs should undergo further cardiac investigations.
authors.affiliation: Department of Cardiology, St Vincent's Hospital Melbourne, Vic, Australia. Electronic address: elizabeth.paratz@svha.org.au.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Paratz
authors.affiliation: Department of Cardiology, St Vincent's Hospital Melbourne, Vic, Australia.
authors.forename: Jessie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Cardiology, St Vincent's Hospital Melbourne, Vic, Australia.
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Sherwen
authors.affiliation: Department of Cardiology, St Vincent's Hospital Melbourne, Vic, Australia.
authors.forename: Rose-Marie
authors.initials: RM
authors.lastname: Scarlato
authors.affiliation: Department of Cardiology, St Vincent's Hospital Melbourne, Vic, Australia.
authors.forename: Andrew I
authors.initials: AI
authors.lastname: MacIsaac
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006331:Heart Diseases / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D008694:Methamphetamine
keywords: Electrocardiograms; Methamphetamines