Identifying the ICE-Hearts: Examining the Utility of Electrocardiography in Screening for Methamphetamine-Induced Cardiac Pathology

Abstract

Background: Cardiac complications play a large role in increasing methamphetamine-related mortality. Purpose: 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 abuse, 106 age and gender-matched control patients). ECGs were analysed according to American College of Cardiology guidelines, and compared to echocardiographic (TTE) findings. Results: Mean age was 33.4 years, with 73.6% male gender, and 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). TTE (n=24) demonstrated left ventricular dysfunction (38%), thrombus (8%), valvular lesions (17%), infective endocarditis (17%), and pulmonary hypertension (13%). ECG was only moderately sensitive at predicting abnormal TTE. Conclusion: ECG abnormalities are more common in methamphetamine users than age and gender- matched controls. We suggest ECGs should be performed in all methamphetamine users presenting to hospital. Methamphetamine users with abnormal ECGs should be considered for further cardiac investigations.