Electrocardiographic abnormalities in methamphetamine abusers.
OBJECTIVE
Although many adverse cardiovascular outcomes are mentioned in conjunction with methamphetamine use, a causal relationship between methamphetamine use and arrhythmia or cardiomyopathy has not been demonstrated in man. Clinical experience with methamphetamine users suggested a higher incidence of electrocardiographic abnormalities. This study seeks to quantify that incidence, among subjects enrolled in a study of adults with methamphetamine dependence.


METHODS
Electrocardiograms obtained during screening in a previous clinical trial were examined. The study population (n = 158) of adults with methamphetamine dependence [Diagnostic and Statistical Manual version IV (DSM IV-TR)] was drawn from five sites across the United States, recruited in the interval 2002-03.


RESULTS
A significant variance from the normal population was noted in the electrocardiograms of the study cohort. Among the abnormalities was a prolongation of the QTc beyond 440 ms in 27.2% of the group. QTc prolongation to this extent poses a particular risk for ventricular arrhythmias, most notably torsades de pointes.


CONCLUSIONS
We believe that this is the first demonstration of clinically significant QTc prolongation in a methamphetamine-using population, and that this has implications for the types of arrhythmias for which this population is at risk. It may further provide a marker for risk of cardiomyopathy. The fact of electrocardiographic changes with potential cardiac risks may be useful in a motivational interviewing approach, in challenging the methamphetamine user's basis for continuing use.
Haning
William
W
Department of Psychiatry, University of Hawai'I John A. Burns School of Medicine, 1356 Lusitana Street, 4th Floor, Honolulu, HI 96813, USA. haning@hawaii.edu
Goebert
Deborah
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D019969:Amphetamine-Related Disorders / Q000150:complications* / Q000503:physiopathology; D001145:Arrhythmias, Cardiac / Q000139:chemically induced*; D000697:Central Nervous System Stimulants / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D008875:Middle Aged
D000697:Central Nervous System Stimulants; D008694:Methamphetamine