FREQUENCY AND TYPE OF ELECTROCARDIOGRAPHIC ABNORMALITIES IN COCAINE ABUSERS (ELECTROCARDIOGRAM IN COCAINE ABUSE)

Electrocardiographic abnormalities of 200 asymptomatic, chronic cocain e abusers (aged less than or equal to 45 years, 69% black) admitted fo r rehabilitation (group 1) were compared with 38 cocaine abusers treat ed in the emergency room (group 2), 21 cocaine abusers who died sudden ly (group 3), and 425 control subjects from the general population. In group 1, 39% of electrocardiograms were abnormal: Increased QRS volta ge was noted in 27%, ST elevation in 22%, ST-T changes in 17%, and pri or myocardial infarction in 3%. Increased QRS voltage (35% vs 10%, p = 0.00007) and ST elevation (26% vs 13%, p = 0.0278) were more prevalen t in blacks than in whites. With use of Minnesota coding electrocardio grams in group 1 were compared with those of 141 black and 284 white m en (aged <40 years) from the general population. ST elevation was more prevalent in both black (22% vs 8%, p = 0.00073) and white (15% vs 1% , p <0.00001) cocaine abusers than in the general population. Compared with group 1, group 2 had higher prevalence of sinus tachycardia (16% vs 1%, p = 0.0002), supraventricular tachycardia (5% vs O%, p = 0.024 ), ST-T changes (34% vs 17%, p = 0.0164), and QTc >440 ms (26% vs 4%, p = 0.00003); mean QTc was also greater amend group 2 subjects (427 +/ - 38 vs 404 +/- 19 ms, p <0.0001). In group 3, QTc was >440 ms in 6 of 8 subjects (75%) with 12-lead electrocardiograms. Mean QTc was greate r in group 3 (457 +/- 29 ms) than in group 1 (404 +/- 19 ms p <0.0001) acid group 2 (427 +/- 38 ms, p = 0.002). Electrocardiographic abnorma lities are common amend asymptomatic, chronic cocaine abusers, with a higher prevalence in blacks. Curing acute cocaine abuse, abnormalities are more prevalent and QT is prolonged.