Mj. Eisenberg et al., LEFT-VENTRICULAR FUNCTION IMMEDIATELY AFTER INTRAVENOUS COCAINE - A QUANTITATIVE 2-DIMENSIONAL ECHOCARDIOGRAPHIC STUDY, Journal of the American College of Cardiology, 22(6), 1993, pp. 1581-1586
Objectives. We tested the hypothesis that intravenous cocaine, in dose
s commonly self administered in nonmedical settings, causes acute myoc
ardial ischemia and left ventricular dysfunction. Background. Cocaine
induced cardiac complications are responsible for a growing number of
deaths in young people, but the mechanism by which cocaine induces the
se complications is unclear. Methods. We performed 12-lead electrocard
iography and quantitative two dimensional echocardiography in 20 subje
cts before and after single intravenous doses of high dose cocaine (1.
2 mg/kg body weight), low dose cocaine (0.6 mg/kg) and placebo. Result
s. At 2 to 7 min after cocaine administration, the rate pressure produ
ct was increased significantly from baseline (high dose 73%, low dose
63%, placebo 8%, p < 0.001 for either dose vs. placebo). During this t
ime, electrocardiography demonstrated dose related nonspecific changes
(high dose in 14 of 20 subjects, low dose in 9 of 20 subjects, placeb
o in 2 of 20 subjects, p < 0.002 for either dose vs. placebo). In cont
rast, echocardiography showed that the frequency of hyperdynamic left
ventricular wall segments doubled after high dose cocaine compared wit
h placebo (34% [108 of 318] vs. 16% [51 of 319], respectively, p = 0.0
001) but that there was no change in either left ventricular ejection
fraction (high dose 66 +/- 9%, placebo 67 +/- 6%, p = NS) or wall moti
on score index (high dose 0.67 +/- 0.44, placebo 0.85 +/- 0.30, p = NS
). Conclusions. We conclude that intravenous cocaine, in doses commonl
y self-administered in nonmedical settings, does not cause acute myoca
rdial ischemia or left ventricular dysfunction. We speculate that coca
ine induced cardiac complications are caused by idiosyncratic coronary
artery vasospasm, by exceptionally high dosages or by cocaine-induced
coronary artery thrombosis.