Cardiogenic shock induced by cocaine in swine with normal coronary arteries.
OBJECTIVE
The aim was to test the hypothesis that acute intravenous cocaine administration can cause coronary microvascular constriction culminating in myocardial ischaemia and cardiogenic shock.


METHODS
Systemic haemodynamic variables and coronary blood flow were measured in 14 Yorkshire swine at baseline and following intravenous administration of 1, 3, and 10 mg.kg-1 of cocaine. Epicardial coronary artery diameter was measured from coronary arteriograms and coronary flow velocity was recorded with a Doppler flow wire.


RESULTS
Cocaine produced a decrease in mean arterial pressure (65%), cardiac output (80%), and stroke volume (80%), and an increase in pulmonary artery diastolic pressure (60%). Although coronary blood flow decreased by 70%, epicardial coronary cross sectional area decreased by only 37-45%. Pretreatment with prazosin did not abolish the decrease in coronary blood flow. After administration of 10 mg.kg-1 of cocaine, five of 14 animals developed myocardial ischaemia and cardiogenic shock, culminating in ventricular fibrillation and death.


CONCLUSIONS
In anaesthetised Yorkshire swine, cumulative intravenous doses of cocaine caused a significant reduction in coronary blood flow resulting in myocardial ischaemia, which cannot be attributed to epicardial vasoconstriction alone. This suggest that cocaine-induced coronary ischaemia may result from microvascular constriction, which is only partially prevented by alpha 1 blockade. In addition, direct toxic effects of cocaine on the myocardium may also contribute to the development of cardiogenic shock.
Núñez
B D
BD
Cardiovascular Division, Beth Israel Hospital, Boston, MA 02215.
Miao
L
L
Kuntz
R E
RE
Ross
J N
JN
Gladstone
S
S
Baim
D S
DS
Gordon
P C
PC
Morgan
J P
JP
Carrozza
J P
JP
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D003042:Cocaine / Q000633:toxicity*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D008297:Male; D017202:Myocardial Ischemia / Q000139:chemically induced; D011224:Prazosin / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D012770:Shock, Cardiogenic / Q000139:chemically induced*; D013318:Stroke Volume / Q000187:drug effects; D013552:Swine
D003042:Cocaine; D011224:Prazosin