Carboxyhemoglobin (COHb) levels were measured in patients who came to
an emergency department complaining of acute chest pain. For subjects
not receiving prior oxygen therapy, those with cocaine-related chest p
ain (n = 10) had a higher mean COHb level than a comparison group (n =
28) with nonischemic chest pain (4.50 +/- 2.40 vs 2.73 +/- 0.66; p <
0.05). Four of the seven (57 percent) who smoked crack had COHb levels
greater than 4.5 percent, while only one of six (17 percent) smokers
of only tobacco had such a level. These findings suggest an additional
mechanism, the formation of COHb, which could aggravate cocaine-induc
ed cardiotoxicity.