a double-blind , randomized , crossover study was performed in 15 patients with stable angina to evaluate the effect of breathing carbon monoxide ( co ) , which raised the carboxyhemoglobin ( cohb ) from 1.09 % to 2.02 % , versus breathing compressed , purified air , which lowered the cohb from 1.07 % to 1.00 % on exercise duration until angina .
C0340288
stable angina
C0002962
angina