The first 3 patients randomized to receive IV nitrite will receive the lowest dose (1 mg) of IV nitrite and compared to one placebo treated patient. If there is no significant decrease in blood pressure or elevation in heart rate, we will then dose escalate to the 6 mg dose in 4 patients and placebo in two patients. Dose escalation to the highest (14 mg) dose will again be contingent on the absence of significant hypotension or tachycardia in the drug treated patients compared to the pooled (n=3) placebo treated patients. The final block of patients will be randomized to the high nitrite dose (n=4) or placebo (n=2). Final comparisons of all groups will be made to the pooled (n=5) placebo group