Bolus i.v. nitroglycerin treatment of ischemic chest pain in the ED

A prospective case series was conducted to demonstrate the safety and efficacy of intravenous nitroglycerin (i.v. NTG) boluses in the treatment of ischemic chest pain (CP) in the emergency department (ED). Patients with CP symptomatic after sublingual nitroglycerin (SL NTG) therapy with a systolic blood pressure (SBP) greater than 95 mmHg were included. Patients were treated with i.v. NTG boluses of 0.05 mg to 0.4 mg during a 1- to 2-minute period per a protocol based on the patient's prebolus SBP. This was followed by a maintenance infusion. Additional NTG boluses were repeated every 5 minutes as needed. The end point of treatment was the resolution of chest discomfort, thrombolysis, or a SBP less than 95 mmHg. There were 16 cases of CP. All 16 patients treated, ie, 5 with acute myocardial infarction and 11 with unstable angina showed significant decrease in chest discomfort after 1 to 2 boluses. Two of five with acute myocardial infarction and 9 of 11 patients with unstable angina had complete relief of chest pain after 1 to 4 boluses. There were no episodes of hypotension (SBP < 90 mmHg) in any of the 16 cases. The judicious use of i.v. NTG boluses administered during a 1- to 2-minute period, in the ED, appears safe and efficacious in patients with CP unresponsive to SL NTG therapy.