Key Points
- To compare the relative effects of sodium nitroprusside and nitroglycerin on electrocardiographic ischemic injury and myocardial perfusion during acute myocardial infarction.
- Measured ST-segment elevation in 10 patients with anterior acute myocardial infarction treated with intravenous sodium nitroprusside (mean 95 µg/min) and sublingual nitroglycerin (mean 0.48 mg).
- Evaluated epicardial electrograms and regional myocardial blood flow using microsphere techniques during coronary artery occlusion in 14 open-chest dogs under nitroprusside and nitroglycerin administration.
- In patients, sodium nitroprusside increased ST-segment elevation by 2.0 ± 0.2 mm, whereas nitroglycerin reduced ST-segment elevation by 1.4 ± 0.4 mm.
- In dogs, nitroprusside worsened ST-segment elevation from 4.6 ± 0.6 to 5.7 ± 0.6 mV (P < 0.05) and reduced ischemic zone blood flow from 35 ± 3 to 27 ± 2 ml/min/100 g (P < 0.01).
- In dogs, nitroglycerin decreased ST elevation from 4.9 ± 0.7 to 3.0 ± 0.7 mV (P < 0.05), increased ischemic blood flow to 43 ± 4 ml/min/100 g (P < 0.05), and raised the endo/epicardial flow ratio from 0.57 ± 0.06 to 0.69 ± 0.07 (P < 0.01).
Structured PICO
Does nitroglycerin compared to nitroprusside improve electrocardiographic ischemic injury and regional myocardial blood flow in acute myocardial infarction?
PPopulation10 patients with anterior acute myocardial infarction and ST-segment elevation stable for 60 min, and 14 open-chest dogs with coronary artery occlusions.
IInterventionNitroglycerin (average 0.48 mg sublingually)
CComparatorSodium nitroprusside (average 95 mug/min i.v.)
OOutcomeElectrocardiographic ischemic injury (ST-segment elevation) and regional myocardial blood flow (RMBF)surrogate
Nitroglycerin reduces electrocardiographic ischemic injury by increasing perfusion to ischemic areas, whereas nitroprusside increases ischemic injury by reducing perfusion, making nitroglycerin preferable in early acute myocardial infarction.