ST changes during sodium nitroprusside therapy in acute myocardial infarction

Nineteen patients with acute anterior myocardial infarction who were hypertensive (systolic BP greater than or equal to 170 mm Hg and/or diastolic BP greater than or equal to 100 mm Hg) at the time of admission were treated with continuous infusion of sodium nitroprusside (NP). The administration of NP resulted in a significant elevation of ST segments probably related to decreased diastolic BP and increased HR; direct NP effects on coronary circulation cannot be excluded. These changes may indicate a negative effect on the ischemic portion(s) of the myocardium.