Metaraminol-induced reversal of acute myocardial ischaemia associated with hypotension and refractory to intravenous nitroglycerin.

In seven patients, acute myocardial ischaemia associated with ST segment elevation (5.7 +/- 1.6 mm, mean +/- SEM) and arterial hypotension (systolic blood pressure 57 +/- 9 mmHg), was reversed within 9 min (mean time to reversal 274 +/- 45 s) by the intravenous administration of metaraminol (1.9 +/- 0.2 mg). This myocardial ischaemia was refractory to nitroglycerin and, in every patient, the increases in blood pressure induced by metaraminol (to a mean systolic blood pressure of 191 +/- 22 mmHg) preceded reversal of the ECG changes. It is suggested that, in some patients, transmural myocardial ischaemia of recent onset associated with hypotension can be reversed by transiently increasing blood pressure with metaraminol.