Nitrates in acute myocardial infarction.

Nitrates produce a more efficacious early haemodynamic profile than other drugs currently available for the treatment of patients with left ventricular failure following acute myocardial infarction. Given by intravenous infusion their venodilator activity rapidly results in a substantial reduction in the excessive left ventricular preload. Their arterial dilator effects result in a less marked but advantageous reduction in the reflex increase in left ventricular afterload. The haemodynamic consequences are a reduction in left ventricular global dysfunction, wall stress and myocardial oxygen consumption and enhanced subendocardial perfusion. These beneficial haemodynamic attributes may reduce infarct size and contribute to a reduction in the potential to develop arrhythmias. Nitrates form the first-line treatment of choice in this clinical emergency, but may be combined with advantage in some situations with diuretics and arteriolar dilators. Nitrates offer potential but less certain advantages in the prophylactic treatment of uncomplicated myocardial infarction.