Controlled study of the haemodynamic effects of isosorbide 5-mononitrate in acute myocardial infarction

In view of the favourable results of the short-term therapy of acute myocardial infarction (AMI) with glyceryl-trinitrate (GTN) infusion, we undertook a randomized study to test the hypothesis whether the administration of a single dose of isosorbide 5-mononitrate (IS 5-MN) given orally would have the same favourable haemodynamic effect as observed with GTN infusion. For this purpose we evaluated the haemodynamic effects of IS 5-MN compared to isosorbide dinitrate (ISDN), observed in the same group of patients. 10 patients (8 males, 2 females) aged 50-76 years (mean 63) with AMI (7 anterior, 3 inferior) admitted to the coronary care unit within 48 h from onset of symptoms were entered into this single-blind randomized study; at the time of study entry, 8 patients were in Killip class I, and 2 patients in Killip class II. All drugs with haemodynamic effects were withdrawn 12 h before the study started. Both the haemodynamic profile and the clinical status were stable in all patients. Haemodynamic parameters were recorded with a Swan-Ganz thermodilution catheter, cardiac output was measured by the thermodilution method, and the left ventricular ejection time was calculated according to the Weissler method. The echo left ventricular end-diastolic diameter was measured by evaluation of the M-mode echocardiographic recording.(ABSTRACT TRUNCATED AT 250 WORDS)