[Use of isosorbide dinitrate (Risordan) injection in left ventricular failure following acute myocardial infarction...

Haemodynamic and echocardiographic studies of isosorbide dinitrate were conducted in 12 patients (8 men and 4 women) with left ventricular failure consecutive to recent myocardial infarction. The groups: group I received 5 mg/h and group II 10 mg/h Risordan intravenously. After one hour treatment, group I patients showed a significant fall in both PAP (from 32.3 +/- 5.3 to 26.7 +/- 6.9 mmHg; p less than 0.01) and PCP (from 21.8 +/- 4.7 to 17.3 +/- 7.7 mmHg; p less than 0.05). These haemodynamic changes were amplified after a second hour of treatment: PAP fell to 24 +/- 7.9 mmHg (p less than 0.01) and PCP to 14.2 +/- 4.4 mmHg (p less than 0.001). RAP decreased from 7.2 +/- 5.1 to 3.5 +/- 5 (p less than 0.05). There were no changes in heart rate, systemic arterial pressure, peripheral resistance, cardiac index, forward stroke work nor, on echocardiography, in ventricular diameters, shortening fraction and VCF. After one hour treatment, group II patients showed a fall in PAP (from 30.5 +/- 4.7 to 21.7 +/- 3.5 mmHg; p less than 0.01), PCP (from 21.7 +/- 4.8 to 14.8 +/- 4.9 mmHg: p less than 0.001) and RAP (from 10.3 +/- 2.9 to 7.2 +/- 2; p less than 0.01). The systolic diameter of the left ventricle was reduced from 66.3 +/- 10.6 to 64.3 +/- 11.3 (p less than 0.01). After 4 hours, improvement in PAP and PCP was maintained; the other values remained stable. The effectiveness of Risordan i.v. in left ventricular failure consecutive to acute myocardial infarction is due to reduction of filling pressures in the left ventricule. With the 10 mg/h dose, as opposed to the 5 mg/h dose, the systemic arterial pressure and the double and triple products tend to be reduced, which suggests greater effectiveness.