The effect of low-dose intravenous nitroglycerin on pulmonary hypertension immediately after replacement of a stenotic mitral valve.
The postoperative effect of infusion of nitroglycerin on pulmonary vasomotor dynamics was studied in 28 patients undergoing valve replacement for mitral valve stenosis. A 30% reduction in mean pulmonary arterial pressure (38.74 +/- 8.3 to 26.92 +/- 7.72 mm Hg, p less than .001) and a 48.4% reduction in pulmonary vascular resistance index (12.08 +/- 4.19 to 5.61 +/- 1.61 U/m2, p less than .001) were observed after nitroglycerin. While pulmonary driving pressure (mean pulmonary arterial pressure minus left atrial pressure) dropped by 50.8%, cardiac and stroke volume indexes increased by 25.5% and 24.2%, respectively. The ratio pulmonary/systemic vascular resistance decreased from 34.14% to 20.9% (p less than .001). There were no significant changes in mean systemic arterial pressure (86.89 +/- 13.5 to 83.5 +/- 9.3 mm Hg, p = NS) or heart rate (97.43 +/- 20.45 to 99.36 +/- 20.9 beats/min, p = NS); left and right atrial pressures decreased by 19.5% and 9.5%, respectively. Systemic vascular resistance index decreased by 18.8%. We conclude that low-dose infusion of nitroglycerin reduces the pulmonary vascular resistance in patients with pulmonary hypertension, and consequently results in improvement in immediate postoperative hemodynamics after replacement of a stenotic mitral valve.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000150:complications / Q000601:surgery*; D005996:Nitroglycerin / Q000008:administration & dosage*; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D005996:Nitroglycerin