Hemodynamic and Inotropic Effects of Nitric Oxide in Pulmonary Hypertension

• Published in: The Journal of surgical research 1997-05, Vol.69 (2), p.288-294
• Main Authors: Chen, Edward P., Bittner, Hartmuth B., Davis, R.Duane, Van Trigt, Peter
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Body Weight; Cardiology. Vascular system; Disease Models, Animal; Dogs; Heart; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Hemodynamics - drug effects; Hypertension, Pulmonary - physiopathology; Medical sciences; Monocrotaline - analogs & derivatives; Myocardial Contraction - drug effects; Nitric Oxide - pharmacology; Pneumology; Pulmonary Circulation - drug effects; Pulmonary hypertension. Acute cor pulmonale. Pulmonary embolism. Pulmonary vascular diseases; Regional Blood Flow - drug effects; Vascular Resistance - drug effects
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1006/jsre.1997.5031

Right ventricular failure following cardiac transplantation is most commonly related to pre-existent recipient pulmonary hypertension secondary to chronic congestive heart failure. Although nitric oxide has had some role clinically in improving pulmonary hemodynamics and right ventricular function in this setting, an appropriate large-animal model of stable pulmonary hypertension has not been available for basic investigation of this problem. This study was designed to examine the hemodynamic and inotropic effects of inhaled nitric oxide using a canine model of monocrotaline pyrrole-induced chronic pulmonary hypertension. Eight mongrel dogs (22–25 kg) were used. All animals underwent percutaneous pulmonary artery catheterization to measure right heart hemodynamics prior to and 8 weeks after a right atrial injection of monocrotaline pyrrole. Eight weeks post-injection, all hearts were instrumented with a pulmonary artery flow probe, sonomicrometric dimension transducers, and micromanometers. Data were collected at baseline and following nitric oxide administration. Eight weeks post-monocrotaline pyrrole injection, significant increases were observed in the pulmonary hemodynamics compared to pre-injection. Nitric oxide led to significant decreases in pulmonary vascular impedance. Significant improvements in pulmonary blood flow, transpulmonary efficiency, and right ventricular contractility were also observed. This investigation demonstrates the well-known clinical effects of nitric oxide in improving pulmonary hemodynamics which were also associated with an increase in pulmonary blood flow, transpulmonary efficiency, and right ventricular contractility in the setting of monocrotaline pyrrole-induced pulmonary hypertension.