Right ventricular size is acutely decreased by inhaled nitric oxide in newborns with pulmonary hypertension.
The pressure and volume demands of the right and left ventricles may dramatically change following selective pulmonary vasodilation in newborns with pulmonary hypertension. Thus, ventricular planimetry was performed by two-dimensional echocardiography in 35 newborns with lung disease and increased pulmonary vascular resistance who were treated with inhaled nitric oxide to determine the influence of therapy on right and left ventricular size and function. The end-diastolic and end-systolic areas of each ventricle were measured from apical 4-chamber images before, and 30 to 60 minutes after, the onset of 20 parts per million inhaled nitric oxide. Estimates of ventricular function were determined by the systolic decrease in ventricular area, (diastolic area - systolic area) x 100/diastolic area. Heart rate, systemic blood pressure, and left ventricular areas did not change. However, the oxygenation index, the proportion of right-to-left ductal shunt (nonrestrictive ductus arteriosus, n = 22), the systolic pulmonary arterial pressure (closed or restrictive ductus arteriosus, n = 13), and the right ventricular diastolic and systolic areas were decreased after nitric oxide inhalation. The baseline systolic decrease in left ventricular area was lower in a subgroup of patients who developed an increase in left ventricular diastolic area following nitric oxide inhalation. Thus, nitric oxide improves pulmonary hemodynamics and decreases right ventricular size in newborns with lung disease and pulmonary hypertension. However, newborns may develop an increase in left ventricular size if left ventricular function is decreased prior to therapy.
Division of Pediatric Cardiology, University of Utah, Salt Lake City, USA.
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D000280:Administration, Inhalation; D015986:Confounding Factors, Epidemiologic; D004452:Echocardiography; D005260:Female; D005865:Gestational Age; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000188:drug therapy*; D007231:Infant, Newborn; D008297:Male; D009569:Nitric Oxide / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000627:therapeutic use*; D016277:Ventricular Function, Left / Q000187:drug effects*; D016278:Ventricular Function, Right / Q000187:drug effects*
D014665:Vasodilator Agents; D009569:Nitric Oxide