title: Selective pulmonary vasodilation improves ventriculovascular coupling and gas exchange in a patient with unrepaired single-ventricle physiology.
abstract: We describe a 63-year-old patient with unrepaired tricuspid valve atresia and a hypoplastic right ventricle (single-ventricle physiology) who presented with progressive symptomatic hypoxia. Her anatomy resulted in parallel pulmonary and systemic circulations, pulmonary arterial hypertension, and uncoupling of the ventricle/pulmonary artery. Hemodynamic and coupling data were obtained before and after pulmonary vasoactive treatment, first inhaled nitric oxide and later inhaled treprostinil. The coupling ratio (ratio of ventricular to vascular elastance) shunt fractions and dead space ventilation were calculated before and after treatment. Treatment resulted in improvement of the coupling ratio between the ventricle and the vasculature with optimization of stroke work, equalization of pulmonary and systolic flows, a decrease in dead space ventilation from 75% to 55%, and a significant increase in 6-minute walk distance and improved hypoxia. Inhaled treprostinil significantly increased 6-minute walk distance and improved hypoxia. This is the first report to show that pulmonary vasoactive treatment can be used in a patient with unrepaired single-ventricle anatomy and describes the hemodynamic effects of inhaled therapy on ventriculovascular coupling and gas exchange in the pulmonary circulation in this unique physiology.
authors.affiliation: Department of Pulmonary, Critical Care, Sleep, and Allergy Medicine, University of Arizona, Tucson, Arizona, USA.
authors.forename: F
authors.initials: F
authors.lastname: Rischard
authors.affiliation: Pulmonary Vascular Disease Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: R
authors.initials: R
authors.lastname: Vanderpool
authors.affiliation: BIO5 Institute, University of Arizona, Tucson, Arizona, USA.
authors.forename: I
authors.initials: I
authors.lastname: Jenkins
authors.affiliation: Department of Pulmonary, Critical Care, Sleep, and Allergy Medicine, University of Arizona, Tucson, Arizona, USA.
authors.forename: M
authors.initials: M
authors.lastname: Dalabih
authors.affiliation: Department of Pediatrics, University of Arizona, Tucson, Arizona, USA.
authors.forename: J
authors.initials: J
authors.lastname: Colombo
authors.affiliation: Department of Pediatrics, University of Arizona, Tucson, Arizona, USA.
authors.forename: D
authors.initials: D
authors.lastname: Lax
authors.affiliation: Department of Pediatrics, University of Arizona, Tucson, Arizona, USA.
authors.forename: M
authors.initials: M
authors.lastname: Seckeler
keywords: congenital heart disease; pulmonary hypertension; treatment effect; ventricular/vascular coupling hemodynamics