for people ages 1-21 (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Hythem Nawaytou, MD



The right ventricular (RV) systolic function is a key determinant of outcome in patients with pulmonary hypertension and elevated pulmonary vascular resistance. As the pulmonary artery pressure and vascular resistance increase (i.e. RV afterload) in these patients, so does the right ventricular contractility in an attempt to maintain cardiac output. This is response of a ventricle to its afterload is termed ventriculo-arterial (VA) coupling. However, there is a limit to this increase in contractility after which VA uncoupling occurs ultimately leading to decrease cardiac output and right ventricular failure. The accepted gold standard for measurement of VA coupling is the ratio of the end systolic ventricular elastance (Ees) to the end systolic arterial elastance (Ea) measured invasively via high fidelity conductance catheters during cardiac catheterization. In this study, the aim is to devise a non-invasive scoring system that can identify VA uncoupling in patients with elevated pulmonary vascular resistance using echocardiography, cardiac MRI, cardiopulmonary exercise testing and brain natriuretic peptide levels. The hypothesis is that a group of morphologic and functional variables obtained noninvasively can differentiate an RV with VA coupling from that with VA uncoupling.

Official Title

Non-Invasive Evaluation of Right Ventricular - Pulmonary Arterial Coupling in Children With Elevated Pulmonary Vascular Resistance


Pulmonary Vascular Resistance Abnormality, pulmonary vascular resistance, pediatric, VA uncoupling, Congenital Abnormalities, Measuring VA Coupling


You can join if…

Open to people ages 1-21

  • Children 1-21 years of age
  • Patients referred for cardiac catheterization for hemodynamic evaluation due to concern for pulmonary hypertension
  • Structurally normal heart

You CAN'T join if...

  • Pulmonary hypertension secondary to pulmonary venous hypertension defined as pulmonary capillary wedge pressure of more than or equal to 15mmHg
  • Pulmonary hypertension secondary to mixed pulmonary arterial and venous hypertension
  • Patient will be excluded from performing an MRI if they have:

claustrophobia, metal implants or allergy to contrast

  • Patients will be excluded from performing a cardiopulmonary exercise test (CPET) if they are: 1) less than 8 years or 2) unable to follow instructions to run on a treadmill.


  • Pediatric Pulmonary Hypertension Program accepting new patients
    San Francisco California 94143 United States
  • University of Minnesota accepting new patients
    Minneapolis Minnesota 55455 United States

Lead Scientist at UCSF

  • Hythem Nawaytou, MD
    Dr. Hythem Nawaytou is a cardiologist who cares for children with pulmonary hypertension in the hospital as well as the clinic. He performs and interprets all types of echocardiography (ultrasound of the heart), including fetal echocardiograms (used to help diagnose and evaluate many heart conditions before birth).


accepting new patients
Start Date
Completion Date
Hythem Nawaytou
Study Type
Expecting 65 study participants
Last Updated