Nav: Home

New insights into exercise right ventricular pressure may help define a new 'normal'

June 21, 2017

In individuals with structurally normal hearts, systolic pressure is assumed to be equal in the lung arteries and the part of the heart pumping to them. A difference in pressure between the right ventricle (RV) and pulmonary artery (PA) suggests an obstruction to blood flow (specifically in the right ventricular outflow tract, or RVOT), which is most often seen in patients who have congenital heart defects or sometimes after cardiac surgery or lung transplantation. An RVOT pressure gradient is usually seen as a sign for concern: if the obstruction to the blood flow is severe, it can lead to right heart failure.

However, investigators at Brigham and Women's Hospital (BWH) recently reported an unexpected observation among patients experiencing unexplained shortness of breath. Their findings, reported in PLOS ONE, suggest that the RV-PA pressure difference may not always be a reflection of disease, but rather, may be a normal physiological response to exercise.

The research team observed that when patients underwent cardiopulmonary exercise testing, a subset of them (who had normal resting RV-PA pressure) developed the pressure gradient during high levels of upright exercise when the heart was squeezing. In a retrospective study, the investigators reviewed data from patients referred to the BWH Dyspnea Center who underwent an invasive, comprehensive exercise test with a catheter in place to measure RV and PA pressures. Their body's response was measured through heart catheterization when the patients were resting supine (lying down), but also when they were in an upright position, exercising on a stationary bike until their ability to keep exercising was limited by symptoms. Usually, patients are only tested in the supine position at rest; testing upright patients provided new information about when and in which patients an RVOT pressure gradient may occur.

Surprisingly, those in the study who developed the RVOT pressure gradient during high levels of upright exercise were not more limited. Rather, they tended to be the younger patients with better exercise capacity.

"Our work suggests that, surprisingly, this pressure gradient during exercise may represent a normal, physiologic state in fit, young people," said corresponding author Alexander Opotowsky, MD, MPH of the Pulmonary Vascular Disease Team and the Dyspnea Center at BWH and of Boston Adult Congenital Heart Service, a joint program of Boston Children's Hospital and BWH.

Due to the scope of this study, additional testing among asymptomatic, young, aerobically fit individuals will need to be conducted in order to confirm the suggestive findings and better understand the RVOT gradient. The reasoning behind why an RVOT gradient would form during upright exercise currently remains unclear and further studies to illuminate the mechanism responsible for the observed RVOT gradient are needed. But importantly, the results of this study may have implications for the standard practice of exercise echocardiography.

"Currently, some of our testing with echocardiography depends on the fact that the RV and PA have the same pressure," said Opotowsky. "Our findings raise important questions about this assumption and may have implications for how echocardiography is used to estimate systolic pulmonary artery pressure during exercise."
-end-
Paper cited: van Riel AC et al. "Hemodynamic and metabolic characteristics associated with development of a right ventricular outflow tract pressure gradient during upright exercise" PLOS ONE DOI: 10.1371/journal.pone.0179053

Brigham and Women's Hospital

Related Blood Flow Articles:

Blood flow monitor could save lives
A tiny fibre-optic sensor has the potential to save lives in open heart surgery, and even during surgery on pre-term babies.
Changes in blood flow tell heart cells to regenerate
Altered blood flow resulting from heart injury switches on a communication cascade that reprograms heart cells and leads to heart regeneration in zebrafish.
Blood flow command center discovered in the brain
An international team of researchers has discovered a group of cells in the brain that may function as a 'master-controller' for the cardiovascular system, orchestrating the control of blood flow to different parts of the body.
Researchers closer to new Alzheimer's therapy with brain blood flow discovery
By discovering the culprit behind decreased blood flow in the brain of people with Alzheimer's, biomedical engineers at Cornell University have made possible promising new therapies for the disease.
In vitro grafts increase blood flow in infarcted rat hearts
Advances in stem cell research offer hope for treatments that could help patients regrow heart muscle tissue after heart attacks, a key to patients achieving more complete recoveries.
Balloon-guided catheters provide better blood flow following stroke interventions
Patients who have experienced a stroke as a result of blockages of the arteries in the brain have better outcomes with the use of balloon-guided catheter surgery as compared to having a conventional guided catheter procedure.
Scientists developed new contactless method of measuring blood flow in hands
Russian researchers proposed a new contactless method for measuring blood flow in the upper limbs.
Researchers investigate correlation between blood flow and body position
For the first time ever, an international research group detected alterations in capillary blood flow around the face caused by body position change.
Restoring blood flow may be best option to save your life and limb
Amputation for severe blockages in the lower limbs has a lower survival rate than other treatment options that restore blood flow.
Blood flow in the heart revealed in a flash
Researchers at Linköping University have for the first time been able to use information from computer tomography images to simulate the heart function of an individual patient.
More Blood Flow News and Blood Flow Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.