Nav: Home

The pressure difference and vortex flow of blood in the heart chambers may signal heart dysfunction

June 21, 2019

Japanese scientists at Tokyo University of Agriculture and Technology (TUAT), Teikyo University of Science, and Juntendo University have found -- in animal studies -- a close relationship between vortex flow and pressure differences in the ventricles, or lower chambers, of the heart. The new information could inform the development of new markers for cardiovascular dysfunction that can lead to heart failure.

Their findings were published on April, 2019 in the American Journal of Physiology-Heart and Circulatory Physiology.

Every beat of the heart consists of two stages. In the first stage, known as diastole, the left and right lower chambers of the heart (called ventricles) relax and expand, and blood flows into them from the left and right upper chambers (called atrium). Once the ventricles are full of blood, the second stage, known as systole, is triggered. The muscles in the ventricle walls contract and blood is pumped from the left ventricle to the aorta (main artery carrying oxygenated blood to the body), and from the right ventricle to the pulmonary artery (carrying deoxygenated blood back to the lungs).

Diastolic dysfunction is a common heart condition in both domestic animals and humans, particularly among the elderly, where the diastole stage does not function as efficiently as it should. The muscles in the ventricle walls become thickened and stiff, losing their elasticity, and do not relax and expand properly. As a result, the capacity of these chambers to fill up with blood is reduced. This in turn causes blood to accumulate in other areas of the body.

The restriction in flow causes pressure inside the ventricles to build up as blood pumped with the next heartbeat tries to enter the chamber which, due to its inability to expand properly, lacks sufficient capacity to accommodate it all. Diastolic dysfunction is characterized by an increased pressure in the left ventricle as the oxygenated blood returning from the lungs tries to enter. As the surplus blood has to go somewhere, it also causes blood and pressure to build up in the blood vessels around the lungs (pulmonary congestion) or in the vessels returning blood back to the heart (systemic congestion).

In the case of pulmonary congestion, fluid can leak through the vessel membranes into the alveoli (tiny air sacs that allows air exchange) in the lungs, resulting in pulmonary edema -- a condition where oxygenation of the blood is impaired, leading to breathing difficulties and, in severe cases, to potentially fatal diastolic heart failure.

As blood flows from the left atrium into the left ventricle, it forms a swirling mass of fluid known as a vortex ring. In terms of its fluid dynamics, a rotating vortex is believed to flow more efficiently than a straight, steady flow of fluid and therefore assists filling of the left ventricle during diastole. A healthy heart that exerts sufficient suction force typically has a large intraventricular pressure difference, whereas a heart with diastolic dysfunction has a low intraventricular pressure difference.

Previous studies have suggested that diastolic vorticity, or fluid dynamics of the blood in the ventricle, can be used as an indicator of diastolic function. However, the link between intraventricular pressure difference and diastolic vorticity is unclear. It is thought that pressure differences within the ventricles is linked to the formation of vortexes, and that vortex flow could be used as a measure of ventricular relaxation that is associated with heart failure.

For this study, the researchers monitored six healthy anesthetized dogs to determine whether intraventricular fluid dynamics can be assessed clinically using non-invasive imaging techniques, and whether impaired fluid dynamics may be a source of diastolic dysfunction that can lead to heart failure.

"We showed the close relationship of vortex and intraventricular pressure difference and showed that both of them can become new markers of the left ventricular relaxation property," said Ryou Tanaka, Associate Professor in the Department of Veterinary Surgery, Faculty of Veterinary Medicine, TUAT, and co-author of the paper.

Now that the researchers have assessed the relationship between intraventricular pressure differences and vortex flow in healthy canines, their next step is to evaluate intraventricular fluid dynamics in feline cases. According to the authors, these findings suggest that further studies using these indicators on diseased subjects is warranted.
-end-
About Tokyo University of Agriculture and Technology (TUAT)

TUAT is a distinguished university in Japan dedicated to science and technology. TUAT focuses on agriculture and engineering that form the foundation of industry, and promotes education and research fields that incorporate them. Boasting a history of over 140 years since our founding in 1874, TUAT continues to boldly take on new challenges and steadily promote fields. With high ethics, TUAT fulfills social responsibility in the capacity of transmitting science and technology information towards the construction of a sustainable society where both human beings and nature can thrive in a symbiotic relationship. For more information, please visit http://www.tuat.ac.jp/en/.

Original publication:

Left ventricular vortex and intraventricular pressure difference in dogs under various loading conditions.
Matsuura K, Shiraishi K, Sato K, Shimada K, Goya S, Uemura A, Ifuku M, Iso T, Takahashi K, Tanaka R.
Am J Physiol Heart Circ Physiol. 2019 Apr 1;316(4):H882-H888
doi: 10.1152/ajpheart.00686.2018

Contact:

Ryou Tanaka, DVM, PhD
Associate Professor,
Department of Veterinary Surgery, Animal Medical Center
Tokyo University of Agriculture and Technology.
Email: fu0253@go.tuat.ac.jp

Tokyo University of Agriculture and Technology

Related Relationship Articles:

Fungal diversity and its relationship to the future of forests
Stanford researchers predict that climate change will reduce the diversity of symbiotic fungi that help trees grow.
Evolution: Revelatory relationship
A new study of the ecology of an enigmatic group of novel unicellular organisms by scientists from Ludwig-Maximilians-Universitaet (LMU) in Munich supports the idea hydrogen played an important role in the evolution of Eukaryota, the first nucleated cells.
Symbiosis as a tripartite relationship
While viruses are typically known for their pathogenic properties, new research findings now also demonstrate a positive influence of bacteriophages on the interaction of host organisms with bacteria.
Timing is everything for the mutualistic relationship between ants and acacias
Ant-acacia plants attract ants by offering specialized food and hollow thorns in which the ants live, while the ant colony in turn defends its acacia against herbivores.
Foodie calls: Dating for a free meal (rather than a relationship)
New psychology research reveals 23-33% of women in an online study say they've engaged in a 'foodie call,' where they set up a date for a free meal.
Combing through someone's phone could lead to end of relationship -- or not
For some people, the thought of their partner, friend or colleague snooping through their phone, reading their texts and emails, is an automatic deal breaker.
How a new father views his relationship with his partner
A new father's views on his changing relationship with his wife or partner may depend in part on how much support he feels from her when he is caring for their baby, a new study suggests.
Understanding relationship break-ups to protect the reef
Unravelling the secrets of the relationship between coral and the algae living inside it will help prevent coral bleaching, University of Queensland researchers believe.
More than one in 10 Canadians want to be in an open relationship
A sizeable number of Canadian adults are either in or would like to be in an open relationship, suggests new research from the University of British Columbia.
Who should Fido fear? Depends on relationship
As states around the country move to stiffen punishments for animal cruelty, Michigan State University researchers have found a correlation between the types of animal abuse committed and the perpetrator's relationship to an animal and its owner.
More Relationship News and Relationship Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.