Navigation Links
Cold air chills heart's oxygen supply
Date:2/28/2012

People with heart disease may not be able to compensate for their bodies' higher demand for oxygen when inhaling cold air, according to Penn State researchers, making snow shoveling and other activities dangerous for some.

"This study can help us understand why cold air is such a trigger for coronary events," said Lawrence I. Sinoway, Distinguished Professor of Medicine and director of the Heart and Vascular Institute, Penn State College of Medicine.

Breathing cold air during exercise can cause uneven oxygen distribution throughout the heart. But a healthy body generally corrects for this problem and redistributes blood flow, making sure the heart continues to function properly. In people with heart problems -- such as coronary artery disease -- this may not be the case, said Sinoway.

"If you are doing some type of isometric work and you're breathing cold air, your heart is doing more work -- it's consuming more oxygen," said Sinoway, also director of the Clinical and Translational Science Institute at Penn State.

Isometric work includes such activities as shoveling snow and carrying a briefcase or laptop bag. The heart works harder when exerted in cold temperatures and the number of deaths due to cardiac arrest peaks during the winter.

"There are two different things going on here -- demand and supply," said Matthew D. Muller, postdoctoral fellow at the Heart and Vascular Institute, Penn State College of Medicine. "We thought that oxygen demand in the heart would be higher with cold-air breathing and we also thought that oxygen supply would be a little bit impaired. And that's generally what we found."

Sinoway, Muller and colleagues reported their results in a recent issue of the Journal of Applied Physiology and in the current issue of the American Journal of Physiology, Heart and Circulatory Physiology.

The researchers first studied healthy young adults in their 20s and then studied a group of healthy older adults in their 60s so that they could learn how the heart functions in people without disease. Each subject was monitored for lung function and heart functions during the trials.

In order to measure heart function during exercise, the participants performed an isometric, or static, handgrip, which is a maneuver known to increase blood pressure. Subjects squeezed the handgrip device and held it still for two minutes, providing a consistent workload on the heart for the researchers to measure. Muller and Sinoway found that there was a supply-demand mismatch in the left ventricle -- where the heart receives oxygenated blood -- yet the heart was able to continue functioning appropriately.

These findings "suggest that healthy humans can adequately redistribute blood to the subendocardium (the blood vessels entering the heart) during the combined stimulus of cold-air inhalation and handgrip exercise," the researchers stated.


'/>"/>

Contact: Victoria M. Indivero
vmi1@psu.edu
814-865-9481
Penn State
Source:Eurekalert

Related medicine news :

1. “Hearts and Minds” Education Program Launched: On Average, People with Mental illness Live 25 Years Less than Other Americans
2. Hearts of Hospice Patients Being Needlessly Shocked
3. Healing Wounds and Hearts: Warrior Weekend Helps Soldiers and Marines Relax and Recover
4. Researchers discover chemical that may protect hearts of muscular dystrophy patients
5. Hearts and Minds Promotes Wellness; African Americans Living with Mental Illness Have Higher Risk for Other Illnesses.
6. Tiny Fish Might Help Humans Fix Damaged Hearts
7. Mans Best Friend Helps Mend Broken Hearts
8. Stem cells from surgery leftovers could repair damaged hearts
9. High-Stress Jobs Tax Womens Hearts, Too
10. 2 BigHearts Board Announces Addition to Board of Directors: Michael Unetich
11. Hostile, Competitive Types May Be Harming Their Hearts
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 26, 2016 , ... Pixel Film Studios Released ProSlice Levels, ... editors can give their videos a whole new perspective by using the title ... Pixel Film Studios. , ProSlice Levels contains over 30 Different presets to choose ...
(Date:6/25/2016)... ... June 25, 2016 , ... Experts from the ... AcademyHealth’s Annual Research Meeting June 26-28, 2016, at the Hynes Convention Center in ... topics including advance care planning, healthcare costs and patient and family engagement. , ...
(Date:6/25/2016)... ... ... First Choice Emergency Room , the largest network of independent freestanding emergency ... its new Mesquite-Samuell Farm facility. , “We are pleased to announce Dr. Ogunleye ... M. Muzzarelli, Executive Medical Director of First Choice Emergency Room. , Dr. Ogunleye ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... Conventional wisdom ... of success. In terms of the latter, setting the bar too high can result ... more than just slow progress toward their goal. , Research from PsychTests.com ...
(Date:6/24/2016)... ... June 24, 2016 , ... Marcy was in a crisis. Her son James, eight, was out ... family verbally and physically. , “When something upset him, he couldn’t control his emotions,” remembers ... would throw rocks at my other children and say he was going to kill them. ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical ... the "Company"), which develops, markets and sells medical devices ... , signed a strategic cooperation agreement with Hongyuan ... "Hongyuan Supply Chain") on June 20, 2016, to develop ... the strategic cooperation agreement, Dehaier will leverage Hongyuan Supply ...
(Date:6/24/2016)... , June 24, 2016 According ... by Type (Standard Pen Needles, Safety Pen Needles), Needle ... GLP-1, Growth Hormone), Mode of Purchase (Retail, Non-Retail) - ... This report studies the market for the forecast period ... reach USD 2.81 Billion by 2021 from USD 1.65 ...
(Date:6/24/2016)... Tenn. , June 24, 2016  Arkis ... providing less invasive and more durable cerebrospinal fluid ... in funding.  The Series-A funding is led by ... Lighthouse Fund, and other private investors.  Arkis, new ... neurosurgical instrumentation and the market release of its ...
Breaking Medicine Technology: