Heart-stopping drugs

A NEW way of stopping the heart during bypass operations could reduce damage to the heart and improve patients' chances of a full recovery.

More than a million people a year have open-heart surgery to unblockor bypass clogged arteries, or repair damaged valves. The heart is usually stopped for about one hour while they are under the knife because it is impossible to operate on a moving target. But the standard method of achieving this- flooding the heart with potassium ions- can cause permanent damage.

Now Geoffrey Dobson and Michael Jones of James Cook University in Townsville, Australia, have developed an alternative. It has only been tested on animals so far, but experts say the results, due to appear in the Journal of Thoracic and Cardiovascular Surgery, look promising. "By keeping potassium levels normal they are preventing injuries to the muscle cells and to the vessels that carry blood to the heart," says Peter Macdonald, a cardiologist at St Vincent's Hospital in Sydney.

In resting muscle cells, the distribution of ions across the cell membrane generates an electric potential. The waves of electrical activity that sweep across the heart, telling muscle cells to contract, are generated when channels in the membrane open, allowing ions to flow across the membrane and depolarise the cells. Flooding the heart with potassium ions freezes its cells in this depolarised state.

Dobson and Jones instead freeze the heart in the resting state using two drugs: adenosine, which opens some of the channels that transport potassium ions in and out of the cell, and lignocaine (known as lidocainein the US), which blocks sodium ion channels.

"There are two ways to stop a heart cell. Let it run out of gas- that's the potassium infusion-or to not even turn it on. That's what Dobson has done," says Jakob Vinten-Johansen, a cardiovascular physiologist at Emory University in Atlanta, Georgia, who now collaborates with Dobson.


Contact: Claire Bowles
New Scientist

Page: 1 2 3

Related medicine news :

1. UW research shows risk factors for relapse among health care professionals who abuse drugs
2. New studies show mixed results on epilepsy drugs and birth defects
3. Newly discovered pathway might help in design of cancer drugs
4. Study examines consequences of Thailands war on drugs
5. Computational tool predicts how drugs work in cells, advancing efforts to design better medicines
6. Three anti-platelet drugs used in combination are safe
7. HIV patients may be at risk of heart problems when taking protease inhibitor drugs
8. Clot-busting drugs may help detect potentially deadly leg clots
9. Herb used to treat diabetes works like modern-day prescription drugs, study suggests
10. Penn study shows how next-generation diabetic drugs could work more selectively
11. Study shows drugs such as Vioxx and Celebrex were widely over-used long before recent problems

Post Your Comments:

(Date:6/26/2016)... Clarkston, Michigan (PRWEB) , ... June 26, 2016 ... ... respect to fertility once they have been diagnosed with endometriosis. These women need ... but they also require a comprehensive approach that can help for preservation of ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX ... Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over ... Cut Pro X . Simply select a ProHand generator and drag it above media ...
(Date:6/25/2016)... ... , ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department ... in recognition of their exemplary accomplishments in worksite health promotion. , The Wellness at ... Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one of 42 ...
(Date:6/24/2016)... ... ... June 19, 2016 is World Sickle Cell Observance Day. In an effort ... holistic treatments, Serenity Recovery Center of Marne, Michigan, has issued a pain ... Disease (SCD) is a disorder of the red blood cells, which can cause episodes ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... ... now offering micro-osteoperforation for accelerated orthodontic treatment. Dr. Cheng has extensive experience with ... Damon brackets , AcceleDent, and accelerated osteogenic orthodontics. , Micro-osteoperforation is a ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... -- The Academy of Managed Care Pharmacy (AMCP) today ... allow biopharmaceutical companies to more easily share health care ... coverage decisions, a move that addresses the growing need ... The recommendations address restrictions in the sharing of product ... a prohibition that hinders decision makers from accessing HCEI ...
(Date:6/24/2016)... --  Pulmatrix, Inc ., (NASDAQ: PULM ), ... today that it was added to the Russell Microcap ... set of U.S. and global equity indexes on June ... for Pulmatrix," said Chief Executive Officer Robert Clarke ... in developing drugs for crucial unmet medical needs, and ...
(Date:6/23/2016)... Calif. , June 23, 2016 Any dentist ... many challenges of the current process. Many of them do ... of the technical difficulties and high laboratory costs involved. And ... to offer it at such a high cost that the ... it. Dr. Parsa Zadeh , founder of ...
Breaking Medicine Technology:
Cached News: