ScienceDaily (July 7, 2010) — Scientists at The University of Manchester have solved a mystery connected with why people die from sudden cardiac arrest during sleep — potentially saving thousands of lives.

The pioneering research, using detailed computer models, could help save lives through preventative treatment of those most at risk from a form of heart rhythm disorder called sick sinus syndrome.

This occurs when the activity of the heart’s pacemaker, the sinoatrial node, is impaired. Up to now, no-one has been able to work out why this happens.

But groundbreaking research by Professor Henggui Zhang at The University of Manchester shows how gene mutation and activity of the nervous system can combine to seriously disrupt the heart’s normal rhythm.

This research means it would be possible to identify those most at risk of suffering sudden cardiac death, which can affect people of any age but particularly the healthy elderly and well-trained athletes.

It could then be possible to control the risk by using drugs or a pacemaker.

Sudden cardiac death occurs after an abrupt loss of consciousness within one hour of the onset of acute symptoms. This often happens during the night as heart rate slows dramatically at night times.

The form of sick sinus syndrome investigated is not connected with structural heart disease, but with genetic mutations that alter a protein called SCN5A that is involved in generation of electrical activity in the heart. Problems can occur for people of any age who possess this genetic abnormality.

Every year, hundreds of thousands of people around the world die from sudden cardiac death — many of them young and fit. It is estimated that about 30% of sudden cardiac deaths occur at nighttime.

The research has been made possible by developing models of cardiac electrical activity over 13 years and has now been published in the journal Circulation Research.

Using experimental measurements from the sinoatrial node together with detailed computer models, Professor Zhang, from the University’s School of Physics and Astronomy, has been able to simulate the electrical activity in cardiac tissue.

Their research, carried out with scientists from The University of Bristol, found that there is a chemical present in the nervous system which, in healthy individuals, acts to slow the heart rate.

But in sick sinus syndrome patients, it may entirely prevent electrical activity spreading across the heart, thereby compromising cardiac function leading to heart arrest.

These effects are associated with gene mutations which can be detected by tests.

Professor Zhang said: “Previously, we did not know why some people with sick sinus syndrome would die suddenly, but now we do know why risk can increase at night during sleep. Our findings may be an important step towards ways of preventing this.

“We may have to reduce the influence of a certain form of nerve activity on the hearts of sick sinus patients. This could be via drugs or pacemaker devices.

“The computer models we have made have created the effects of the chemicals on the heart and we then tested this experimentally with results that supported the computer predictions.

“Our laboratory experiments have been building up computer models to analyse the heart for the past 13 years. We are now in a position to test other forms of sick sinus syndrome so we can hopefully identify common features that can lead us to more effective treatments”

Professor Jules Hancox from the University of Bristol, who collaborated on the study, said: “The insights into sick sinus syndrome from this study are potentially of great importance.

“If other forms of sick sinus syndrome that involve mutations to different proteins in the heart are affected by nerve activity in the same way, this may identify a common target to reduce or eliminate risk of dangerous arrhythmia.”


Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Manchester.


Journal Reference:

  1. T. D. Butters, O. V. Aslanidi, S. Inada, M. R. Boyett, J. C. Hancox, M. Lei, H. Zhang. Mechanistic Links Between Na Channel (SCN5A) Mutations and Impaired Cardiac Pacemaking in Sick Sinus Syndrome. Circulation Research, 2010; DOI: 10.1161/CIRCRESAHA.110.219949

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University of Manchester (2010, July 7). Scientists reveal the mystery of sudden cardiac death. ScienceDaily. Retrieved July 7, 2010, from http://www.sciencedaily.com­ /releases/2010/07/100706093235.htm

Medscape.com, by Laurie Barclay MD, July 6, 2010 — Less medical intervention during planned home birth is associated with a tripling of the neonatal mortality rate vs planned hospital birth, according to the results of a systematic review and meta-analysis reported online first July 1 and will appear in the September 10 print issue of the American Journal of Obstetrics & Gynecology.

“The American College of Obstetricians and Gynecologists does not support home birth, citing safety concerns and lack of rigorous scientific study,” write Joseph R. Wax, MD, from Maine Medical Center in Portland, and colleagues. “We sought to systematically review the medical literature on the maternal and newborn safety of planned home vs planned hospital birth.”

Selection criteria for the meta-analysis were English-language peer-reviewed publications from developed Western nations, in which maternal and newborn outcomes were reported by planned delivery location. The investigators calculated summary odds ratios with 95% confidence intervals for these outcomes.

Compared with planned hospital births, fewer maternal interventions were associated with planned home births, including epidural analgesia, electronic fetal heart rate monitoring, episiotomy, and operative delivery. Women who delivered at home had lower rates of lacerations, hemorrhage, and infections, and their offspring had lower rates of prematurity, low birth weight, and assisted newborn ventilation.

Perinatal mortality rates were similar for planned home and hospital births, but neonatal mortality rates were significantly higher with planned home births.

“Less medical intervention during planned home birth is associated with a tripling of the neonatal mortality rate,” the study authors write.

Limitations of this study include those inherent in the included studies, self-selection of women for home birth, and insufficient data for some outcomes.

“Future research needs to be directed at identifying contributors to and reducing the apparently excessive neonatal mortality among planned home births,” the study authors conclude. “Data regarding maternal mortality, maternal and newborn readmission rates and indications, and newborn neurologic injury are insufficient for evaluation and comparison…. Ideally, the results of such work will contribute to an obstetric and newborn best practices model benefiting women and children regardless of chosen birth location.”

The study authors have disclosed no relevant financial relationships.

Am J Obstet Gynecol. Published online July 1, 2010.

Tips for women…

Forbes.com, July 7, 2010, by Meghan Casserly  –  “Most folks are about as happy as they make up their minds to be,” Abraham Lincoln once famously said. And now it turns out that his statement was more than just a folksy quip. New research in neuroscience and psychology shows that we may be more in control of our emotions and anxiety levels than we think. And for the more than 75% of Americans who suffer from stress-related conditions, according to the American Psychiatric Association, these findings may give them new help for managing stress.

Stress comes from the way we think and react to outside stimulus, so people with anxious tendencies will react in a more fearful way than their calmer counterparts. “The reaction to stress stimuli comes from a part of the brain in the prefrontal cortex that is primitive–it’s a fight or flight reaction, ” says Don Goewy, author of Mystic Cool, a self-help book about stress management. Your brain can’t tell the difference between real and perceived danger, so stress levels jump when an individual faces a real physical threat or a perceived threat, such as being called into a supervisor’s office.

In most animals, a serious threat causes a fight-or-flight reaction, but once the danger has passed, the brain circuitry stops flaring and they return to a state of rest. Unfortunately for us, humans perceive threats of varying intensities from so many different parts of our lives–being late to work, traffic, bills–that our brains can become over stimulated by the stress cycle. For many of us, this means living in a constant state of high alert, or a state of fear.

Here’s how the science works: Our brains sense fear in a part of our brain called the amygdala. In response to fear or stress, the hypothalamus in the brain secretes corticotropin-releasing factor (CRF), which results in the pituitary gland releasing another hormone, adrenocorticotropic hormone (ACTH) activates the adrenal glands that releases the stress hormone cortisol. This hormonal feedback loop is referred to as the hypothalamic-pituitary-adrenal) axis (HPA). It is, essentially, the cycle of panic.

Dr. Robert Sapolsky of Stanford University and Dr. Robert Davidson of The University of Wisconsin-Madison are some of the neuroscientists researching stress management, and they contend that people can retrain their brains to combat stress.

The ability for the brain to create new pathways is called neuroplasticity. The brain consists of nerve cells (neurons) and glial cells that are interconnected, and when these connections are changed, either by adding or removing these connections or by adding new cells, new information is stored in the brain.

“When you learn someone’s name to the point of remembering it, you’ve experienced a neuroplastic event,” says Sapolsky.

Until recently, neuroplasticity was thought to occur only during childhood and adolescence but new research has shown that adult brains are capable of creating new connections and forming new neurons, and perhaps even into old age.

So what does plasticity have to do with managing stress? Sapoklsy and others contend that learning new responses to old behaviors can rewire your brain to invoke a calmer response. For instance, says Sapolsky, let’s say an individual goes to a therapist to work out some long-standing issues such as trauma or abuse. As the patient comes to grip with the issue, they start to feel better because during this process, new neural connections are being made. And those new pathways can trigger the brain to release more dopamine, a neurotransmitter involved with feelings of pleasure.


But if you can’t afford therapy, there some things you can do on your own to help retrain your brain. Meditation, visualization exercises and self-hypnosis are intended to train attention for the sake of providing insight and clarity–and calm. Sapolsky recommends meditation. “Find a form of meditation that makes you feel more centered in a way that stays with you throughout the day,” he says, “and you’ve strengthened the prefrontal region of the cortex whose job is it to tone down the amygdala.” The amygdala, Sapolsky explains, is the part of the brain that decides if we should get angry or anxious, and the prefrontal cortex is the part that makes you stop, think and find solutions.

Alvaro Fernandez, a cofounder of Sharp Brains, an independent research firm that specializes in brain health, says that rewiring the brain can be effective both long-term and to immediately calm feelings of stress, but the brain has to be rewired by employing two methods: “One, to ignore the distractors (stressor) and two, to identify and control the feelings when they arise.” Distractions are easily avoided if you know what they are. If, for example, your stress trigger is traffic or a crowded subway car, you can take proactive steps to ignore them through meditation, deep breathing or other calming steps that can slow the heart rate and keep breathing regulated until the stressor passes.

Goewy recommends another exercise for dealing with stress on a case-by-case basis. He calls it the “clear button.” If you feel yourself reacting to stress–whether you’ve been yelled at by a supervisor or you’re about to walk into an annual review–Goewy suggests holding up your left hand in front of your face. Next, visualize a button in the center of your palm, and imagine that this button will put the fear and the stress center of your brain (the amygdala) on pause.

Press the button with your right hand and hold it while you count slowly to three while breathing deeply. With each number visualize a color: 1, red; 2, green; 3, blue, and on the final exhale, let go of the button and make a decision to let the stress go.

“Each step in the exercise chain is a distraction from the primitive, fearful thought center,” Goeway explains. “When you have removed the stress, you are able to see positive solutions to the problems at hand, and without [going into] a panic mode.”

By employing some of these strategies, individuals can not only reduce the stress in their lives but can also turn once-frightening events into positive endings. It could turn out that being chastised by a supervisor might give you a chance to evaluate your own performance and step it up a notch so the next annual review might yield a raise or a promotion.

Five Tips For Stress-Free Living
1)   Get Physical

One of the most beneficial and natural remedies for stress is exercise, “says Kerri O’Brien, director of Life Fitness. “Here are two reasons why: Beta endorphins in our brain are produced when we exercise–this is the magic substance that gives a sense of well-being. Also, exercise uses up the excess adrenaline that stress creates, instantly reducing stress levels.”
 

 

2)   Just Say No

The Mayo Clinic recognizes that an overloaded schedule can lead to stress. There are countless worthy requests out there just waiting to eat up your free time and increase your stress. It’s easy to create stressful situations in your life if you don’t turn down requests for your time and talents.

According to the Harvard Women’s Health Watch, sleep loss may result in irritability, impatience, inability to concentrate and moodiness. Too little sleep can also leave you too tired to do the things you like to do, which can in turn increase stress.

3)   Not What You Do, But When

“What you do–listen to a relaxation tape, do yogic breathing, meditate, nap–matters less than when you do it,” say Aniela and Jerzy Gregorek, weightlifting champions and authors of The Happy Body: The Simple Science of Nutrition, Exercise and Relaxation. “You need to do it immediately after a stress peak, and you need to repeat it often if you will be undergoing an extended period of stress.”

“Positive thinking. It adds nothing to your to-do list, it creates instant good thoughts and helps to shift away from the negative thinking,” says Don Goewy, author of Mystic Cool.

“Take a few deep breaths,” says Michael Ellner, a self-described creative stress management expert, “and imagine that all of the unnecessary tensions are draining from your mind and body. Imagine the last time you laughed out loud, or felt truly loved and appreciated.” The more this visualization becomes clear, the more you will be able to control your mindset and master your stress. Practicing this mental exercise several times a day will condition your brain to automatically release stress-reducing peptides and hormones.

 

 

4)   Girl Talk

For women, spending time with girlfriends has been shown to be good for mental health. Amy Wechsler, M.D., a board certified in dermatology and psychiatry, says to schedule in time with other female friends to ward off stress as laughter has been shown to decrease cortisol levels in women.  

One way to get stress handled is to understand more about it,” says spiritual guru Lynn Scheurrell. She describes the “Four Ds: discontent, disconnect (from self and others), disharmony or dis-ease (things not being easy and/or physical illness).” If any of these are present, there is a stressor, and by understanding where stress comes from, Scheurell says you’ll be better equipped to cope with it.
 

5)   Get Organized

“Living in chaos can create stress,” says professional organizer Sarah Kleinberg. “Most of us don’t realize that cluttered homes can cause anxiety (when we look for keys and lost items), cost us money (when we have to pay late fees on bills) and cancel out peace of mind (sitting in a cluttered room can drain your energy without your even realizing it).” Try sorting laundry or cleaning a small, manageable area of your home to clear your mind.

IBM researchers have delivered a breakthrough that could have a major impact on the power consumption and carbon footprint of data centers, and even the way companies heat their offices.

The project, called Aquasar, is a water-cooled supercomputer that consumes 40% less energy than a comparable system using today’s air-conditioned methods. Plus, the system takes the waste heat that it pulls from the servers and feeds it into the building’s heating system to help warm nearby offices. When you combine these two developments, the result is a carbon footprint that is reduced by up to 85%.

The diagram below shows how Aquasar works:

Announced a year ago, the project is now fully operational using special water-cooled IBM BladeCenter Servers at the Swiss Federal Institute of Technology Zurich (ETH Zurich). The work itself is part of a three-year collaboration between scientists and engineers from IBM and ETH Zurich. The official name of the study is “Direct use of waste heat from liquid-cooled supercomputers: the path to energy saving, emission-high performance computers and data centers.”

There is no commercial product that IBM is marketing with Aquasar yet, but we should reasonably expect the company to integrate this development into its data center portfolio in the years ahead.

Dr. Bruno Michel, manager of Advanced Thermal Packaging at IBM Research-Zurich, said, “With Aquasar we achieved an important milestone on the way to CO2-neutral data centers. The next step in our research is to focus on the performance and characteristics of the cooling system which will be measured with an extensive system of sensors, in order to optimize it further.”

Prof. Dimos Poulikakos, head of the Laboratory of Thermodynamics in New Technologies at ETH Zurich, said, “With Aquasar, we make an important contribution to the development of sustainable high performance computers and computer system. In the future it will be important to measure how efficiently a computer is per watt and per gram of equivalent CO2 production.”

Here’s a quick 2-minute video clip that further explains and demonstrates the Aquasar breakthrough:

Aquasar Super Computer

Watch the video…