Heart diagram. Credit: Wikipedia
What happens in the moments just before death is widely believed to be a slowdown of the body's systems as the heart stops beating and blood flow ends.
But a new laboratory study by the University of Michigan Medical School reveals a storm of brain activity that erupts as the heart deteriorates and plays a surprising destabilizing role in heart function.
This near-death brain signaling may be targeted to help cardiac arrest patients survive. Most of the more than 400,000 Americans who experience cardiac arrest at home, at work or in public die without immediate help.
"Despite the loss of consciousness and absence of signs of life, internally the brain exhibits sustained, organized activity and increased communication with the heart, which one may guess is an effort to save the heart," says senior study author Jimo Borjigin, Ph.D., associate professor of neurology and associate professor of molecular and integrative physiology.
However the brain signaling at near-death may, in fact, accelerate cardiac demise, according to the study published in this week's PNAS Early Edition.
Researchers with backgrounds in engineering, neuroscience, physiology, cardiology, chemistry, and pharmacology looked at the mechanism by which the heart of a healthy person ceases to function within just a few minutes without oxygen.
While the animal study examined asphyxia-induced cardiac arrest, sudden cardiac death can also follow fatal cardiac arrhythmias, ischemic stroke, traumatic brain injury, brain hemorrhage and epilepsy.
For the study, performed in rats, researchers simultaneously examined the heart and brain during experimental asphyxiation and documented an immediate release of more than a dozen neurochemicals, along with an activation of brain-heart connectivity.
Following a steep fall of the heart rate, brain signals strongly synchronized with the heart rhythm, as visualized beat-by-beat using a new technology developed in the Borjigin laboratory called electrocardiomatrix.
According to the study, blocking the brain's outflow significantly delayed ventricular fibrillation, in which the lower chambers of the heart quiver and the heart cannot pump any blood. It's the most serious cardiac rhythm disturbance.
"The study suggests that a pharmacological blockade of the brain's electrical connections to the heart during cardiac arrest may improve the chances of survival in cardiac arrest patients," Borjigin says.
In previous work, Borjigin and her colleagues demonstrated significant organized activation of the brain in animals undergoing cardiac arrest. This new study provides a neurochemical foundation for the surge in brain activity and a brain-heart connectivity that may be targeted to lengthen detectable brain activity.
Explore further: Study shows poor heart function could be major risk for Alzheimer's disease
More information: Surge of corticocortical and corticocardiac neurotransmission in dying animals, PNAS, http://ift.tt/1JgKsxc
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Heart diagram. Credit: Wikipedia
What happens in the moments just before death is widely believed to be a slowdown of the body's systems as the heart stops beating and blood flow ends.
But a new laboratory study by the University of Michigan Medical School reveals a storm of brain activity that erupts as the heart deteriorates and plays a surprising destabilizing role in heart function.
This near-death brain signaling may be targeted to help cardiac arrest patients survive. Most of the more than 400,000 Americans who experience cardiac arrest at home, at work or in public die without immediate help.
"Despite the loss of consciousness and absence of signs of life, internally the brain exhibits sustained, organized activity and increased communication with the heart, which one may guess is an effort to save the heart," says senior study author Jimo Borjigin, Ph.D., associate professor of neurology and associate professor of molecular and integrative physiology.
However the brain signaling at near-death may, in fact, accelerate cardiac demise, according to the study published in this week's PNAS Early Edition.
Researchers with backgrounds in engineering, neuroscience, physiology, cardiology, chemistry, and pharmacology looked at the mechanism by which the heart of a healthy person ceases to function within just a few minutes without oxygen.
While the animal study examined asphyxia-induced cardiac arrest, sudden cardiac death can also follow fatal cardiac arrhythmias, ischemic stroke, traumatic brain injury, brain hemorrhage and epilepsy.
For the study, performed in rats, researchers simultaneously examined the heart and brain during experimental asphyxiation and documented an immediate release of more than a dozen neurochemicals, along with an activation of brain-heart connectivity.
Following a steep fall of the heart rate, brain signals strongly synchronized with the heart rhythm, as visualized beat-by-beat using a new technology developed in the Borjigin laboratory called electrocardiomatrix.
According to the study, blocking the brain's outflow significantly delayed ventricular fibrillation, in which the lower chambers of the heart quiver and the heart cannot pump any blood. It's the most serious cardiac rhythm disturbance.
"The study suggests that a pharmacological blockade of the brain's electrical connections to the heart during cardiac arrest may improve the chances of survival in cardiac arrest patients," Borjigin says.
In previous work, Borjigin and her colleagues demonstrated significant organized activation of the brain in animals undergoing cardiac arrest. This new study provides a neurochemical foundation for the surge in brain activity and a brain-heart connectivity that may be targeted to lengthen detectable brain activity.
Explore further: Study shows poor heart function could be major risk for Alzheimer's disease
More information: Surge of corticocortical and corticocardiac neurotransmission in dying animals, PNAS, http://ift.tt/1JgKsxc
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Electrical signatures of consciousness in the dying brain
The near-death experience reported by cardiac arrest survivors worldwide may be grounded in science, according to research at the University of Michigan Health System.
Study shows poor heart function could be major risk for Alzheimer's disease
A healthier heart could prevent Alzheimer's disease, according to new research at Vanderbilt University Medical Center.
Even mild heart failure can lead to sudden death
Sudden cardiac arrest is a possible cause of death in patients with non-ischaemic cardiac muscle weakness, i.e. a type of heart failure caused by genetics or for which no cause is known. Now, researchers ...
Study links sex hormone levels in the blood to risk of sudden cardiac arrest
Measuring the levels of sex hormones in patients' blood may identify patients likely to suffer a sudden cardiac arrest, a heart rhythm disorder that is fatal in 95 percent of patients.
Unfolded protein response contributes to sudden death in heart failure
A researcher at the Cardiovascular Institute (CVI) at Rhode Island, The Miriam and Newport hospitals has found a link to human heart failure that if blocked, may reduce the risk of sudden cardiac death. The paper, written ...
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Multiple sclerosis patients could benefit from brain boost
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Study provides new insight into what occurs in the brain during the learning process
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Quality of life was good and cognitive function was similar in patients with cardiac arrest who received targeted body-temperature management as a neuroprotective measure in intensive care units in Europe and Australia, according ...
Toward a model of synchrony in brain networks
(MedicalXpress)—Resting state networks (RSNs) in the brain are topographies of neural structures between which lag states propagate due to fluctuations of physical and other activities. Studying these networks ...
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