Nav: Home

New research could reduce the risk of sudden cardiac death

January 20, 2020

Around 26 million people worldwide suffer from heart failure, with more than 50 per cent dying suddenly most likely due to the spontaneous onset of a heart rhythm problem, known as an arrhythmia. The link between the electrical signal that triggers the heart cell to contract (action potential) and consequent ability of the heart to pump blood has been known for nearly 40 years but understanding how and why the heart's electrical rhythm becomes disturbed has remained a major research problem. New research has shown that by changing the time course of voltage change early in action potential it is possible to both withhold a potentially lethal electrical disturbance and improve the strength of cardiac contraction in heart failure at the same time.

The research led by the University of Bristol and funded by the Medical Research Council (MRC) is published today [20 January] in the Proceedings of the National Academy of Sciences (PNAS).

At the cellular level, an identified initiator of cardiac arrhythmias are early after-depolarizations (EADs), but the cellular trigger for EADs in heart failure is unclear. EADs occur during the repolarization phase of the cardiac action potential (AP) where several ionic currents interact to control repolarization. EADs may be produced by reactivation of ionic currents during AP repolarization when the potassium currents forming the "repolarization reserve" are insufficient to maintain the repolarization trajectory of the AP, although why this should occur spontaneously within a steady train of APs is uncertain. Spontaneous calcium (Ca2+) waves inside the cell have also been implicated in EAD generation, but it is unclear how such waves might be initiated.

The study has shown that the reduction in synchronous Ca2+ release early in the AP of failing heart muscle cells promotes the appearance of "late Ca2+ sparks" (microscopic Ca2+ release events) which can propagate, forming Ca2+ ripples and waves. These, in turn, produce an inward sodium-calcium exchange current which opposes AP repolarization. Restoration of AP phase 1 repolarization improved Ca2+ release synchrony and reduced late Ca2+ spark rate, suggesting an entirely new approach to reducing the risk of sudden death in heart failure.

Professor Mark Cannell, Chair in Cardiac Cell Biology in the University of Bristol's School of Physiology, Pharmacology and Neuroscience, who led the research, said: "Our findings suggests that new therapies should be developed with the aim of improving early Ca2+ release by restoring AP phase 1 repolarization and/or restoring t-tubule regularity. This will reduce the risk for potentially lethal heart rhythm problems as well as mitigating the defective excitation-contraction coupling seen in heart failure. Our research proposes an entirely new approach to reducing the risk of sudden death in heart failure and the next step will be to move towards a clinical trial of new drugs."
-end-
Paper

'Arrhythmogenic late Ca2+ sparks in failing heart cells and their control by action potential configuration' by Ewan D. Fowler, Nan Wang, Melanie Hezzell, Guillaume Chanoit, Jules C. Hancox & Mark B. Cannell in the Proceedings of the National Academy of Sciences (PNAS)

University of Bristol

Related Heart Failure Articles:

Top Science Tip Sheet on heart failure, heart muscle cells, heart attack and atrial fibrillation results
Newly discovered pathway may have potential for treating heart failure - New research model helps predict heart muscle cells' impact on heart function after injury - New mass spectrometry approach generates libraries of glycans in human heart tissue - Understanding heart damage after heart attack and treatment may provide clues for prevention - Understanding atrial fibrillation's effects on heart cells may help find treatments - New research may lead to therapy for heart failure caused by ICI cancer medication
Machining the heart: New predictor for helping to beat chronic heart failure
Researchers from Kanazawa University have used machine learning to predict which classes of chronic heart failure patients are most likely to experience heart failure death, and which are most likely to develop an arrhythmic death or sudden cardiac death.
Heart attacks, heart failure, stroke: COVID-19's dangerous cardiovascular complications
A new guide from emergency medicine doctors details the potentially deadly cardiovascular complications COVID-19 can cause.
Autoimmunity-associated heart dilation tied to heart-failure risk in type 1 diabetes
In people with type 1 diabetes without known cardiovascular disease, the presence of autoantibodies against heart muscle proteins was associated with cardiac magnetic resonance (CMR) imaging evidence of increased volume of the left ventricle (the heart's main pumping chamber), increased muscle mass, and reduced pumping function (ejection fraction), features that are associated with higher risk of failure in the general population
Transcendental Meditation prevents abnormal enlargement of the heart, reduces chronic heart failure
A randomized controlled study recently published in the Hypertension issue of Ethnicity & Disease found the Transcendental Meditation (TM) technique helps prevent abnormal enlargement of the heart compared to health education (HE) controls.
Beta blocker use identified as hospitalization risk factor in 'stiff heart' heart failure
A new study links the use of beta-blockers to heart failure hospitalizations among those with the common 'stiff heart' heart failure subtype.
Type 2 diabetes may affect heart structure and increase complications and death among heart failure patients of Asian ethnicity
The combination of heart failure and Type 2 diabetes can lead to structural changes in the heart, poorer quality of life and increased risk of death, according to a multi-country study in Asia.
Preventive drug therapy may increase right-sided heart failure risk in patients who receive heart devices
Patients treated preemptively with drugs to reduce the risk of right-sided heart failure after heart device implantation may experience the opposite effect and develop heart failure and post-operative bleeding more often than patients not receiving the drugs.
How the enzyme lipoxygenase drives heart failure after heart attacks
Heart failure after a heart attack is a global epidemic leading to heart failure pathology.
Novel heart pump shows superior outcomes in advanced heart failure
Severely ill patients with advanced heart failure who received a novel heart pump -- the HeartMate 3 left ventricular assist device (LVAD) -- suffered significantly fewer strokes, pump-related blood clots and bleeding episodes after two years, compared with similar patients who received an older, more established pump, according to research presented at the American College of Cardiology's 68th Annual Scientific Session.
More Heart Failure News and Heart Failure 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

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at Radiolab.org/donate.