Category: Cardiovascular Disease

Probing the Electrical Connections Between Heart Cells

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Harvard Medical School researchers have updated our understanding on how electrical impulses in the heart travel from cell to cell. Their findings are published in the journal Biophysics Reviews.

Disturbances of the bioelectrical processes behind heart’s rhythm can result in cardiac arrhythmias, a common ailment that can lead to illness and death.

A pacemaker within the heart takes the role of an electrical clock, signalling the heart to contract. The whole muscle moves simultaneously, because each individual cell inside of it contracts in a coordinated manner and within a short time interval.

To accomplish this, the pacemaker’s initial electrical impulse rapidly propagates through cells across the heart.

“If one cell is excited electrically and the other is not, the excited cell becomes positively charged inside, and the resting cell is still negatively charged inside. As a consequence, a voltage gradient builds up between the cells,” explained study author André Kléber. “If you have a voltage gradient and a pathway with a low electrical resistance, a local current will flow.”

The connections between cells which make up the low resistance pathway and facilitate the current flow are called gap junctions. Each is made up of numerous channels, which are formed when specific proteins from one cell connect to and fuse to the proteins from another cell. According to Kléber, the fusing proteins look like placing the tips of your fingers on one hand to the fingers on the other hand.

The researchers investigated the properties of gap junctions and connexins, their constituent proteins. Kléber explained that one reason why gap junction channels are interesting is because they are a highly dynamic system in equilibrium. The creation of the channels equals the destruction.
“The turnover is very short,” he said. “On one hand, the system is very stable during your whole life. On the other hand, if you measure it, it is constantly cycling in periods of a few hours.”

The proteins found in gap junctions are also important for processes not directly related to cell-cell connections, like mitochondrial function, which produces energy, and trafficking, which transports molecules from their synthesis site to their site of action in the cell interior.

“You have to refrain from the idea that if you define the role of a protein in the body, that it has only a single function,” said Kléber. “Nature is much, much smarter than human beings.”

Source: American Institute of Physics

Journal information: Kléber, A.G & Jin, Q., (2021) Coupling between cardiac cells—An important determinant of electrical impulse propagation and arrhythmogenesis. Biophysics Reviews. doi.org/10.1063/5.0050192.

Young Boy’s Triumph Over Rare Heart Condition

Photo by Danijel Durkovic on Unsplash
Photo by Danijel Durkovic on Unsplash

Hannah Lewis was expecting to learn the sex of her first child at 20 weeks of her pregnancy. Anxious about becoming a mother at just 19, Lewis was thrilled when she learned she was having a boy.

However, with a worried look on her face, her doctor told her that the baby’s organs looked healthy – except for his heart.

The baby was diagnosed with hypoplastic left heart syndrome, or HLHS, a rare condition where the heart’s left side is underdeveloped, doubling the workload for the right side. Days later, doctors at a children’s hospital in Nashville, Tennessee, confirmed the diagnosis.

But Lewis said her faith gave her the strength to believe she was meant to raise this child as a single mother, as well as her own experiences being raised by a single mother herself.

The rest of the pregnancy was filled with checkups and tests but remained uneventful. Then, at 37 weeks, doctors realised he was developing foetal hydrops, a life-threatening condition in which an abnormal amount of fluid accumulates in the tissue around the lungs, heart or abdomen, or under the skin.

Even in shock from induced labour followed by a caesarean, she remembers hearing her son’s first cries:

“They let me see him for just a second,” she said. “I loved him at first sight obviously, but I was super scared because they took him directly to the heart cath lab and for like 12 hours, we didn’t know what was going on. I was very sick so they wouldn’t let me go see him.”

She named him Bennett after learning the moniker means “God’s gift of hope” or “little blessed one”.

“It was so fitting for what he was about to face,” Lewis said.

HLHS is usually treated with either three different surgeries at certain stages of development or a heart transplant.

Because of the complications introduced by foetal hydrops, Bennett Sayles was 6 days old when he underwent his first open-heart surgery. Although the procedure went well, Bennett remained in critical condition on a ventilator. Then, when he was 2 months old, he had a stroke.

After three open-heart surgeries, 9 month old Bennett had stabilised enough to go home. But shortly before he was discharged, he went into cardiac arrest, and was without a heartbeat for six minutes.

“Then, out of nowhere, his heartbeat came back and it was strong,” Lewis said.

Two weeks later, days before his first Christmas, Bennett went home for the first time. After he turned 2, Bennett underwent the second HLHS surgery, which didn’t work and days later, he needed a fifth open-heart surgery.

Some weeks later he went home, but in hours, Bennett was back in the emergency room with staph infection in his chest. However, Bennett made it home again in time for Christmas. And ever since that series of setbacks, things have improved for him.

“His mental capacity is anywhere from 3 to 5 years old, but he’s got this amazing personality,” Lewis said. “He’s just got such a caring heart. When he’s in the room, he really does light it up and he changes the way you see things. I’m inspired every day because of how amazing he is and he doesn’t let anything hold him back or stop him.”

Two years ago, Bennett’s doctors determined that he would never be a candidate for the other surgeries needed to treat HLHS. He could, however, become eligible for a heart transplant.

“It’s debatable whether he’ll get there, but having known Bennett for the last nine years is not surprising at all that he has progressed to this point,” said Dr. Gerald Johnson, the boy’s paediatric cardiologist. “One of the beauties of working with kids is that they fight and they work to get better, and they work through things in ways that we as adults don’t necessarily do. Bennett’s been a particular fighter on that score and his mother is very proactive and in tune with his needs.”

Raising Bennett has taught Lewis and her family to focus on the present. “We don’t know what’s in store for Bennett,” Lewis said. “He could live his whole life like this or we can have him just a few more years. We love every minute we get to have with him.”

Source: American Heart Association

Listening to Vocal Music Aids in Stroke Patient Rehabilitation

Photo by Adrian Korte on Unsplash

Research has shown that listening to music with singing daily aids language recovery in stroke patients. However, the neural mechanisms behind the phenomenon have remained unknown thus far.

Researchers at the University of Helsinki and the Turku University Hospital Neurocentre compared the effect of listening to vocal music, instrumental music and audiobooks on the structural and functional recovery of the language network of patients who had suffered an acute stroke. The study also investigated the links between such changes and language recovery during a three-month follow-up period.

The results showed that listening to vocal music improved the recovery of the structural connectivity of the language network in the left frontal lobe compared to listening to audiobooks. These structural changes correlated with the recovery of language skills.

“For the first time, we were able to demonstrate that the positive effects of vocal music are related to the structural and functional plasticity of the language network. This expands our understanding of the mechanisms of action of music-based neurological rehabilitation methods,” said Postdoctoral Researcher Aleksi Sihvonen.

Aphasia, a language impairment resulting from a stroke, is a source of considerable suffering for patients and their families. Current therapies aid the rehabilitation of language impairments, but the results are variable and the necessary rehabilitation is often not sufficiently available and early enough.

“Listening to vocal music can be considered a measure that enhances conventional forms of rehabilitation in healthcare. Such activity can be easily, safely and efficiently arranged even in the early stages of rehabilitation,” Sihvonen said.

According to Sihvonen, listening to music could inexpensively boost normal rehabilitation, or be an option for rehabilitating patients with mild speech disorders when other rehabilitation options are scarce.

After a disturbance of the cerebral circulation, the brain needs stimulation to make as good a recovery as possible. Conventional rehabilitation methods aim to provide this as well.

“Unfortunately, a lot of the time spent in hospital is not stimulating. At these times, listening to music could serve as an additional and sensible rehabilitation measure that can have a positive effect on recovery, improving the prognosis,” Sihvonen added.

Source: University of Helsinki

Journal information: Sihvonen, A.J., et al. (2021) Vocal Music Listening Enhances Poststroke Language Network Reorganization. eNeurodoi.org/10.1523/ENEURO.0158-21.2021.

Cardiac Surgery Guidelines Updated with Emphasis on Patient Blood Management

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Newly updated multi-society cardiac surgery guidelines have shifted to a comprehensive blood management approach, with no longer simple recommendations on transfusion.

An update to the 2011 recommendations from the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists, now in collaboration with the American Society of ExtraCorporeal Technology, and the Society for the Advancement of Patient Blood Management (SABM), has been put out. It is available online in the Annals of Thoracic Surgery.

Since the last version, there has been so much new evidence that Pierre R. Tibi, MD, of Yavapai Regional Medical Center in Prescott, Arizona, and colleagues revised or added 23 recommendations and scrapped others.

Probably the biggest change is going from ‘blood conservation’ to the broader ‘patient blood management‘ (PBM) approach, Dr Tibi told MedPage Today.

“Basically we’re considering blood as another vital organ,” he said. “Why that is important is because now we look at a patient’s blood system as an organ that needs to be assessed and treated for the sake of that organ and not simply to decide when or when not to transfuse.”

Recommendations range from preoperative assessment of bleeding risk and anaemia to intraoperative perfusion and blood salvage practices to postoperative treatment with human albumin for volume replacement.

“Most hospitals around the U.S. are acutely aware of patient blood management and, to some degree or another, are implementing many of the things we are talking about,” noted Tibi, who is the most recent past president of SABM. Nationwide, the amount of blood transfused in cardiac surgery has dropped 45% in the past 10 to 15 years but still ranges widely across centres.

A broadly endorsed guideline like this emphasising the importance of a whole-patient strategy should hopefully standardize effective practices and move insurers to cover them, he suggested.

The guideline, for example, gives preoperative assessment of anaemia and its treatment with IV iron and erythropoietin-stimulating agents, if there is time, a class IIA endorsement. Anaemia is widespread, with possibly as many as 40% of patients having it, with one in 10 being under the 8 mg/dL haemoglobin threshold.

“There is a distinct correlation between preoperative anemia and worse clinical outcomes in most studies,” the guidelines note. “Usually, the greater the anemia, the more severe the complications.”

However, preoperative anaemia is “very, very underrecognised and undertested,” Dr Tibi said. While there isn’t always time to reverse anaemia that is found before cardiac surgery, he pointed out that “most of the factors in elective heart surgery have to do with insurance and Medicare. … Oftentimes the treatment for anaemia is not covered by various entities and is too expensive for patients to cover themselves.”

Other notable updates included a class IA recommendation for red blood cell salvage with centrifugation when patients are on cardiopulmonary bypass and the addition of recommendations for the assessment and treatment of patients on anticoagulants.

The guideline, for example, says to withdraw ticagrelor (Brilinta) at least 3 days, clopidogrel (Plavix) 5 days, and prasugrel (Effient) 7 days prior to elective cardiac surgery, while other non-vitamin K oral anticoagulants (NOACs) should be stopped at least 2 days in advance.

“Despite their advantages, NOACs present some periprocedural challenges for operations with a high-risk bleeding profile,” the document says. “Available measurement assays to assess anticoagulation for NOACs are imprecise, and the availability of reversal agents is limited.”

If point-of-care testing with thrombin clotting time is available for dabigatran (Pradaxa), or anti-factor Xa assays for apixaban (Eliquis) and rivaroxaban (Xarelto), in the case of emergent surgery, the guidelines recommend their use.

Source: MedPage Today

Journal information: Tibi P, et al “STS/SCA/AmSECT/SABM update to the clinical practice guidelines on patient blood management” Ann Thor Surg 2021; DOI: 10.1016/j.athoracsur.2021.03.033.

Medical Device Warning for Certain Apple Devices

Apple has released a list of its products that it advises should be kept a “safe distance” away from sensitive medical devices such as pacemakers and implanted defibrillators. These products are iPhone 12 models, Apple Watch and MacBook Pro. 

A number of consumer-electronic devices contain components, such as magnets, which are known to interfere with medical devices. A number of other manufacturers, for example Samsung and Huawei, have issued similar guidance for some of their products.

Heart health is a promoted feature of some Apple products; certain Apple Watches can make electrocardiogram tests and display the results to the user, as well as recording the data for later medical examination. A number of studies have shown that Apple watches can detect cardiovascular problems such as atrial fibrillation with a fairly high degree of sensitivity. However, the current notice warns of the risks posed by components in some products.

“Under certain conditions, magnets and electromagnetic fields might interfere with medical devices,” Apple wrote, noting “implanted pacemakers and defibrillators might contain sensors that respond to magnets and radios when in close contact”.

Implanted defibrillators send electrical pulses to regulate abnormal heart rhythms. Apple said the listed products should be kept more than 15cm away from medical devices, double that if they are wirelessly charging.

The support page that listed the devices, had said earlier this month that iPhone 12 models were “not expected to pose a greater risk of magnetic interference to medical devices” than other iPhones.

However, the website MacRumours, which first noted the list, pointed to research suggesting that the iPhone 12 could interfere with implanted devices.

A study published June 2 in the Journal of the American Heart Association found that “Apple’s iPhone 12 Pro Max MagSafe technology can cause magnet interference”, and so had the potential “to inhibit life-saving therapy”.

The researchers acknowledged the study’s small scale as a limitation, though in a press release lead investigator Dr Michael Wu wrote that they were surprised by the strength of the magnets in the iPhone 12.

“In general, a magnet can change a pacemaker’s timing or deactivate a defibrillator’s life-saving functions, and this research indicates the urgency for everyone to be aware that electronic devices with magnets can interfere with cardiac implantable electronic devices.”

However Marie Moe, a computer security consultant for Mnemonic, told the BBC she was not worried.

“These Apple gadgets are generally not emitting large magnetic fields, unlike heavy machinery, big concert speakers or welding equipment that anyone with a pacemaker should be more concerned about getting in close proximity to,” she said. She is a pacemaker user herself and studies their use.

Ms Moe added that magnets as strong as those in the iPhone 12 could only put the pacemaker into “a kind of safety mode where the pacing is constant”, which would revert back once the device was removed.

Jo Whitmore, senior cardiac nurse at the British Heart Foundation, agreed that devices kept at a safe distance were not cause for concern. “It’s perfectly OK to use a smartphone when you have a pacemaker, and they’re designed to return to normal settings once the magnet is moved away,” she said.

She added that patients should check the device instructions or talk to the manufacturer if they are concerned, and they could also contact their doctor or pacing clinic.

Source: BBC News

After a Stroke, Muscles Lose Basic ‘Building Blocks’

Muscle sarcomeres (consecutive green lines), the smallest functional unit of muscle, from inside a living human. Credit: Northwestern University

In a new study of stroke patients, researchers have discovered that, in an attempt to adapt for an unusable arm, muscles actually lose sarcomeres — their smallest, most basic building blocks.

Patients that have suffered a stroke are often unable to use the arm on their affected side. Sometimes, they end up holding it close to their body, with the elbow flexed. Northwestern University and Shirley Ryan AbilityLab researchers found out why this happens.

Stacked end to end (in series) and side to side (in parallel), sarcomeres form the length and width of muscle fibres. By imaging biceps muscles with three noninvasive methods, the researchers found that stroke patients had fewer sarcomeres along the length of the muscle fibre, resulting in the muscle structure being shorter overall.

This finding is consistent with the common patient experience of abnormally tight, stiff muscles that resist stretching, and it suggests that changes in the muscle potentially amplify existing issues caused by stroke, which is a brain injury. The team hopes this discovery can help improve rehabilitation techniques to rebuild sarcomeres, ultimately helping to ease muscle tightening and shortening.

“This is the most direct evidence yet that chronic impairments, which place a muscle in a shortened position, are associated with the loss of serial sarcomeres in humans,” said senior author Wendy Murray. “Understanding how muscles adapt following impairments is critical to designing more effective clinical interventions to mitigate such adaptations and to improve function following motor impairments.”

Murray is a professor of biomedical engineering at Northwestern’s McCormick School of Engineering, a professor of physical medicine and rehabilitation at the Northwestern University Feinberg School of Medicine and research scientist at the Shirley Ryan AbilityLab. The research was completed in collaboration with Julius Dewald, professor of physical therapy and human movement sciences and of physical medicine and rehabilitation at Feinberg, professor of biomedical engineering at McCormick, and research scientist at Shirley Ryan AbilityLab.

Measuring just 1.5 to 4.0 micrometres in length, sarcomeres are made up of two main proteins: actin and myosin. When these proteins work together, they enable a muscle to contract and produce force. Even though previous animal studies have found that serial sarcomeres are lost from muscles after a limb is immobilised in a cast, the phenomenon had never before been demonstrated in humans. The animal studies found that the shorter muscles due to lost serial sarcomeres also became stiffer.

There is a classic relationship between force and length,” explained first author Amy Adkins, a PhD student in Murray’s laboratory. “Given that the whole muscle is composed of these building blocks, losing some of them affects how much force the muscle can generate.”

To conduct the study in humans, the researchers combined three non-invasive medical imaging techniques: MRI to measure muscle volume, ultrasound to measure bundles of muscle fibers and two-photon microendoscopy to measure the microscopic sarcomeres.

Imaging opens new possibilities
Combining these technologies, the researchers imaged biceps from seven stroke patients and four healthy participants. As stroke patients are more affected on one side of their body, the researchers compared imaging from the patients’ affected side to their unaffected side as well as to images from the healthy participants.

In the stroke patients’ affected biceps, researchers found less volume, shorter muscle fibres and comparable sarcomere lengths. After combining data across scales, they found that affected biceps had fewer sarcomeres in series compared to the unaffected biceps. Greater differences between stroke patients’ arms than healthy participants’ arms were seen, indicating that stroke was the cause.

By combining medical imaging to better view muscle structure, the study also establishes that it is possible to study muscle adaptations in sarcomere number in humans. Prior to two-photon microendoscopy, human studies were limited either to examining dissected tissues in anatomy labs, which give imperfect insight into how muscles adapt to injury and impairment, measuring sarcomere lengths during surgery or from a muscle biopsy, which restricts who can participate in the study.

“In almost every facet of our world, there is an important relationship between how something is put together (its structure) and how it works (its function),” the researchers said. “Part of the reason medical imaging is such a valuable resource and clinical tool is that this is also true for the human body, and imaging gives us an opportunity to measure structure.”

Source: Northwestern University

Journal information: Adkins, A.N., et al. (2021) Serial sarcomere number is substantially decreased within the paretic biceps brachii in individuals with chronic hemiparetic stroke. PNAS. doi.org/10.1073/pnas.2008597118.

Do Heart Hormones Drive Nighttime Hypertension?

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In a new series of studies, University of Alabama at Birmingham researchers have described the reasons behind low levels of natriuretic peptides (NPs) in obese individuals. 

First reported six decades ago, NPs are beneficial hormones produced by the heart, and are responsible for blood pressure regulation and the overall cardiovascular and metabolic health of humans. This study also addresses how the disturbance of an individual’s diurnal rhythm of these hormones contributes to poor cardiovascular health in obese individuals.

High blood pressure at nighttime is seen commonly in obese individuals, who already have higher risk of hypertension and poor cardiovascular outcomes. This can contribute to outcomes such as stroke, heart failure, heart attack and cardiac death. But why this impairment of this day-night blood pressure rhythm is not well understood — however, scientists believe that part of the reason lies with NPs.

“All the hormones in the human body have a day-night rhythm,” noted Vibhu Parcha, MD, a clinical research fellow in the Division of Cardiovascular Disease and the first author of both the studies. “It has been hypothesised the NP hormones should also have this rhythm, but this had not yet been demonstrated in humans. Our clinical trial assessed the 24-hour cycle of the NP hormones and compared it to the 24-hour cycle of blood pressure. We also studied how these cycles differ between lean and obese individuals and studied the reasoning behind why obese individuals experience lower levels of NPs.”

Following a rigorous clinical trial of healthy individuals, researchers found that NP hormones have a diurnal rhythm with higher levels in the afternoon and lower levels at nighttime — similar to the 24-hour cycle of blood pressure. In obese individuals however, researchers observed that the relationship between NPs and blood pressure does not function the same way. This leads to higher nighttime blood pressure and increased risk of cardiovascular disease. The low production of NPs combined with a relatively higher elimination of NPs from an obese individual’s system leads to low levels of these beneficial hormones in circulation, which may explain the NP deficiency.

“This is the first time we have seen that NPs, like other hormones, have a 24-hour rhythm,” said senior author Pankaj Arora, MD, a physician-scientist in UAB’s Division of Cardiovascular Disease. “These studies give us a better understanding of NPs and of the reasoning behind the NP deficiency in obese individuals. We now have an FDA-approved medication (LCZ696) that improves circulating NP levels. This medication is considered a first-line treatment for heart failure and may be used to increase NP levels.”

This medication could specifically target NPs and blood pressure if given at the right time of day and could control hypertension with precision, Dr Arora added. These findings point to using a physiologically-driven precision ‘chronopharmacotherapy’ approach to improve the diurnal blood pressure profile in obese individuals.

Source: University of Alabama at Birmingham

Journal information: Vibhu Parcha et al, Chronobiology of Natriuretic Peptides and Blood Pressure in Lean and Obese Individuals, Journal of the American College of Cardiology (2021). DOI: 10.1016/j.jacc.2021.03.291

Statins not Associated With Cognitive Decline

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A new study has found that statin use in adults 65 years old or older is not associated with incident dementia, mild cognitive impairment (MCI) or decline in individual cognition domains.

Major health concerns in the elderly, cognitive decline and dementia affect about 10% of people over 60 years old. Statins are used to reduce low-density lipoprotein cholesterol, and are a fundamental treatment for prevention of primary and secondary cardiovascular disease (CVD) events. 
In 2012 the Food and Drug Administration issued a warning about cases of apparent short-term cognitive impairment with statin use, while acknowledging that the cardiovascular benefits outweigh their risks. Systematic reviews have since shown insufficient evidence on the impact of statins, and research has shown mixed results, with some showing a neurocognitive benefit of statins and others reporting a null effect.

“With statins being increasingly prescribed to older adults, their potential long-term effects on cognitive decline and dementia risk have attracted growing interest,” said lead author Zhen Zhou, PhD, Menzies Institute for Medical Research at the University of Tasmania. “The present study adds to previous research by suggesting that statin use at baseline was not associated with subsequent dementia incidence and long-term cognitive decline in older adults.”

Researchers of this study analysed data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial. ASPREE was a large prospective, randomized placebo-controlled trial of daily low-dose aspirin with adults 65 or older. One of the key selection criteria of ASPREE was that participants had to have a score of 78 for the Modified Mini-Mental State Examination test, a screening test for cognitive abilities, at enrollment.

The study had 18 846 participants, grouped by their baseline statin use (31.3% of participants) versus non-statin use. The study aimed to measure outcomes including incident dementia and its subclassifications (probable Alzheimer’s disease [AD], mixed presentations); MCI and its subclassifications (MCI consistent with AD, MCI-other); changes in domain-specific cognition including global cognition, memory, language and executive function, and psychomotor speed; and in the composite of these domains.

After a median of 4.7 years of follow-up, researchers found 566 incident cases of dementia (including probable AD and mixed presentations). Compared with no statin use, statin use was not associated with risk of all-cause dementia, probable AD or mixed presentations of dementia. There were 380 incident cases of MCI found (including MCI consistent with AD and MCI-other). Compared to no statin use, statin use was not associated with risk of MCI, MCI consistent with AD or other MCI. No statistically significant difference in the change of composite cognition and any individual cognitive domains between statin users versus non-statin users was seen. However, researchers did find interaction effects between baseline cognitive ability and statin therapy for all dementia outcomes.

The researchers acknowledged several limitations, including observational study bias and lack of data on the length of prior use of statins; and the dose of statins was not recorded in the ASPREE trial, so their effects could not be fully explored. Researchers conclude the study must be interpreted with caution and will require confirmation by randomized clinical trials designed to explore the neurocognitive effects of statins in older populations.

In an accompanying editorial comment, Christie M. Ballantyne, MD, professor at Baylor College of Medicine in Houston, noted study limitations that the authors address, but agreed the findings suggest statins do not contribute to cognitive decline.

“Overall, the analysis was well done, and its main strengths are a large cohort with a battery of standardised tests that allowed the investigators to track both cognition and incidence of dementia and its subtypes over time,” Ballantyne said. “Lingering questions such as the one raised by this analysis regarding potential adverse effects of statins in individuals with mildly impaired cognition can only be answered in randomised controlled trials in the appropriate age group and population and with appropriate testing and adequate follow-up. In the meantime, practising clinicians can have confidence and share with their patients that short-term lipid lowering therapy in older individuals, including with statins, is unlikely to have a major impact on cognition.”

Source: American College of Cardiology

Walking Faster Helps Stroke Survivors to Dual-task

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Training stroke survivors to walk faster during recovery can help improve their ability to perform a task at the same time, known as dual-task walking.

Stroke survivors often struggle to walk and perform cognitive tasks at the same time, for example, walking and holding a conversation, or planning what to do next. To effectively walk in the community, cognitive effort is needed to navigate safely and deal with distractions. Many people are unable to regain this ability after a stroke.

Dual-task training ineffective

To improve the ability to walk and think at the same time, rehabilitation approaches have focused on practising walking and at the same performing a task needing cognition, known as dual-task training. Previous research led by Oxford Brookes University and the University of Oxford found that this training did not improve people’s ability to dual-task walk any more than just walking training.

Researchers reasoned that why people struggle with dual-task walking after a stroke may instead be linked to their walking automaticity – the pattern our brains run which means not having to think about walking. This pattern is linked to the cyclic pattern of walking whereby one step ‘signals’ the next step to follow. When walking very slowly, this pattern could be disrupted so that walking is more like independent steps, rather than a cycle.

Faster walkers improved dual-task walking

The new research re-examined the data to compare how slower walkers and faster walkers responded to dual-task training.

“When we compared slower walkers and people who walked at a faster pace – still slower, but closer to walking speeds we expect to see in people who have not had a stroke – both increased their walking speeds after the training,” said Dr Johnny Collett, Senior Clinical Research Fellow in the Centre for Movement, Occupational and Rehabilitation Sciences at Oxford Brookes University.

“However, those who could walk faster at the beginning of the training also improved their ability to walk and think at the same time.”

Advanced brain imaging tracked responses to training

As part of the study, researchers tracked how people’s brains responded to the training using advanced brain imaging. Changes found in the brain supported the findings that stroke survivors who walked slower, had a less automatic control of  walking. Those who walked at a faster pace had changes in the brain consistent with adaptations needed for controlling gait in more complex environments.

“These findings show that, for those who walk slowly, initially focusing on improving walking speed may increase their capacity to improve dual-task walking,” added Dr Collett. “Greater consideration of walking automaticity may help to better tailor intervention and direct a staged approach of increasing complexity to make people better able to walk in the community.”

Importance for rehabilitation

Dr Rubina Ahmed, Director for Research and Policy at the Stroke Association said: “Stroke strikes every 5 minutes and has devastating physical and mental impacts. Whilst four out of five stroke survivors recover the ability to walk, most find it hard outside of hospital which has a big impact on their well-being and independence. By funding this research our charity has helped to highlight that training focused on walking speeds could be an important part of rehabilitation for some stroke survivors’ recoveries. Research like this is key to finding new treatments and improving stroke care, so that stroke survivors can regain the mobility and independence they need to rebuild their lives.”

Source: Oxford Brookes University

Journal reference: Collett, J., et al. (2021) Dual-task walking and automaticity after Stroke: Insights from a secondary analysis and imaging sub-study of a randomised controlled trial. Clinical Rehabilitation. doi.org/10.1177/02692155211017360.

Drop in Heart Attacks Linked to COVID Pandemic

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A sharp drop in heart attacks in Finland last year seems to be a result of the COVID pandemic, doctors believe.

Cardiologist Mika Laine noticed a roughly 30 per cent reduction in the number of patients suffering myocardial infarction at Helsinki University Central Hospital in April and May 2020. But what was even more surprising was that this was not an isolated occurrence.

“When we started to study this further, we noticed that exactly the same phenomenon happened everywhere else in Finland and also in other countries in Europe and in the United States. So it was a kind of global phenomenon that happened during the COVID pandemic,” he told Euronews.

What was behind the drop?

Dr Laine is of the opinion that the fall in heart attack patient numbers results from changes made in response to the COVID outbreak.

“We have the exact same genes that we had a year ago, two years ago. So it has to be something in the environment that has changed,” he said. One major factor could be the massive global shift to remote working for many people, as a result of the lockdowns.

“People are at home, they are less stressed because they don’t need to go through morning traffic, hurry to work and so forth,” Dr Laine added.

EU Science Hub data shows that even before the pandemic, Finns worked remotely more than almost any other EU country. Last May, EU labour research body Eurofound revealed that Finnish workers made the fastest switch to teleworking in the EU, with nearly 60 per cent switching over.

“We also see this decrease in those people who are retired, who don’t go to work, so it cannot be just because you’re commuting,” said Dr Laine.
He however cautioned that there could be other factors behind the fall in heart attack patients.

Was there a real fall in heart attacks in 2020?

“We know that many people stopped smoking because smoking was associated with severe COVID mortality,” he said.

Better air quality in urban areas as a result of the lockdown could be another cause, Laine said, since airborne particles are known to be a risk factor for heart disease.

However not all are convinced that the pandemic had a positive impact on patients with all types of heart conditions.

Research published in the Journal of the American College of Cardiology in January found that, during the early phase of the pandemic, deaths due to ischaemic heart disease and hypertensive diseases increased in some parts of the US. Some patients may have died as a result of avoiding hospital visits due to infection fears, the researchers noted. 

A temporary or permanent effect?

With Finland, however,Dr Laine believes that was not the case.

“We haven’t seen any increase in mortality in cardiac diseases and so currently we think that it’s a true decrease in the number of cases and not because patients are not seeking help,” he said. “People were not dying at home to myocardial infarction”.

According to Dr Laine, the number of heart attack patients in Finland remains about 5 per cent lower than average, despite the easing of COVID restrictions.

“I think this is a typical example that environmental factors can have profound effects on myocardial infarction. And I think it’s motivating us to change our lifestyle healthier,” Dr Laine said.

Source: EuroNews