TY - JOUR
AU - Nicholls, Mark
AB - Mark Nicholls presents the highlights from the BCS conference, underpinned by extremes; of those in-flight, of polar extremities and diving to hidden depths  The British Cardiovascular Society (BCS) 2017 conference in Manchester during 5–7 June 2017, explored how the heart—human, mammal, and reptilian—reacts and responds when confronted by extreme challenges, whether by the depths of the ocean or the unnatural G forces of gravity experienced by fast-jet pilots. Yet it was also a showcase and platform for innovation, scientific excellence and research, and new frontiers in the study and treatment of cardiology. The British Cardiovascular Society President Dr Sarah Clarke delivered a powerful and poignant opening to the conference, held in Manchester (5–7 June) where only days earlier the city had been stunned and saddened by a terrorist attack. She reflected on an eventful few months within the National Health Service (NHS) with increasing hospital admissions, industrial action from junior doctors, cutbacks, an Accident & Emergency (A&E) crisis and a cyberattack, as well as restructuring of health services across the UK and an NHS ‘in crisis’. Referring to the recent terror attacks in Europe, she continued: ‘We live in a turbulent world; our world leaders are not aligned. But we have come to Manchester…because it is important that we carry on.’ Quoting Helen Keller, the American writer and social activist from 1903 … ‘although the world is full of suffering, it is full also of the overcoming of it’, she reminded delegates that a key part of their role was to overcome suffering, before asking them to stand in a moment’s silence to remember those killed and many more injured in an attack at the end of the Ariane Grande concert in Manchester on May 22 and those who died in London on June 3, before defiantly declaring the 2017 BCS conference open. Maximizing digital data in healthcare Cardiologist and leading healthcare researcher Harlan Krumholz has urged medical practitioners to ‘wake up’ and embrace the potential of digital data generated by patients. Addressing delegates at the British Cardiovascular Society, he expressed fears that practitioners were in danger of being ‘left behind’ as the digital revolution moves forward at ever-increasing speed. As Professor of Medicine (Cardiology) at Yale School of Medicine, he delivered the prestigious Paul Wood Lecture on a theme of ‘Personalised medicine and computational cardiology – enhancing cardiovascular care and health in the next era.’ He said: ‘Data generated every day for a variety of practical purposes can serve as an inexhaustible source of knowledge to fuel learning in a healthcare system.’ But he warned that if medicine wants to take advantage of technology, it must catch up with the digital revolution. He pointed to statistics that show the average American spends 5.6 h on digital devices every day, including those in older age groups, and that medicine has to leverage mobile technologies and recognize the power of this trend. Professor Krumholz also suggested that medicine has not learned to communicate rapidly, effectively, and simply in the way that other sectors such as weather forecasters, retailers, and traffic bulletins, have done with their audiences. ‘Medicine is slow in catching up,’ he said. ‘How are we going to meet people where they are, what are we doing in medicine to make sure digital data is safe, and how are we integrating it into practice?’ He pointed to the transition to electronic health records (EHRs), where he feels health professionals in the USA were slow to get involved as hospitals made the transition—eased with $50bn of funding. In 2008, 9.4% of records were EHR, but by 2015 it was 83.8%. ‘But as physicians we did not get involved, we lost an opportunity to ensure we got the product we needed - and we should not do that again,’ he added. He also said that patients should have access to their own records and have the power to share it in ways that can improve their care and augment research, being partners as ‘citizen scientists.’ The most important element about precision medicine, he continued, is that it can be driven with patients as partners and that the doctors and researchers should recognize the value of patient reported outcome data generated from wearable devices and data collection mobile technologies. He opened by suggesting that data acquisition is an important new dimension to the way doctors approach medicine. ‘Medicine now is more than ever an information science and increasingly a digital information science,’ said Professor Krumholz. Yet he harbours concerns about whether physicians are truly making the best use of it and that they are unlikely to be in a better position with the available data ‘unless we learn to use and develop new knowledge iteratively’ and develop ‘smart enough’ systems to process the data and utilize it. Among his key concerns is that the current medical research enterprises cannot keep pace with the information needs of patients, clinicians, administrators, and policymakers. He said that the digital revolution and new tools and approaches have the potential to augment and accelerate knowledge—producing a new paradigm of a learning healthcare system. As he opened his keynote lecture, he reflected on how Professor Wood believed the hospital archive was a treasure chest of data to be analysed to learn more about the hearts of patients. He commented that Professor Wood was one of the original data scientists, looking for knowledge in data generated in the course of clinical care. He looked back to the time he came to London in 1981, fresh from his studies and working on a project to study primary care in rural areas of the UK. He recalled fondly what he enjoyed about the UK—from McVitie’s chocolate-covered biscuits, to free admission to museums and the vast volumes of the book stores—but most of all he vividly remembered the kindness and care of British physicians towards their patients. He travelled across the country, including to some remote Scottish islands, for four-and-a-half months visiting general practitioners in their surgeries, who were kind and welcoming. ‘What I fell in love with was the way British physicians cared for their patients,’ he recalled. ‘They knew their patients personally and were part of the fabric of the community.’ In today’s hi-tech world, as there was then, he suggested there is no average patient and when it comes to prediction and prognosis, health professionals need to be thinking in more complex ways than just employing crude metrics. He suggested that not enough is made of leveraging the power of a rich past history. He also made the point that some research in prediction spends too much time on ‘telling us something we already know.’ We can ‘do better,’ he said. Professor Krumholz said: ‘Medicine needs to realise that we are in a new era. Health professionals, not the technicians, have to be the key as they understand what patients need and the complexity of the problems that our patients face. Isn’t it great that someone who does not know you, walks in and trusts you because you are a doctor or a nurse. And then you can show them that you are worthy of that trust. The next generation must be deployed in a way that preserves that special nature of our profession? The advances in technology should help us be better, not replace the human touch. It is also time, with regard to technology, for us to start thinking about user experience and user interface. We should be embracing technology but it has got to be technology that will help us and is easy to use – and communicates information effectively.’ He concluded: ‘We should not be afraid of technology when it comes to health. It is better to embrace it—it can make us smarter than ever in looking after large populations. For those training in cardiology today there has never been a more exciting time to be part of this field and technology is a big part of that.’ At the end of the lecture, BCS President Dr Sarah Clarke presented Professor Krumholz with the Paul Wood Medal. Placing cardiology at the heart of space travel Getting astronauts to Mars and back is a major aim of US space agency NASA over the next three decades. Yet a key consideration remains over just how these astronauts will cope with the two-and-a-half-year journey, and what the impact will be on their cardiovascular system. The critical challenges were discussed by space cardiologist Professor Benjamin Levine in the keynote opening lecture to the 2017 British Cardiovascular Society conference. ‘Will the right cardiovascular stuff get humans to Mars: reflections of a Space Cardiologist’ examined some of the health issues faced by astronauts, such as fainting after returning from space missions, which was most prominent in the early days of the space program. That led to experiments on the cardiovascular system and gravity being conducted on the Space Shuttle and Space Lab during the 1990 s to attempt to discover why this occurs. Professor Levine, who is the Director of the Institute for Exercise and Environmental Medicine and Professor of Medicine and Cardiology and Distinguished Professorship in Exercise Science at the University of Texas Southwestern Medical Center, explained that when astronauts go into space there is a shift in the distribution of volume in the circulation with the blood moving away from the legs and into the upper body. This creates what astronauts describe as ‘puffy face bird legs syndrome’ as the legs become thinner and the upper body and face fill out. Bold experiments measuring central venous pressure (CVP) using invasive catheters during launch showed that it rose during the high front-to-back pressure of lift-off, but surprisingly plummeted to zero after entry into space. ‘It turned out that the heart size went up and CVP went down,’ he said, ‘but that left us with the question of how we get lower CVP but a bigger heart.’ The best theory to account for both of these factors, explained Professor Levine, is that when astronauts go into space the weight of the lungs and the chest wall is removed, which emphasizes the external constraining forces on cardiac physiology. Once an astronaut comes back from even 1–3 weeks in space, the supine stroke volume is low and the upright stroke volume is lower still, suggesting that the heart is substantially under-filled when gravity is restored. This low upright stroke volume (similar to when a person is dehydrated or over-heated), can lead to orthostatic hypotension and syncope. Early studies suggested that the problem could be with vascular resistance, he said. So Professor Levine and his team directly measured muscle sympathetic nerve activity (MSNA) and found it increased in space and increased further on the ground, in exact proportion to the low stroke volume. These findings, he said, demonstrated that stroke volume plays a critical role in stimulating arterial baroreceptors, which appeared to be functioning appropriately after short duration spaceflight. The answer then appeared to be cardiac remodelling, or atrophy, in space, combined with hypovolemia, which together seem to be the cause of the low upright stroke volume and increased risk of fainting. To try to answer this, Professor Levine said trial subjects underwent 2–16 weeks of strict head down tilt bed rest, during which the LV mass measured by cardiac MRI continued to go down at the rate of a loss of 1% of heart muscle per week. Yet when doing exercise in bed—such as rowing—loss of heart muscle was prevented, and when the heart was refilled prior to standing, orthostatic intolerance was prevented. One of the most recent pivotal experiments, he said, was conducted with 13 astronauts (nine men and four women) aboard the International Space Station, who had echocardiography performed in space using remote guidance from the ground, and then cardiac MRI pre- and post-flight. When astronauts spent 2 h a day exercising there was no change in heart muscle. From a 6-month flight, there was an 11% reduction in the LV of the fittest astronaut, however with the least fit astronaut the heart actually got bigger from exercise in space. ‘We could determine whose heart got bigger and smaller by the amount of exercise they did, compared to what they usually did before flight,’ he said. Lastly, Professor Levine emphasized that most astronauts are middle aged men and women; and the most likely cause of a medical catastrophe in this age group is coronary heart disease. Working with NASA flight surgeons, Professor Levine and colleagues developed an app to help NASA determine high resolution cardiovascular risk assessment tools (combining ‘standard risk factors’ with coronary artery calcium measurements) to avoid sending high risk astronauts into space for exploration class missions, given that Mars is a long trip: 161 days transit, 573 days on the surface, and 154 days back. Issues space cardiologists can expect to address going forward is the risk of Atrial Fibrillation, visual impairment and radiation which is a known accelerator of atherosclerosis. The next major challenge for the cardiovascular community to discover, he added, is how to eliminate the risk of accelerated atherosclerosis and vascular damage from space radiation. In conclusion, he told his audience that cardiovascular deconditioning occurs with both short and long-term space flight, manifesting as orthostatic intolerance and reduced exercise capacity. The primary factor underlying cardiovascular adaptation to microgravity is a reduction of stroke volume in the upright positon, which is the key mechanism underlying syncope. This adaptation, he added, appears to be due to a combination of cardiac atrophy and hypovolemia but can be prevented by exercise and adequate hydration. An important consideration, in order to interpret data from spaceflight, lies in carefully specifying the comparative position (the adaptive position is somewhere between supine and upright). He said: ‘The gravest risk in spaceflight comes from the technical challenges of flying with your entire environment, for a long time, far from earth.’ However, the most likely catastrophic clinical event would be an acute coronary syndrome, either because of flying an astronaut with pre-existing coronary disease, or accelerating atherosclerosis from radiation, he said. Big hearts and no crocodile tears… It was a bold statement to make to an audience of cardiologists. pt?>But animal eco-physiologist and zoologist Craig Franklin stood determined as he proclaimed to his audience at the British Cardiovascular Society conference that he was planning to discuss the crocodile heart…and ‘going to argue that it is the most sophisticated and complex heart in the animal kingdom.’ Continuing the conference theme of ‘Extremes’ with a focus on ‘Extreme diving in humans and other animals’, Professor Franklin delivered an engrossing lecture on ‘Diving in Crocodiles: cardiovascular intricacies and tricks.’ Opening by looking at the performance and capabilities of some of the 200 species of diving invertebrates—reptiles, birds, and mammals—he drew attention to the Weddell Seal, which can dive down to 200–400 m for 15–18 min and a maximum recorded of 800 m for 82 min; and the Cuvier Beaked Whale, which has been known to dive for 137.5 mi down to 2997 m. The human record holder, Will Trubridge, can dive to 132 m for four minutes unassisted, but it takes weeks for him to recover. (The lecture session also included discussions on cardiovascular risk of diving in the apparently normal human, and diving after cardiac procedures.) Professor Franklin, from the School of Biological Sciences from the University of Queensland, explained that diving vertebrates all have lungs and need to come to the surface to breathe, and that includes the crocodiles we see today which have an evolutionary history stretching back 100 million years. Of the 25 species of crocodile, his work focusses primarily on the extremely aggressive estuarine crocodiles of northern Australia’s Wenlock River and the largest living reptile which can grow to seven metres long and weigh a tonne. It dives for food, to travel or escape predators. ‘Until recently,’ he said, ‘very little was known about the diving of crocodiles but the invention of telemetry has allowed us to understand more about the animals.’ That involves trapping and capturing the mighty beasts and roping the jaw to trigger a death roll to bind and immobilize the reptile before several members of the 20-strong capture team literally lay on it in order to fit the self-releasing telemetry, which can later be retrieved. Tranquilisers are not an option as that would see the animal returning to the water in a sedated state. It is this technology which has enabled Professor Franklin and his team the opportunity to unlock some of the mysteries of the complex crocodile heart. Crocodiles dive for 60–94 min and may only spend a little time on the surface to breathe and recover before diving again. The record dive time is 387 min. ‘How they do that,’ he said, ‘is about managing oxygen, and their unique four-chambered heart. At the start of a dive the heart rate is 45 beats per minute but drops to 10 on the bottom and then returns to 45 when they return to the surface.’ Outlining the physiology of the crocodile heart, he explained how it has two atria and two ventricles, and pulmonary arteries. ‘What is different is that the left aorta emanates from the right ventricle and the right aorta from the left ventricle,’ he continued. There is a single carotid artery and the wall thickness of the right and left ventricles is the same, but there is a foramen of Panizza between the left and right aorta while near the sub pulmonary conus there is a cog-tooth valve. Explaining the flow, he said there is provision for a switch from pulmonary to systemic shunting, but the question is when does that occur? That has the effect of increasing the pulmonary resistance, decreasing the systemic resistance, increasing venous pressure on the right side of the heart and introducing a cardiac control mechanism, he said. The increased input of pressure in the hepatic vein stimulates the pulmonary systemic shunt, he continued, while other evidence shows an active intra-cardiac valve. The pulmonary outflow decreases with adrenaline while the foramen of Panizza has a variable diameter controlled by an adrenergic system. A bolus of adrenaline increases foramen resistance. ‘The reverse flow through the foramen to a single circulation allows blood to be pumped from one side to the head and coronary arteries,’ said Professor Franklin. When does that occur and why? He believes it is an adaptation for diving with an increase in cholinergic tone and decreased adrenergic tone. ‘Occasionally it will see a release of blood and will go to the lungs to pick up oxygen like a scoop tank and re-circulate it,’ he added. ‘What we believe, is that this allows for extended aerobically supported dives.’ When the crocodile dives, it has a lung full of air and heads to the bottom, whereas other mammals dive after exhaling. To further underline this, his team returned to the field with a specially-designed implantable device, captured five crocodiles and fitted it, before releasing them back into their natural environment and monitored them for a month. The battery-powered device, the size of a matchbox, monitored blood flow, blood pressure, ECG, and body temperature. ‘We recorded left and right pressure flow, heart rate and other measures during basking, diving, swimming and feeding. Heart rate in a dive was 7-10 bpm and 40-50 bpm on the surface - from brachycardia to tachycardia. Under diving conditions - and this was the exciting part - we could see shunting and a positive flow to the left aorta from the readings.’ ‘We believe that is how the crocodile is able to extend its dives into hours,’ he concluded. ‘It is a remarkable animal with a remarkable cardiovascular system.’ Extreme flying and the impact of G force on the heart Physicians have been aware of the impact of G-forces and G-induced loss of consciousness for centuries. Indeed, Charles Darwin’s father Erasmus experimented with the idea by observing people lying on mill stones, noting that they became unconscious while spinning around but also that it was ‘something to do with blood.’ The phenomenon—sustained by pilots—was explored by Wing Commander Nic Green from the RAF Centre of Aviation Medicine at RAF Henlow in a conference session focussing on Extreme Flying and the Cardiovascular System. A Defence Consultant in Aviation Medicine, he delivered a presentation entitled The Applied Cardiovascular Physiology of Flight, explaining to delegates that the RAF started working with G-force and episodes of G-induced loss of consciousness through pilots accelerating and manoeuvring in World War One. Tolerance of G-force is generally better when lying down but can be induced in pilots in a centrifuge with visual effects, blackout with loss of blood to the retina and then G-induced loss of consciousness, usually above 4 G. ‘When pilots come around, they are not with it immediately and there is about 30 s where they do not know what is going on, which is not particularly good when you are travelling quickly in the air,’ he said, hence, the RAF’s interest in G-induced loss of consciousness. Blood pressure in the head drops by 23 mmHg per 1 G while there is higher blood pressure in the lower limbs. That sees reduced pressure to the right side of the heart, reduced CVP and decreased ventricular filling. ‘While it can happen in centrifuge training, a survey found that around 20% of RAF pilots have lost consciousness in flight,’ said Wing Commander Green, adding that the fatal Red Arrows crash of 2011 was due to G-induced loss of consciousness. However, he stressed it was more complicated than just a lack of blood pressure in the head and while it is possible to draw a graph for what happens to a pilot’s blood pressure under G-forces, the baroreceptor reflex can see toleration of extra G. And while an individual can lose consciousness when under 4 G or more for four seconds, higher levels of G up to 8–9 G—such as experienced by stunt pilots or combat air crew—can be sustained for briefer periods. He said that there are possible changes of cardiac outline and of coronary blood flow and also the potential to cause arrhythmias due to rapid sympathetic/parasympathetic drive shifts. Pilots can take steps to off-set the effect of G via G-straining (muscle tensing) and anti-G protection such as anti-G trousers which inflate to push blood flow toward the head and main organs. Typhoon aircraft pilots also have access to pressure breathing, automatically forced into lungs when G comes on. During the same session, Wing Commander Ed Nichol, a consultant cardiologist at the Royal Brompton Hospital and a consultant advisor in medicine with the RAF, spoke about Clinical Evaluation and Regulation of Extreme Performance Pilots. As a cardiologist in that environment, he said clinical decision-making is the same as with other patients but coupled with an occupational risk assessment alongside criticality of the task as well as aeronautical considerations, physiology, and increased myocardial oxygen demand. ‘It is not just about G but the heat load effect, pre-existing cardiovascular disease and the potential for arrhythmogenesis alongside the effect of distraction and incapacitation, and the baroreceptor response can be overwhelmed by rapid application of force and sustained high force,’ said Wing Commander Nichol, who is also Chair of the NATO Cardiology working group. Air crew are screened for ischaemic heart disease and across a range of conditions such as atrial fibrillation, hypertrophic cardiomyopathy, recurrent pericarditis, Bundle Branch Block, valve disease, and congenital heart disease with cardiologists assessing fitness to fly. Squadron Leader Gaz Kennedy, officer commanding the Aviation Medicine Flight, outlined The Experience of Extreme Flight and the work of his unit in delivering high-G training, clinical assessments and a motion sickness desensitization programme. He talked through a routine sortie, including dressing a ‘volunteer’ cardiologist—Dr Anthony Nathan—in flying suit, helmet, and G-pants, and also demonstrated the G-restraining manoeuvre. At the polar extremes As a schoolgirl, Sue Flood would regularly write to the BBC seeking the opportunity to work alongside the legendary naturalist and wildlife broadcaster David Attenborough. Yet a few years later, she realized her dream by working as a researcher and assistant producer on Blue Planet—which led her into diving—and then on to work with her hero on Planet Earth. ‘From someone who as a child said they wanted to work with David Attenborough, that was simply a dream come true,’ she told the audience at the British Cardiovascular Society conference. Reflecting on her ‘Adventures at the Polar Extremes – from the North Pole to the Antarctic and in-between!’ she relayed details of her many trips to the Arctic and Antarctic, her fondness for Emperor Penguins and showed spectacular footage of birds and animals on land and in the sea at the Polar regions. That included diving with whales to film them underwater, of Beluga whales trapped in the ice and having to surface to breathe every 20 min at the mercy of circling Polar bears, photographing penguins, and her work alongside the Inuit to learn their traditions and customs. A renowned wildlife and travel photographer (www.sueflood.com), she said: ‘The Polar regions are addictive, they are a fantastic place to travel to and these cold regions draw me back again and again.’ Camping on the ice, she has dived at −25°C in Hudson Bay in winter, cutting a hole in the ice with a chain saw. Wearing a dry suit, she often poured hot water into her gloves to keep her hands warm for as long as possible as she dropped into the water to film invertebrates diving under the ice. At times, Polar bears have become interested in her and her activities but she reflects on the most dangerous occurrences while filming usually involve people or vehicles but she recalls being confronted by a fierce leopard seal once as her most dangerous experience with an animal. There was one time that Sue was camping on the ice and it broke up and started floating away before her team was rescued by a helicopter. Filming the Emperor Penguins remains her favourite activity and she adds: ‘The thing that makes me so interested in my job is to get people inspired by the natural world and appreciate and conserve nature.’ The session also heard from retired vascular surgeon Mr Martin Thomas, who delivered a fascinating presentation on the exploits of polar explorer Sir Ernest Shackleton and of his personal journey following in the explorer’s footsteps. Shackleton, however, would never allow doctors to examine him when he became ill on his polar exploits and pointedly refused to allow physicians to listen to his heart. It was a theme Dr Jan Till, a consultant cardiologist at the Royal Brompton Hospital, picked up on suggesting that the explorer had a heart condition but kept it a secret. Dr Till said there was never any mention of illness in Shackleton’s diaries and that all reference to him becoming unwell—and then recovering—were contained in the writings of his companions. One doctor did suggest that Shackleton had a pulmonary systolic murmur, she noted, but as he was an explorer who had to raise funds for his expeditions, any reference to him being unwell would have scuppered his plans and his livelihood. Despite his condition and periods of illness, Shackleton courageously led his men through the most challenging of polar conditions. When he died in 1922 aged 47, she suggested that he may have had an atrial septal defect. However, she concluded: ‘The feats he performed were even greater because I think he knew something was wrong with his heart.’ Conflict of interest: none declared. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.
TI - British Cardiovascular Society Conference 2017
JF - European Heart Journal
DO - 10.1093/eurheartj/ehx441
DA - 2017-09-07
UR - https://www.deepdyve.com/lp/oxford-university-press/british-cardiovascular-society-conference-2017-24jo0BuMT5
SP - 2578
EP - 2583
VL - 38
IS - 34
DP - DeepDyve
ER -