British military service personnel are pioneering the use of implantable biosensors to study the effects on the heart of exercising at extreme altitudes with low oxygen.
The research forms part of a series of medical studies that will be undertaken during the expedition to summit the North East ridge of Dhaulagiri in Nepal. At 8,167 m, it is the seventh highest point on earth.
Alongside the feat of mountaineering, the joint service team - officially named the British Services Dhaulagiri Medical Research Expedition 2016 (BSDMRE) - will conduct groundbreaking medical research into the effects of altitude on the human body. This will be the first time a military study has done so above 6,000 m and using implanted technology.
The team will climb at extreme altitudes without oxygen, following 6 weeks of acclimatization, aiming to make the summit around May 20.
The main team making the grueling 8,167-m ascent will be involved in two studies looking at the effect of an injection of iron on the body's response to low oxygen levels and measuring heart rate and rhythm during the climb.
In addition to its relevance to sport and exercise science, it is hoped that this data may provide insight into how the heart behaves in the face of disease or illness.
'Expedition may help unpick mechanisms behind critical illness'
The study involves the use of an innovative Medtronic Reveal LINQ device - a 2-inch, wireless, cardiac heart monitor that is implanted under the skin on the chest by a minor surgical procedure. The device will store and upload data from each heartbeat during the expedition by satellite link. This technique will allow the team to collect unique data from the heart during exercise at extreme altitude and low oxygen tensions.
Dr. Christopher Boos, consultant cardiologist and physician, leads the team at Poole Hospital responsible for inserting the climbers with the device, which will automatically transmit the electrical patterns of each heartbeat back to the ground in the UK, for real-time analysis.
"This exciting study brings to life the concept that people can be extremely remotely located, yet still able to rely on quick diagnoses through medical technology," says Dr. Boos. "A climber's cardiac system has never before been so thoroughly studied at such extreme altitudes, and the research will unlock some of the unexplained mysteries of altitude sickness and counteract the life-threatening symptoms it inflicts."
Speaking about the research, expedition leader Surgeon Commander Adrian Mellor says:
"Until recently it has only been possible to collect heart rate data at rest due to the size and difficulty of obtaining a clear electrical recording from the heart at extreme altitudes. Now that we are able to do this, for the first time we will have accurate and sustained readings that will help us understand what happens to the heart rhythm during times of very low oxygen supply.
This and other studies in conjunction with Leeds Beckett and Oxford Universities will help us better prepare soldiers for deployment at high altitude and understand the body's response to critical illness."
"The expedition is a great opportunity to undertake novel medical research during military adventurous training," adds Mellor. "Understanding how the body functions, especially during exercise, under conditions of extreme lack of oxygen, is crucial to understanding how we acclimatize to altitude and, more importantly, may help us better understand some of the mechanisms behind critical illness."
Smallest cardiac monitor currently available
The Reveal LINQ Insertable Cardiac Monitor System is a miniaturized implantable heart monitor designed to help physicians quickly and accurately diagnose irregular heartbeats.
At just one third the size of a AAA battery, it is the smallest cardiac monitor currently available. Implanting the device requires an incision of less than 1 cm, and once in place, it remains just below the skin surface, providing continuous monitoring of the heart. This gives physicians a reliable snapshot of each patient's cardiac activity, allowing them to accurately diagnose and monitor each patient.
Though small, the Reveal LINQ has a 3-year battery life and data memory that is 20% greater than other monitoring devices.
Robert Robson, CEO of the Royal Navy and Royal Marines Charity, says:
"Medical research is vital for the future development of our Service personnel and we, as the Navy's principal charity, have a mission to support projects like the Dhaulagiri Medical Research Expedition. The venture epitomizes the 'can-do' attitude of our armed forces and will help improve training for personnel in the years to come."
New approach within mountaineering
The BSDMRE expedition will also signify a new approach within military mountaineering. Until now, military attempts on such high mountains have been attempted "siege style."
This usually involves repeatedly carrying loads and establishing camps ever higher on the mountain, often supplemented with bottled oxygen.
Informed by recent research, BSDMRE will instead climb in a lightweight "alpine" style, acclimatizing on Damphus and then Tukuche peaks (6,060 m and 6,900 m, respectively) before making a fast and light weight ascent of Dhaulagiri without oxygen from two intermediate camps over a 5-day period.
Mountaineers of all abilities and ranks are taking part in the expedition, promoting and developing the sport within the military and beyond.
Trekking and development teams will explore trekking circuits and the smaller Tukuche Peak, while the main team will attempt the northeast ridge of Dhaulagiri.
The expedition has the support of influential patrons:
His Royal Highness the Duke of York, Mark Lancaster MP, the Second Sea Lord, Air Member for Personnel, Commandant General Royal Marines and the Surgeon General acting as Patron for the scientific program.