<![CDATA[New research claims that the legendary explorer Sir Ernest Henry Shackleton may have suffered from a congenital atrial septal defect - a condition more commonly known as 'a hole in the heart'. Shackleton died of a heart attack in 1922, a few hours after arriving in South Georgia to start an expedition to circumnavigate the Antarctic. He was just 47 years old. Reports of Shackleton's expeditions, often written by other members of his traveling parties, paint a mixed picture of his physical health. He was capable of remarkable acts of strength and endurance, crossing the glaciers and mountains of South Georgia without any health problems. On other expeditions however, he was hit by alarming bouts of breathlessness and weakness, moments of stark contrast to his usual, robust image. These mysterious breakdowns have long been a matter of interest to historians and doctors alike, vital elements of Shackleton's life which could offer an insight into both his achievements and his death. With personal experience of traveling in the harsh South Georgian mountains and glaciers, retired anesthetist and author of the new study Dr. Ian Calder was inspired to attempt a diagnosis of Shackleton's breakdowns. After studying materials held in the Scott Polar Research Institute in Cambridge, Dr. Calder and Dr. Jan Till came to the conclusion that Shackleton had 'suffered' from a hole in the heart. Dr. Calder and Dr. Till's study, titled 'Shackleton's Heart', was published by the Journal of the Royal Society of Medicine last week. Accounts from Shackleton's companions and travel partners were key to making the diagnosis. "The evidence rests in diary entries made by Dr Eric Marshall, the medical officer of Shackleton's second expedition to the Antarctic in 1907-9," said Dr Calder in a press release from Sage Publishing. "The detection and treatment of an atrial septal defect is now reasonably straightforward, but was not available to Shackleton." Born in County Kildare, Ireland in 1874, the most famous adventure of Shackleton's life was his attempt to cross the entire continent of Antarctica in 1914. In early 1915 the crew were forced to abandon their ship 'Endurance' after it became trapped, leaving them no choice but to live on the ice for the next ten months. In April 1916 Shackleton led a team of six men on a small boat across 1,300 km of ocean to a South Georgian whaling station to call for help. In August 1916, the rest of Shackleton's team were rescued, every member of the expedition surviving the ordeal. An atrial septal defect is a hole in the wall that separates the two upper chambers of the heart. Caused by problems when a baby's heart is forming, the hole allows oxygen rich blood to leak into the chamber containing oxygen poor blood. Among the symptoms of the defect are shortness of breath when exercising, fatigue, heart palpitations and skipped beats, and strokes. In the long term a hole in the heart does severe damage to the heart and lungs - greatly increasing the chances of heart failure. Perhaps most surprisingly, the authors claim that Shackleton may have known he had something wrong with his heart, but deliberately avoided examination by doctors out of fear they would attempt to block his expeditions. "Some may feel that Sir Ernest was irresponsible in undertaking the leadership of Antarctic expeditions if he suspected a problem, but to paraphrase Dr Johnson, there is seldom a shortage of prudent people, whilst the great things are done by those who are prepared to take a risk", said Dr. Calder. ]]>