A century after expedition to Antarctica, Shackleton diagnosed with 'hole in the heart'

Historians have pondered the cause of Shackleton's physical breakdowns. Inspired by his own experience of crossing South Georgia in a party led by mountaineer Stephen Venables, retired anaesthetist Dr Ian Calder, with consultant cardiologist Dr Jan Till, made use of material held in the Scott Polar Research Institute in Cambridge to diagnose an atrial septal defect (hole in the heart).

"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. "The detection and treatment of an atrial septal defect is now reasonably straightforward, but was not available to Shackleton."

The authors believe that Shackleton knew he had something wrong with his heart because he avoided being examined by doctors who might have tried to prevent him going to Antarctica.

Dr Calder comments: "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."

Shackleton died of a heart attack in 1922, a few hours after arriving in South Georgia at the beginning of his fourth expedition. He was 47 years of age.