Polar explorer Ernest Shackleton may have had hole in his heart, doctors say

Researchers claim to find evidence in diary of explorer's doctor that his health problems may have been caused by atrial septal defect

His expeditions into the polar unknown earned him a legacy as one of the most heroic explorers of our time. But studies into the diaries of Ernest Shackleton have led doctors to believe he may have led three British voyages to the Antarctic while suffering health problems caused by a hole in his heart.

In a piece published in the Journal of the Royal Society of Medicine, retired anaesthetist Ian Calder and consultant cardiologist Jan Till said they consulted material held in the Scott Polar Research institute - including personal diaries of Shackleton's doctor - to get to the bottom of the explorer's ailments.