It’s been heart week on Radio 4, celebrating the anniversary of the first ‘successful’ heart transplant in 1967, which was performed, controversially, by Dr Christiaan Barnard in South Africa on a patient called Louis Washkansky (who survived the operation and lived for 18 days). The heart, that mysterious, almost mystical organ, is freighted with such cultural significance that back then there were some who thought such feats of medical skill were tampering dangerously with our humanity.