The cardiac natriuretic peptides (CNP) have been shown to be of value in the diagnosis, prognosis, treatment and monitoring of heart failure.1-4 There have been studies showing an increase in BNP and NT-proBNP due to exercise in non-ischaemic5 and ischaemic individuals.6-12 This increase was greater in patients with myocardial ischaemia. This evidence concerns the gene CNP and heart failure.