The investigators specifically studied the length of time between two points on the electrocardiogram read-out known as the ‘PR interval’, which is associated with a number of common electrical disorders such as atrial fibrillation and other arrhythmias.

The findings, published in the journal Nature Communications, report 202 locations in the genome with links to this type of electrical activity in the heart—141 of which had not been previously identified. This more than triples the number of known genetic regions linked to this type of electrical activity and explains about 62 percent of its heritability.

Co-lead researcher Professor Patricia Munroe from Queen Mary’s William Harvey Research Institute said: “This is the largest global study of its kind to investigate the genetic basis of the PR interval - a well-established electrocardiogram risk marker for heart disease and mortality. The insights provide new knowledge on biological processes relating to the heart's electrical activity and potential avenues of drug research for preventing and treating heart conditions.”

Steven Lubitz from Massachusetts General Hospital and the Broad Institute added: "That’s really a striking discovery that wouldn’t have been possible a few years ago. But thanks to many studies, including the UK Biobank, we now have all this imaging and electrocardiogram data paired with genetic data, which has proven to be a really powerful combination.”

The findings indicate that an individual's inherited predisposition to heart disease is not the result of single-gene mutations, but rather a cumulative effect of many variants across the genome.

The study was funded in part by the Medical Research Council, NIHR Barts Biomedical Research Centre, National Institutes of Health and the American Heart Association.