Early results are already suggesting that the human heart may develop on a different timeline from other mammals.
While the tissue in the walls of a pig heart develops a highly organised structure at a relatively early stage of a foetus's development, a paper published in the Journal of the Royal Society Interface Focus reports that the there is little organisation of the human heart's cells until 20 weeks into pregnancy.
A pig's pregnancy lasts about three months and the organised structure of the walls of the heart emerge in the first month of pregnancy. The new study only detected similar organised structures well into the second trimester of the human pregnancy. Human foetuses have a regular heartbeat from about 22 days.
Dr Eleftheria Pervolaraki, Visiting Research Fellow at the University of Leeds' School of Biomedical Sciences, said: "For a heart to be beating effectively, we thought you needed a smoothly changing orientation of the muscle cells through the walls of the heart chambers. Such an organisation is seen in the hearts of all healthy adult mammals.
"Foetal hearts in other mammals such as pigs, which we have been using as models, show such an organisation even early in gestation, with a smooth change in cell orientation going through the heart wall. But what we actually found is that such organisation was not detectable in the human foetus before 20 weeks," she said.
Professor Arun Holden, also from Leeds' School of Biomedical Sciences, added: "The development of the foetal human heart is on a totally different timeline, a slower timeline, from the model that was being used before.
"This upsets our assumptions and raises new questions. Since the wall of the heart is structurally disorganised, we might expect to find arrhythmias, which are a
|Contact: Amy Pullan|
University of Sheffield