There can be no question that a person has died and still, their heart may flicker. That's one takeaway from a new study analyzing the final moments of 631 patients taken off life support in Canada, the UK, and the Czech Republic. Researchers were particularly interested to learn "the minimum duration of pulselessness required before organ donation after circulatory determination of death," which they say has not been well studied. A person's death is generally called two to five minutes after blood circulation has stopped, per Gizmodo. And at no point in the study was a death determination found to be wrong. But doctors did notice resumed cardiac activity and/or respiratory movement in five patients, or 1% of the study group, after a period of pulselessness. That outcome, it turns out, was more common than they realized.
Analysis of blood-pressure and electrocardiographic waveforms recorded up to 30 minutes after pulselessness revealed 67 instances of resumed cardiac activity among 480 participants, including the five mentioned, for a rate of 14%, according to the study published Thursday in the New England Journal of Medicine. In the most extreme case, cardiac activity resumed 4 minutes and 20 seconds after a pulse was felt. But "no one regained sustained circulation or consciousness," per a release. "Doctors and families should be aware about this happening 14% of the time. But they also should be reassured that it doesn't mean that the person will come back to life," study author Sonny Dhanani tells Gizmodo. Indeed, she hopes the research, partly funded by the Canadian government, will comfort donors who "fear their organs will be taken before they die." (Read more death stories.)