According to Davies, this could provide a scientific explanation for the long-held belief that heart attacks can be triggered by a stress, a sudden shock, or overexertion.
To test this theory they added norepinephrine, at a level that would be found in the body following stress or exertion, to biofilms formed on the inner walls of silicone tubing.
“At least one species of bacteria – Pseudomonas aeruginosa – commonly associated with carotid arteries in our studies, was able to undergo a biofilm dispersion response when exposed to norepinephrine, a hormone responsible for the fight-or-flight response in humans,” said Davies. Because the biofilms are closely bound to arterial plaques, the dispersal of a biofilm could cause the sudden release of the surrounding arterial plaque, triggering a heart attack.
To their knowledge, this is the first direct observation of biofilm bacteria within a carotid arterial plaque deposit, says Davies. This research suggests that bacteria should be considered to be part of the overall pathology of atherosclerosis and management of bacteria within an arterial plaque lesion may be as important as managing cholesterol.