Medics are already aware that the enlargement of the heart (in the region of the upper left chamber) can be a sign of an increased risk of stroke. To add to these signs medical scientists from Johns Hopkins University have used computational models to examine the alterations to blood flow. The researchers think they can make predictions as to whether the heart is more or less prone to clot formation hence a person suffering from a stroke.
The computer model is based on the science of computational fluid dynamics. This involves using computers to study and solve problems in relation to fluid flows. The technique can be applied to factory sewage outlets and air distribution, as well as a viscous fluid like blood.
With blood, the medics have focused on the path that blood takes as it moves through the heart’s upper left chamber. The model was drawn up after examining two patients with atrial fibrillation. One patient, a woman aged 58, had a healthy heart; the other, a man of 68 years, had an enlarged heart. Both hearts were subjected to analysis.
The examination revealed that the blood from the diseased heart flowed differently compared to the flow of blood from the healthy heart. The diseased heart blood flow took the form of eddies, as what might behave around a stream containing rocks. Applying this learning to the computer program allowed a predictive model to be built.
The model will, according to one of the lead researchers, Dr. Hiroshi Ashikaga, allow doctors to see “exactly how this would increase the risk of developing a blood clot.”
Dr. Ashikaga explains this further to Laboratory Roots: “The vortexes helped move the blood efficiently through the atrium quicker and with less contact with the atrium’s surface tissue”; however, on reaching the top of the atrium, the blood “fell in sheets that coat the surface of the heart.” The slowing down of blood at this stage leads to an enhanced risk of clot formation.
It is hoped the fluid dynamics model will enable medics to examine patients sufficiently early and to make more accurate predictions about those who are at risk from developing strokes.
The research findings are published in the journal Annals of Biomedical Engineering. The paper is headed “A Computational Framework for Personalized Blood Flow Analysis in the Human Left Atrium.”
