May 18, 2009

Heart dysfunction in runners temporary

Cardiac abnormalities in some marathon runners following competition are temporary, and do not result in damage to the heart muscle, Canadian researchers say.

Researchers at the University of Manitoba say the study involved the first use of cardiac magnetic resonance imaging in a post-marathon setting.

The study examined the cardiac health of 14 runners who participated in the full 2008 Manitoba Marathon in Winnipeg. All runners were classified, for purposes of the study, as non-elite, meaning they participated on a casual, non-professional basis, with limited or no training.

Prior to the marathon, each study participant underwent a comprehensive health screening, including blood tests to determine the levels of cardiac biomarkers, factors present in the blood that reflect the health of the heart muscle.

Study investigator Dr. Davinder S. Jassal St. Boniface General Hospital Research Centre in Winnipeg says that following the race, additional blood samples were taken and echocardiograms and CMR were performed.

In the study, echocardiograms and CMR performed immediately after competition revealed abnormalities, including irregularities in diastolic filling on both sides of the heart and a decrease from 64 percent to 43 percent in the pumping function of the right ventricle.

Although the cardiac biomarkers were elevated post marathon, there was no evidence of direct permanent injury to the heart muscle on CMR imaging, the study says.

The study was presented at the 105th International Conference of the American Thoracic Society in San Diego.