Stroke risk high from heart disease

Australians are being warned of a higher risk of stroke caused by the nation’s most common heart rhythm disorder, atrial fibrillation (AF).

AF is the most common irregular heartbeat. Chest pain, a ‘racing’ or unusual heartbeat and shortness of breath are all symptoms of the condition, which is responsible for an increasing number of hospital admissions in Australia.

The prevalence of atrial fibrillation reportedly increases with age, with 8% of people aged over 80 years reportedly living with the condition.

Cardiology researchers at the University of Adelaide are led by Professor of Cardiology, Prash Sanders, who is based at the Centre of Heart Rhythm Disorders at the University and the Royal Adelaide Hospital.

Among the researchers in his team is University of Adelaide PhD student, Carlee Schultz, who is investigating the mechanisms in AF that cause blood clots and therefore stroke.

“It is still not widely understood in the community that patients with atrial fibrillation are at five times greater risk of stroke, because of clots that form within the heart,” Ms Schultz says.

“The abnormal beating of the heart associated with AF causes an unusual swirling of blood. This blood pools in the atrium, where blood clots can form.”

Ms Schultz is studying samples taken from 150 patients, 100 of them from South Australia with and without atrial fibrillation, and 50 with another heart disease, from a collaborating hospital in India.

“My research is aimed at finding out what is happening to the blood in the heart. So far, these studies are giving us a much better picture of how the blood clots are caused – how and why platelets are being activated in the blood, how that affects the vascular tissue around the heart, and what kinds of inflammation it causes,” Ms Schultz says.

The research teams are hoping to find markers for blood clot formation so that we can better understand when a stroke might occur, as well as looking for the precursors of AF so that the condition might one day be prevented altogether.

“Added to this is the personal and emotional cost to patients and loved ones, which means it is a major issue for the population. We hope that our research efforts will make a significant contribution to the understanding of and, eventually, the treatment of atrial fibrillation, which will help to prevent stroke,” Professor Sanders says.

Up to 40% of strokes in Australia are directly linked with atrial fibrillation. In 2009 alone, the cost of stroke in Australia was $2 billion.