Understanding the increased risk of atrial fibrillation in athletes: a case-control study.

The study will be a case-control study recruiting athletes with and without atrial fibrillation (AF) to phenotype them to look at structural and electrical differences in athletes with and without AF. Athletes are at a 2.4-fold increased risk of developing AF but the mechanisms behind this are not fully understood. The research area is important because athletes with AF pose an increased risk of stroke. AF is characterised by an irregularly fast heart rhythm causing the atria in the heart to contract spontaneously. Sport and exercise are good for the heart and overall health, but at the extreme end in endurance athletes, it appears too much may be bad, increasing the risk of AF. Male and female athletes from any sport over the age of 18 who have previously competed in competitions will be eligible with a history of AF, and no history of AF for athletic controls. The study will involve a single visit to Glenfield Hospital and the study visit will last approximately 4 hours. The participants will undergo venepuncture, electrocardiogram recording, electronic stethoscope recording, CardioSignal recording to measure cardiac motion, echocardiogram, exercise testing, be fitted with a continuous ECG recorder for 72hrs, and a subset to receive heart MRI. All methods are non-invasive, and the study is a case-control study involving no intervention.