How to Avoid AF (Atrial Fibrillation)

Atrial fibrillation (AF) is an episodic irregular heart rhythm that occurs when the heart’s two upper chambers beat erratically and out of sync with the lower chambers. These then pump the blood rapidly, unevenly, and inefficiently, allowing it to pool and clot in the chambers, increasing the risk of stroke or heart attack. AF affects 3% to 5% of people over 65, and is responsible for about 15% of all strokes. A study was designed by University of Minneapolis physicians to determine how many cases of AF could theoretically be avoided by reducing one or more known risk factors – high blood pressure, smoking, diabetes, overweight, and prior heart disease. The results are published in the online version of Circulation.

Almost 15,000 middle aged men and women were enrolled in the Atherosclerosis Risk in Communities (ARIC) Study. The risk factors (above) were categorized for each subject into optimal, borderline, and elevated levels, and individuals were classified into one of these three groups. During an average follow-up of 17 years, more than 1500 cases of AF were identified. These were most frequent in white men and least frequent in black women.

Overall, 57% of the AF episodes were linked to more than one borderline or elevated risk factor in the individual. Of these risks, high blood pressure was the strongest predictor, accounting for more than 1/5 of all cases. If borderline blood pressures were included, the frequency rose to approximately 1 in 4.

It's clear that a significant proportion of all cases of AF can be avoided if attention is paid to reduction of risk factors to optimal levels, or even borderline levels. This is important since the existence of ‘pre-hypertension’ and ‘pre-diabetes’ have been recognized – conditions that clearly for within the borderline definition, but are often neglected by the patient.