Risk Factors of Atrial Fibrillation

Modifiable

1. Increasing body mass index

- Obesity has reached epidemic proportions in US (nearly 65%). At the meantime, AF cases

reaches the same epidemic proportions. Hence, it is thought to be important contributors to

the development of AF among obese individuals

- A 4% increase in AF risk per 1 unit increase in BMI was observed in men. Obese men had a 52% increased risk for AF, while obese women had a 46% increased risk, compared with those with a normal BMI.

2. Alcohol consumption

- 45% higher among heavy drinkers than abstainers (Known as holiday heart syndrome)

3. Hyperthyroidism

4. Coronary bypass surgery (Atrial fibrillation occurs in one-third of patients)

Valvular surgery (Occurs in more than half)

5. Hypertension*

6. MI*

7. Diabetes*

8. Heart failure*

9. Valvular heart disease*

10. Increasing left atrial size*

Non-modifiable

1. Advancing age

- 0.1 percent in adults younger than 55 years of age to 17.8 percent in those aged 85 years or

older

2. Male sex

- At age 40 the lifetime risk is approximately 26 percent for men and 23 percent for women

and by 80 years of age declines only to 23 percent and 21 percent, respectively

- The Rotterdam Study - similar lifetime risk of atrial fibrillation in those 55 to 59

years (24 percent in men, 22 percent in women), but at 80 years of age the reported lifetime

risk was lower (16 percent in men, 15 percent in women)

3. Family history of heart disease

- Thirty to 40% of those with AF, especially those at a young age, have at least one parent

with AF and genes associated with the sodium channel, the potassium channel and gap

junction proteins have been implied)

4. Congenital heart disorders - Heart problems present at birth (Heart's chambers or valve)

- Gene defects linked to chromosome 10,6,5 and 4 have been associated with familial AF)

* Termed upstream risk factors. It is not fully understood. Catecholamine excess, hemodynamic stress, atrial ischemia, atrial inflammation, metabolic stress, and neurohumoral cascade activation are all purported to promote atrial fibrillation.

References:

1. K. Parven & C. Michael (eds.) 2009, Kumar & Clark's Clinical Medicine Seventh Edition

2. http://docnews.diabetesjournals.org/content/2/4/12.1.full...For full article, go to:

Wang TJ, Parise H, Levy D, et al.: Obesity and the risk of new-onset atrial fibrillation. JAMA 292: 2471–2477, 2004

3. http://www.medicalnewstoday.com/articles/30592.php

4. Hurst's The Heart, 12e:

Eds. Valentin Fuster, Robert A. O'Rourke, Richard A. Walsh, Philip Poole-Wilson

Chapter 2 Burden of Increasing Worldwide Cardiovascular Disease