Atrial Fibrillation
By: Allie McCarthy
What is it?
Also known as AF or A-Fib, atrial fibrillation is the most common type of arrhythmia. Arrhythmia is when the rate or rhythm of the heart beat beats too fast or too slow. AF occurs when the heart beats too fast and disorganized electrical signals causes the atria to fibrillate or contract too fast. Blood pools in the atria and the upper and lower chambers do not work as they should.
What are the causes?
Incidence
"Estimates and projections of diagnosed incidence and prevalence of atrial fibrillation (AF) in the United States have been highly inconsistent across published studies. Although it is generally acknowledged that AF incidence and prevalence are increasing due to growing numbers of older people in the U.S. population, estimates of the rate of expected growth have varied widely. Reasons for these variations include differences in study design, covered time period, birth cohort, and temporal effects, as well as improvements in AF diagnosis due to increased use of diagnostic tools and health care awareness. A large health insurance claims database for the years 2001 to 2008, representing a geographically diverse 5% of the U.S. population, was used in this study. The trend and growth rate in AF incidence and prevalence was projected by a dynamic age-period cohort simulation progression model that included all diagnosed AF cases in future prevalence projections regardless of follow-up treatment, as well as those cases expected to be chronic in nature. Results from the model showed that AF incidence will double, from 1.2 million cases in 2010 to 2.6 million cases in 2030. Given this increase in incidence, AF prevalence is projected to increase from 5.2 million in 2010 to 12.1 million cases in 2030. The effect of uncertainty in model parameters was explored in deterministic and probabilistic sensitivity analyses. Variability in future trends in AF incidence and recurrence rates has the greatest impact on the projected estimates of chronic AF prevalence. It can be concluded that both incidence and prevalence of AF are likely to rise from 2010 to 2030, but there exists a wide range of uncertainty around the magnitude of future trends." (http://www.ncbi.nlm.nih.gov/pubmed/23831166)
Risk Factors
- Older than 60 years of age
- Diabetes
- High Blood Pressure
- Coronary artery disease
- Prior heart attacks
- Congestive heart failure
- Structural heart disease (valve problems or congenital defects)
- Prior open-heart surgery
- Untreated atrial flutter (another type of abnormal heart rhythm)
- Thyroid disease
- Chronic lung disease
- Sleep apnea
- Excessive alcohol or stimulant use
- Serious illness or infection
Treatment Options
- Preventing blood clots from forming, thus lowering the risk of stroke.
- Controlling how many times a minute the ventricles contract. This is called rate control. Rate control is important because it allows the ventricles enough time to completely fill with blood. With this approach, the abnormal heart rhythm continues, but you feel better and have fewer symptoms.
- Restoring a normal heart rhythm. This is called rhythm control. Rhythm control allows the atria and ventricles to work together to efficiently pump blood to the body.
- Treating any underlying disorder that's causing or raising the risk of AF—for example, hyperthyroidism (too much thyroid hormone).
http://www.nhlbi.nih.gov/health/health-topics/topics/af/treatment