%0 Journal Article
%T Chronic Atrial Fibrillation - Chronic Atrial Fibrillation - Open Access Pub
%A Joel Lardizabal
%A Sanjiv Sharma
%J OAP | Home | Journal of Hypertension and Cardiology | Open Access Pub
%D 2017
%X DOI10.14302/issn.2329-9487.jhc-12-edt1 Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function. It is an important risk factor for stroke, and is associated with adverse mortality, morbidity, and healthcare cost outcomes. AF was probably first described in 1906 by Cushny and Edmunds in their article ¡°paroxysmal irregularity of the heart and auricular fibrillation¡±. In their study, they noticed that the atria of anesthetized open-chest dogs were sometimes dilated, with the atrial walls in a state of fibrillatory contraction on myography. That same year, Einthoven published the first electrocardiographic tracing of AF which he termed ¡°pulsus inequalis et irregularis¡± 1, 2. As the most common clinically significant cardiac arrhythmia, chronic AF afflicts over 2.3 million adults in the Unites States, a figure projected to increase to 5.6 million by year 2050. AF has a prevalence of about 1% in the general population. Prevalence increases with age, from 0.1% in those 50 years or younger, to 9% among those 80 years or older 3. The prevalence of AF among those aged 65 or older is also rising with time, from 3% in 1992 to 6% in 2002 4. In the Framingham Study, non-valvular AF was associated with a five-fold increase in the risk of ischemic stroke compared with controls. An even more substantial 17-fold increase in stroke risk exists in patients with AF and rheumatic heart disease 5, 6. The rate of ischemic stroke among elderly patients with AF that were not treated with anticoagulation is around 5% per year. AF is associated with 470,000 hospitalizations and nearly 80,000 deaths annually in the United States alone 7. In a study of Medicare patients aged 65 or older with AF and cardiovascular disease, the 3-year mortality rate ranges from 34¨C71% (higher in males and in older age groups), which is 30% higher than those without AF. The presence of AF also raises hospital costs, with around 9 to 22-fold greater adjusted total spending in 1 year8. The mechanisms for arrhythmogenesis in AF is still not completely understood. Current literature supports 2 prevailing theories, the ¡°multiple wavelet hypothesis¡± and the ¡°automatic focus theory¡±. These mechanisms are not mutually exclusive, and both may occur in the same patient. The first theory holds that AF consists of multiple wavelets of functional re-entry. Small reentrant circuits are constantly arising in the atria, colliding, combining or dividing, thereby spawning daughter wavelets that perpetuate
%U https://www.openaccesspub.org/jhc/article/38