Pacing for atrial fibrillation

Epidemiological data from the Framingham heart study indicate that the cumulative incidence of atrial fibrillation (AF) over a 22 year follow up was 2.1% in men and 1.7% in women. The prevalence of AF increases with age, doubling with each successive decade, and 70% of people with AF are between 65–85 years old. AF is associated with a three- to fivefold increased risk of stroke, a threefold increased risk of congestive heart failure, and a significant 1.5- to 1.9-fold mortality risk even after adjusting for underlying cardiovascular conditions. Pacemaker follow up physicians often have to deal with AF as a co-morbidity. AF may also be associated with brady–tachy syndrome. A high incidence of AF will be present when we use pacemaker therapy after atrioventicular (AV) nodal ablation for medically refractory AF. Conventional pharmacological treatments includes rate control with AV nodal blockers, maintenance of sinus rhythm, and anticoagulation. While rate control and anticoagulation is a recognised treatment strategy, proarrhythmia using class I antiarrhythmic agents to maintain sinus rhythm remains a concern. A recent study1 has shown that low dose amiodarone, when compared to either sotalol or propafenone, is more efficacious in maintaining sinus rhythm. However, amiodarone had to be discontinued for cardiac and non-cardiac side effects in 18% of patients, while 35% of patients still developed AF at 16 months. While newer antiarrhythmic agents may enhance our success in these refractory cases, the current experience underscores the difficulties of long term pharmacological treatment to maintain sinus rhythm. Indeed, the preliminary results of the AFFIRM (atrial fibrillation following investigation of rhythm management) trial did not show the superiority of rhythm maintenance using drugs over rate control alone (late breaking news, American College of Cardiology annual meeting, 2002). Thus, the use of pacing, either alone or in a hybrid fashion with other …