Tuesday, September 09, 2008


Chronic atrial fibrillation ( A.Fib. ), is the most common arrhythmia, especially in the older age group ( above 70 years ). There has been much progress in the management of A.Fib. principally because chronic A.Fib. is a common cause of the dreaded cardio-embolic Stroke. When I was in medical school, we only had drugs to control A.Fib. rate and occasionally we tried drugs or cardioversion, to try and restore sinus rhythm. This is still done, even till this day. In the 90s, much work was done to try and elucidate the arrhythmia pathways of A.Fib.. This began the era of A.Fib ablation surgery. The MAZE procedure still have their proponents, even till this day. The MAZE procedure is an attempt by the cardiac surgeons to surgical cut-up the atrium, in an attempt to surgically interrupt the A.Fib. tracts. This proved very invasive and the results were at best modest. The interventionist then got into the scene, with the advent of advance electrophysiological techniques, to use EPS to map out the A.Fib tracts, many of which seem to origin and congregate around the pulmonary veins. They were then able to ablate these A.Fib tracts. The electrophysiologist, having had great experience with SVT and even VT ablation, were very comfortable moving their hot wires all over the cardiac chambers, burning here and burning there. A.Fib ablation benefitted from their great skill and was obviously less invasive and seem to have reasonable immediate results. The A.Fib can still recur and often, AAD ( anti-arrhythmic drugs ) are still required, post-ablation, to maintain sinus rhythm. Pulmonary Vein ablation also have their fair share of complications, especially in less experience hands. With the advent of ablative therapy for A.Fib., cardiologist treating A.Fib. were divided into two groups. Those who will use drugs to control HR and anti-coagulate to prevent stokes and those who would aggressively seek to convert all A.Fib into sinus rhythm, including the use of AAD and Pulmonary Vein ablation.
One of the drug that had been in use for control of A.Fib is Amiodarone. This is a good drug, except that the side effects are also many and troublesome. Chronic pulmonary fibrosis and chronic thyroid disease is no simple side-effects. Chronic use of Amiodarone for A.Fib is just exchanging one disease state for another potentially more troublesome disease state. That is obviously not acceptable. Sanofi-Aventis has recently unveil a new generation Class 3 AAD called "Dronedarone " for the chronic control of A.Fib. The recent EURIDIS, ADONIS and ATHENA studies presented at the recent "Heart Rhythm Society ( HRS )" meeting, showed that dronedarone, was safe and able to reduced hospitalisation from A.Fib and A.Fib related complications and also death from cardiac arrhythmias. The safety profile of dronedarone was obviously better than amiodarone with no effects on the lungs and thyroid.
One of the surprises of the HRS meeting was the presentation of the results of a subset analysis from the HERS study, showing that the use of statins may be associated with a reduce incidence of A.Fib, especially in females, in the older age group. This further lends weight to the argument that A.Fib may also have an inflammatory basis, as statins have many properties, including its effect as an anti-inflammatory agent.

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