Contribution This systematic review found that radiofrequency ablation after a failed drug course maintained sinus rhythm more often than continuation of drug therapy alone .
The benefits of maintaining sinus rhythm with antiarrhythmic drugs appeared to be offset by the serious adverse effects of the drugs .
Context Is radiofrequency catheter ablation a better alternative than medical therapy for patients with atrial fibrillation ?
The Editors Atrial fibrillation is the most common sustained arrhythmia in clinical practice ( 1 ) .
Its prevalence increases with age , from 0.1 % in people younger than 55 years to more than 9 % by 80 years of age ( 2 ) .
The heavy burden of atrial fibrillation on morbidity , mortality , and health care re sources creates a pressing need for novel approaches to management .
In some patients , adequate pharmacologic slowing of the ventricular response rate ( a rate-control strategy ) is sufficient to control symptoms .
However , many patients remain symptomatic from the lack of organized atrial contraction and the persistent irregularity of the ventricular response in atrial fibrillation .
In such patients , the appropriate treatment is restoration of normal sinus rhythm , achieved electrically or chemically ( a rhythm-control strategy ) ( 2 ) .
Radiofrequency catheter ablation is a promising approach that offers the benefits of maintaining sinus rhythm without the adverse effects of antiarrhythmic drugs .
Catheter ablation for atrial fibrillation is based on the underst and ing that electrical activity emanating from the pulmonary veins frequently serves as a trigger for atrial fibrillation .
In the late 1990s , Hassaguerre and colleagues ( 5 ) observed that elimination of local electrograms at these foci with radiofrequency energy reduced the risk for recurrence of atrial fibrillation .
Currently , the foundation of most atrial fibrillation ablation procedures is to target and electrically isolate the pulmonary veins ( 6 ) .
This may be achieved by delivering lesions immediately outside the ostia of the pulmonary veins or along a wider area in the left atrium encircling the veins .
Additional lesion sets have been used to ablate nonpulmonary vein triggers of atrial fibrillation and to target atrial areas thought to be responsible for maintaining atrial fibrillation ( 6 ) .
These linear lesions may be created in the posterior left atrium , the roof of the left atrium , the interatrial septum , and the isthmus formed between the mitral annulus and the pulmonary vein or left atrial appendage .
At present , the Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation , put forth by the Heart Rhythm Society and endorsed by several professional organizations , states that the foundation of most atrial fibrillation ablation procedures is to target the pulmonary veins , pulmonary vein antra , or both ( 6 ) .
The panel advised us that 8-mmtip and irrigated-tip catheters are now the catheters of choice for radiofrequency ablation of atrial fibrillation in the United States .
The conventional 4-mmtip catheter is rapidly being phased out of use for this indication .
The following 3 key questions were formulated : 1 .
What is the effect of radiofrequency catheter ablation on short-term ( 6 to 12 months ) and long-term ( > 12 months ) rhythm control ; rates of congestive heart failure ; changes in the size of the left atrium and ventricle ; rates of stroke ; quality of life ; avoiding anticoagulation ; and readmissions for paroxysmal , persistent , and long-st and ing persistent ( chronic ) atrial fibrillation ?
2 .
How does the effect of radiofrequency ablation  on rhythm control differ among the various techniques used ?
3 .
What are the short- and long-term complications and harms associated with radiofrequency ablation ?
Changes in Atrial Fibrillation Cycle Length and Inducibility During Catheter Ablation and Their Relation to Outcome
Background —The modification of atrial fibrillation cycle length ( AFCL ) during  catheter ablation in humans has not been evaluated . Methods and Results —Seventy patients undergoing ablation of prolonged episodes of AF were r and omized to pulmonary vein ( PV ) isolation or additional ablation of the mitral isthmus .  Mean AFCL was determined at a distance from the ablated area ( coronary sinus ) at the following intervals : before ablation , after 2- and 4-PV isolations , and after linear ablation . Inducibility of sustained AF ( ≥10 minutes ) was determined before and after ablation . Spontaneous sustained AF ( 715±845 minutes ) was present in 30 patients and induced in 26 ( AFCL , 186±19 ms ) . PV isolation terminated AF in 75 % , with the number of PVs requiring isolation before termination increasing with AF duration ( P = 0.018 ) . PV isolation result ed in progressive or abrupt AFCL prolongation to various extents , depending on the PV : to 214±24 ms ( P < 0.0001 ) when AF terminated and to 194±19 ms ( P < 0.002 ) when AF persisted . The increase in AFCL ( 30±17 versus 14±11 ms ; P = 0.005 ) and the decrease in fragmentation ( 30.0±26.8 % to 10.3±14.5 % ; P < 0.0001 ) were significantly greater in patients with AF termination . Linear ablation prolonged AFCL , with a greater prolongation in patients with AF termination ( 44±13 versus 22±23 ms ; P = 0.08 ) . Sustained AF was noninducible in 57 % after PV isolation and in 77 % after linear ablation . At 7±3 months , 74 % with PV isolation and 83 % with linear ablation were arrhythmia free without antiarrhythmics , which was significantly associated with noninducibility ( P = 0.03 ) with a recurrence rate of 38 % and 13 % in patients with and without inducibility , respectively . Conclusions —AF ablation results in a decline in AF frequency , with a magnitude correlating with termination of AF and prevention of inducibility that is predictive of subsequent clinical outcome
Contribution This systematic review found that radiofrequency ablation after a failed drug course maintained sinus rhythm more often than continuation of drug therapy alone .
The benefits of maintaining sinus rhythm with antiarrhythmic drugs appeared to be offset by the serious adverse effects of the drugs .
Context Is radiofrequency catheter ablation a better alternative than medical therapy for patients with atrial fibrillation ?
The Editors Atrial fibrillation is the most common sustained arrhythmia in clinical practice ( 1 ) .
Its prevalence increases with age , from 0.1 % in people younger than 55 years to more than 9 % by 80 years of age ( 2 ) .
The heavy burden of atrial fibrillation on morbidity , mortality , and health care re sources creates a pressing need for novel approaches to management .
In some patients , adequate pharmacologic slowing of the ventricular response rate ( a rate-control strategy ) is sufficient to control symptoms .
However , many patients remain symptomatic from the lack of organized atrial contraction and the persistent irregularity of the ventricular response in atrial fibrillation .
In such patients , the appropriate treatment is restoration of normal sinus rhythm , achieved electrically or chemically ( a rhythm-control strategy ) ( 2 ) .
Radiofrequency catheter ablation is a promising approach that offers the benefits of maintaining sinus rhythm without the adverse effects of antiarrhythmic drugs .
Catheter ablation for atrial fibrillation is based on the underst and ing that electrical activity emanating from the pulmonary veins frequently serves as a trigger for atrial fibrillation .
In the late 1990s , Hassaguerre and colleagues ( 5 ) observed that elimination of local electrograms at these foci with radiofrequency energy reduced the risk for recurrence of atrial fibrillation .
Currently , the foundation of most atrial fibrillation ablation procedures is to target and electrically isolate the pulmonary veins ( 6 ) .
This may be achieved by delivering lesions immediately outside the ostia of the pulmonary veins or along a wider area in the left atrium encircling the veins .
Additional lesion sets have been used to ablate nonpulmonary vein triggers of atrial fibrillation and to target atrial areas thought to be responsible for maintaining atrial fibrillation ( 6 ) .
These linear lesions may be created in the posterior left atrium , the roof of the left atrium , the interatrial septum , and the isthmus formed between the mitral annulus and the pulmonary vein or left atrial appendage .
At present , the Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation , put forth by the Heart Rhythm Society and endorsed by several professional organizations , states that the foundation of most atrial fibrillation ablation procedures is to target the pulmonary veins , pulmonary vein antra , or both ( 6 ) .
The panel advised us that 8-mmtip and irrigated-tip catheters are now the catheters of choice for radiofrequency ablation of atrial fibrillation in the United States .
The conventional 4-mmtip catheter is rapidly being phased out of use for this indication .
The following 3 key questions were formulated : 1 .
What is the effect of radiofrequency catheter ablation on short-term ( 6 to 12 months ) and long-term ( > 12 months ) rhythm control ; rates of congestive heart failure ; changes in the size of the left atrium and ventricle ; rates of stroke ; quality of life ; avoiding anticoagulation ; and readmissions for paroxysmal , persistent , and long-st and ing persistent ( chronic ) atrial fibrillation ?
2 .
How does the effect of radiofrequency ablation  on rhythm control differ among the various techniques used ?
3 .
What are the short- and long-term complications and harms associated with radiofrequency ablation ?