Catheter Ablation of Atrial Fibrillation: Who? How? How Good? John D. Day, M.D. Director, Utah Cardiovascular Research Institute Utah Heart Clinic Arrhythmia Service LDS Hospital *Disclosure: No conflicts of interest, no relationships to disclose*

Atrial Fibrillation: Magnitude of the Problem 15-30% of all strokes from atrial fibrillation Heart failure risk increased with atrial fibrillation 2.5x mortality increase with atrial fibrillation (Framingham data) 1 in 4 people age 40 will develop Afib No effective or safe medications for atrial fibrillation Anti-arrhythmics may increase mortality or expose patient to significant toxicities Increasing risk factors: age, hypertension, heart failure JACC 2003;41: , Circulation 2004;110:

Ablation of Atrial Fibrillation 1.Mechanisms of Atrial Fibrillation 2.Historical Approach to Catheter Ablation of Atrial Fibrillation 3.Our Approach to Catheter Ablation of Atrial Fibrillation 4.Future Directions

Mechanism: Wavelet Hypothesis Multiple wavelets – Moe and Abildskov 1959 “Multiple independent reentrant wavelets are necessary to maintain fibrillation. These wavelets are always changing in position, shape, size and number with each successive excitation” Confirmed by animal/human mapping techniques Moe, Am Heart J; 1959

Results 94% of atrial fibrillation triggers (premature atrial beats) arise from pulmonary veins Pulmonary Veins as source of atrial fibrillation (Winterberg, 1906) New England Journal of Medicine 1998;339; RA LA

Why the Pulmonary Veins? Myocardial Tissue Lines the Pulmonary Veins Pulmonary vein lumen Left Atrium

Pulmonary Vein Isolation 1998-Present Electrical isolation of pulmonary vein triggers (premature atrial beats) Success: 50-90% Increased success without pulmonary vein stenosis by isolating outside of vein (antrum) Evolution of Technique –Focal –Circumferential –Segmental –Antrum isolation

Mapping of Atrial Fibrillation Trigger to Left Upper Pulmonary Vein

Sinus rhythm by EKG Atrial fibrillation in pulmonary vein by Lasso catheter A A A A A A A A A A A A AA A A V Sinus rhythm by left atrial recordings from coronary sinus A V Electrical Isolation of Pulmonary Vein

J Cardiovasc Electrophysiol 2003;14: Limitations of Pulmonary Vein Isolation: Pulmonary Vein Stenosis Before AblationAfter Ablation >50% reduction in ostium of left superior pulmonary vein

2003: Wavelets and Pulmonary Vein Triggers Both Important Moe, Am Heart J; 1959

Convergence of Techniques: Pulmonary Vein Isolation and Left Atrial Substrate Modification: 2003-Present Isolation of pulmonary veins (triggers) and modification of substrate both important (wavelet mechanism) New technique: left atrial ablation, wide area circumferential ablation, circumferential left atrial pulmonary vein ablation (Pappone, Morady, and others) Increased success by isolating/encircling outside of the pulmonary veins (pulmonary vein stenosis eliminated) Ongoing issue: Electrical isolation of pulmonary veins by Lasso catheter or anatomic lesion set with pulmonary vein conduction delay (no Lasso  voltage reduction)

Circulation 2003;108: , Journal of the American College of Cardiology 2005;46: Ablation lesion Set Proposed by Morady in 2003 (based on Pappone approach): Anatomic ablation lesion set Success rate similar if pulmonary veins isolated by Lasso catheter versus voltage reduction with an anatomic approach (Lasso not used)

2004: Targeting Autonomic Inputs/Fractionated Electrograms

Location of the Left Atrial Ganglionic Plexi Heart Rhythm 2005;2:S11

Autonomic/Fractionated Electrogram Approach Journal of the American College of Cardiology 2004;43: Lesion sets similar to the wide area pulmonary vein circumerferential ablation approach!!!

New Paradigm for Atrial Fibrillation Pulmonary Vein and Autonomic Triggers Multiple Wavelets Electrical Remodeling Substrate Atrial Size Fibrosis Stretch Drugs In progression to persistent and permanent atrial fibrillation triggers become less important

Mortality and Morbidity with Atrial Fibrillation Ablation 1,171 consecutive patients referred for ablation in Milan, Italy (January 1998  March 2001) 589 ablated versus 582 drug treated (1/3 amiodarone, 1/3 class Ic, 1/3 sotalol/class Ia) End-points: mortality, morbidity (heart failure/stroke), & quality of life (900 day follow-up) Journal of the American College of Cardiology 2003;42:

Pappone Approach Each pulmonary vein encircled (voltage reduction) 2 Posterior wall ablation lines Mitral valve flutter ablation line Right atrial cavo- tricuspid isthmus flutter line

Ablation versus Drug Success Journal of the American College of Cardiology 2003;42: % 37%

Mortality After AF Ablation Journal of the American College of Cardiology 2003;42: Mortality After AF Ablation = Expected for Italian Population 54% Mortality Reduction with Ablation versus Drug Atrial Fibrillation mortality on Drug Less than Expected Italian Mortality

Morbidity After AF Ablation Journal of the American College of Cardiology 2003;42: hello p< % reduction in heart failure or stroke at 3 years in ablated patients versus drug treated patients

Our Current Approach: 3D CT and CARTO Electroanatomic Imaging

Our Results: LDS Hospital 49 consecutive patients age 59±11 (Jan 1, 2004 – October 1, 2004—now 300+) 7±3 months follow-up Drug refractory symptomatic atrial fibrillation (failed 2.3 ± 1.2 anti-arrhythmic drugs) 36 paroxysmal and 13 persistent atrial fibrillation LA size: 48 ± 8 mm, 16 with structural heart disease Follow-up: Pacemaker/ICD logs, Holter, event monitor Approach: Encircle pulmonary veins (end-point of voltage reduction), roof and mitral line, target autonomics and complex fractionated electrograms 12 th World Congress of Cardiology, Vancouver 2005

Atrial Fibrillation Ablation Results: LDS Hospital n=49 12 th World Congress of Cardiology, Vancouver 2005

Complications 300+ cases now performed utilizing this technique ( ) No strokes 3 pericardial effusions requiring pericardiocentesis (1%, experience related) 1 atrio-esophageal fistula* 1 esophageal perforation* –Successful temporary esophageal stenting –No long-term problems *Early in experience before ultrasound monitoring 12 th International Congress of Cardiology, Vancouver 2005

New Achilles Heel: Potential Esophageal Injury Posterior LA Wall Esophagus

Our Approach to Minimize Esophageal Risk: Intracardiac Echo Monitoring During Radiofrequency Delivery and Esophageal Temperature Probes

Future Directions: Ultrasound/Cryo Isolation of Pulmonary Veins? Problem: “One size doesn’t fit all”

Robotic Approach to Ablations? Stereotaxis Magnetic Navigation? Journal of the American College of Cardiology 2003;42:

As most strokes from atrial fibrillation arise from the left atrial appendage…Closure after ablation?

Final Points Who? –Ideal patient: Young, paroxysmal atrial fibrillation with no structural heart disease –Success rate lower with permanent atrial fibrillation and structural heart disease How?  3 main “techniques” –All 3 with similar ablation lesion sets –Pulmonary vein isolation, wide area circumferential ablation, Autonomic/fractionated electrograms –Our approach: Integration of all 3 techniques How Good? –80-90% success rate in experienced hands with any technique