THERAPUETIC OPTIONS FOR AFIB: CATHETER ABLATION SAMBIT MONDAL, MD CARDIAC ELECTROPHYSIOLOGIST

AFLUTTER REVISITED AFLUTTER - RIGHT ATRIAL PRIMARILY AFIB - LEFT ATRIAL PRIMARILY

CLASSIFICATION Paroxysmal recurrent - at least 2 episodes terminates spontaneously within 1wk Persistent doesn’t terminate within 1wk or requires cardioversion to convert within 1wk Permanent / chronic > 1yr duration

> 2.2 MILLION in USA have AFIB

AFFIRM TRIAL RACE TRIAL N Engl J Med 2002; 347: and , Dec 5,2002 RATE VS RHYTHM CONTROL

AFFIRM- efficacy of antiarrhythmics

AFFIRM TRIAL 3/4 normal EF Mortality difference mainly due to non- cardiovascular and cancer deaths No difference in the rate of cardiovascular events - including stroke. Presence of sinus rhythm reduced mortality significantly, however anti-arrhythmics seemed to increase mortality by 49% : beneficial effects of SR may be offset by anti-arrhythmics DIAMOND study confirmed the above hypothesis.

OPTIONS FOR RATE CONTROL MEDICATIONS AV NODAL ABLATION last option doesn’t eliminate symptoms of afib permanent dependancy on PM 6.3% 1-yr mortality : 2% risk of SCD BiV vs single chamber pacing ( PAVE )

so which is better ?rhythm or rate control

PROVEN DATA independent predictor of mortality valvular heart disease post CABG heart failure decrease survival

RHYTHM CONTROL quality of life improved significantly with rhythm mortality data not available stroke risk data pending long term studies progression to heart failure decreased by rhythm control hospital admission / overall cost reduced by rhythm control

NATURAL HISTORY paroyxsmal lone fib perst/perm 50% 40% CATH ABLATION SINUS RHYTHM Heart rhythm Pappone et al. Nov 08:5:11:

RACE FOR A CURE THE HOLY GRAIL

PATHOPHYSIOLOG Y multiple wavelet theory Moe et al. 1980’s multiple reentrant circuits which requires critical mass of atrial tissue to sustain itself basis for cut and sew Cox-Maze procedure to reduce critical mass version I, II and now III atrial transport function difficult to perform - didn’t gain popularity

2003/2004 Pappone et al.

PATHOPHYSIOLOG Y cardiac autonomic nervous system and its relationship with triggered spontaneous electrical firing - Jackman et al. current understanding of triggers, rotors, substrate and autonomic interactions

PATHOPHYSIOLOG Y atrial muscle sleeve into the pulmonary veins as trigger sites APD and ERP within the pulmonary veins shorter than LA tissue slower conduction of tissue towards atrio-pulmonary junction leading to variable block and micro re-entry. areas of slower conduction marked as fractionated potentials more fractionation seen with increased in LA pressures

PATHOPHYSIOLOG Y areas of micro-reentry at the sites of slowed conduction : rotors at LA-PV not clear what causes triggered activity within pulmonary veins atrial remodelling : “afib begets afib” LA-RA electrical heterogeneity and gradient

PATHOPHYSIOLOG Y spectral analysis : dominant frequency stimulation sites within pulmonary veins in paroxysmal afib. chronic afib: no dominant frequency seen. chronic afib: atrial remodelling plays a more dominant role

PATHOPHYSIOLOG Y nearly 1/3 paroxysmal ( unselected population) : non PV triggers non PV triggers : post LA, fossa ovalis, SVC, crista terminalis, ligament of Marshall, AV junction, coronary sinus 4% SVT initiating Afib : AVNRT, AVRT

PAROXYSMAL AFIBPERSISTENT / CHRONIC AFIB antiarrhythmicscardioversion with antiarrhythmics feel better in SRno difference rhythm control rhythm control with meds only and if not possible then RATE CONTROL recurrence

RHYTHM CONTROL SCHEMA ACC/AHA/HRS GUIDELINE UPDATE FOR MANAGEMENT OF AFIB 2006

ANTICOAGULATION CHADS 2 RISK SCORE: Congestive heart failure Hypertension Age greater than 75 Diabetes Mellitus Stroke or any thromboembolic phenomenon CHADS SCORE 0 - ASA 1- ASA OR COUMADIN >1 or high risk markers COUMADIN

ABLATIVE OPTIONS CATHETER BASED SURGICAL - CONCOMITANT SURGICAL STAND ALONE “MINI MAZE”

INDICATIONS SYMPTOMS FAILED ≥ 1 ANTIARRHYTHMIC EF >40% AGE < 80 YRS

SYMPTOMS fatigue “sleeps off as soon as lay on the couch in the evenings” - under- recognized dyspnea on exertion palpitations “heart skipping” chest pain “just don’t feel right”

CATHETER ABLATION It is not a substitute for coumadin therapy and to attempt ablation aiming primarily at stopping coumadin therapy is INAPPROPRIATE All patients will continue coumadin therapy post ablation IT IS NOT A CURE, BUT A TREATMENT APPROACH - much akin to CAD/stent. applies to surgical ablation also

SUCCESS RATES PAROXYSMAL AFIB : > 70-80% PERSISTENT AFIB : >60-70% CHRONIC AFIB : 50-60% SUCCESS AT 6MONTHS POST PROCEDURE RECURRENCE OF ARRHYTHMIA IS COMMON AND NOT A SIGN OF FAILURE - atrial remodelling 3months

CFAE MAPS complex fractionated atrial electrogram V, >120ms represent areas of slow conduction / micro-reentry correlate with epicardial ganglionic plexi important in persistent and chronic cases

ICE intracardiac echo imaging MHz, depth 2-12mm transeptal puncture, defining LA structures, pulmonary vein anatomy, location of circular catheter, complication detection and management

POST ABLATION follow up 2wk - 12 lead EKG 1month - 24 hour holter 3months - 1 month AFib monitor ( decision to take off antiarrythmics) 6month - 1 month Afib monitor ( decision to take off coumadin if CHADS score <2)

RECURRENCE recurrences of atrial fibrillation / atrial tachycardia / left atrial or right atrial flutter recurrences more common within the 1-3month period inflammatory / stimulating effect of thermal injury imbalance of autonomic nervous system delayed effect of growth and maturation of lesions factors favoring recurrences age BMI paroxysmal vs persistent vs chronic size of left atrium structural heart disease

RECURRENCE reconnection PV-LA additional triggers macro-reentrant tachycardia autonomic influences

COMPLICATION cardiac tamponade - upto 3% pulmonary vein stenosis - 1-3% chest pain / dyspnea / recurrent lung infection / pulmonary hypertension atrio-esophageal fistula % fever / chills / hemoptysis / recurrent neurological events phrenic nerve injury - <0.5% hiccups / dyspnea / atelectasis / pleural effusion / cough / thoracic pain Thromboembolic events / air embolism / stroke vascular complication acute coronary occlusion peri-esophageal vagal injury - pyloric spasm / gastric hypomotility fluroscopy related injury mitral valve entrapment of circular catheter

SURGICAL ABLATION

COX MAZE James Cox 1987 extensive cut and sew to interrupt the reentrant circuits technically challenging and time taking long term success rates good however few CT surgeon willing to perform the full cut and sew Maze numerous iteration have been developed. Final version Cox Maze III. linear lines of ablation developed with unipolar sources of energy

ENERGY SOURCES unipolar energy source microwave / radiofrequency / HIFU / cryo / laser bipolar energy source radiofrequency

SURGICAL ABLATION full Cox Maze procedure ( Maze III ) LA ablation sets pulmonary vein isolation

SURGICAL ABLATION INDICATIONS: concomitant procedure - both symptomatic and asymptomatic patients stand alone minimally invasive ( mini Maze) prefer surgical approach failed one or more attempts at catheter ablation not candidates for catheter ablation

Mini - Maze

multi-speciality approach primary care physicians cardiologist cardiac electrophysiologist cardio-thoracic surgeons

“Watchman” left atrial occluding device Maisel W. N Engl J Med 2009; /NEJMp