2015 Atrial Fibrillation Therapy Meds, Shock, or Ablate? D. Scott Kirby MD, FACC Cardiac Electrophysiologist

Transcription

1 2015 Atrial Fibrillation Therapy Meds, Shock, or Ablate? D. Scott Kirby MD, FACC Cardiac Electrophysiologist

2 Todays Objectives Atrial Fibrillation evaluation and treatment from an EP perspective Multimodal Therapy of Atrial Fibrillation 52yo M with paroxysmal AF and no previous cardiac history 74yo F with chronic AF and h/o CABG/EF26%/CHF

3 What is Atrial Fibrillation? General Nonlinear electrical conduction in the atrium Multiple organized or disorganized reentrant wavelets in atrium impulses per minute reach the AVN Dormant spontaneous sites become activated and induce fibrillation single or multiple focus firing rapidly initiating and possibly maintaining the fibrillation, resulting from intermittent conduction of impulses to the atria Often originates from site within the pulmonary veins, ( may be more than one focus in more than one vein) or less commonly the LA body, or the right atrium

4 Prevalence and Incidence of AF (US) Adult population in general 0.3% - 0.4% Over 60 years old 2% to 4% Over 75 years old 8% Over 80 years old >10% Total U.S. prevalence 2 million U. S. incidence total 160,000/yr

5 Who has Atrial Fibrillation? Lone atrial fibrillation (absence of identifiable cause) responsible for up to 30% of AF pts. Prevalence in men is twice that of women, but due to longevity, women account for a majority of elderly AF pts

6 Classification of AF First detected Paroxysmal (self-terminating) Episodes that generally last less than or equal to 7 days May be recurrent. Persistent ( not self-terminating) Usually more than 7 days may be recurrent. Permanent (cardioversion failed or not attempted) Fuster V, et al., Circ., 104, 2001, pp

7 Risk Factors for Atrial Fibrillation Age >60yo DM HTN CAD CHF Structural Ht Disease Prior open cardiac surgery Thyroid disease Chronic lung disease OSA Etoh overuse Adrenergic stress serious illness or infection

8 Goals of AF Management AF management Prevention of thromboembolism/ CVA Rate control to minimize symptoms Reduction of AF burden

9 Initial AF Treatment Choose Anticoagulation agent Lovenox/ Coumadin Xarelto/ Eliquis Use CHADS2 or CHA2DS2-VASc scoring to determine TE risk and need for long-term anticoagulation If the AF is persistent and plans are to restore SR, use anticoagulation in everyone. Decide later if to continue. Rate-lowering agents Diltiazem BB Digoxin Amiodarone

10 Initial Diagnostic Evaluation Considerations Underlying metabolic mechanism Structural heart abnormality Valvular - MR Cardiomyopathy Pulmonary venous anomaly ASD Arrhythmic Trigger

11 Initial Studies CBC TSH Echo Holter Stress Test Sleep Study

12 AF Treatment Options Rate control - chemical vs. mechanical Antiarrhythmic medication Cardioversion - external vs. internal Avoid multiple depolarizing fronts by pacing Implantable Atrial defibrillator Compartmentalization Maze Procedure (surgical or catheter based) Ablate individual initiating foci Multimodal Therapy

13 Considerations when Treating Atrial Fibrillation 30% of all AF patients are left undiagnosed 70% of AF patients are suitable for treatment of which: 50% drug treatment is effective 50% do not respond to drugs and are suitable for RF Ablation, surgical Maze procedure, or other treatments Those who respond to drugs initially may develop resistance.

14 Chemically Restoring Sinus Rhythm Considerations May require hospital stay when first started to monitor heart rhythm Medications are effective 30-60% of the time May lose effectiveness over time Many have potentially serious side effects Everyone reacts to the medications differently. May require trialing of several medications to optimize treatment Antiarrhythmic Drugs Class II Metoprolol po or IV Class IC AA Tambocor Rythmol/ Propafenone Class III AA Betapace/ Sotalol) Tikosyn/ Dofetilide Amiodarone

15 Antiarrhythmic Drugs Class IC Rythmol/ Propafenone, Flecainide/Tambocor Excluded if IVS>1.4cm or CAD Class III Betapace, Amiodarone, Tikosyn Check renal function

16 Convert AF to Aflutter Class IC and Amiodarone will organize AF to Aflutter Success rates of ablating typical RA isthmus-dependent Aflutter are 98% and then use AA to control AF Aflutter is still a thromboembolic risk

17 INTERNAL CARDIOVERSION

18 Pulmonary Venous Structure

19 Decussation of LA Muscle Bundles Nathan H, and Eliakim M., Circulation, 1966;34:

20 Maze Ablation Maze (name is based on the concept of a puzzle, the creation of blind alleys and barriers) Catheter Surgical (Cox Maze) Strategic placement of incisions or burns (scars) in both atria to stop the formation and conduction of unorganized impulses and channel a linear electrical impulse in one direction from the top to the bottom of the atria. Designed to be a curative procedure

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22 What Initiates AF?

23 Adenosine for LA Angio 18mg Adenosine, Contract at 35mls,10mls/s and1 sec rise time

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27 Pulmonary Vein Ablation LA ablation strategy Natale, et al; CCF; Cleveland, Ohio; USA

28 Pulmonary Vein Isolation

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34 Conclusions Use the 3 P s +/- recurrent to describe AF Treat AF with 3 goals Anticoagulation/ TE prevention Rate Control Restore SR Control RF s BP, Etoh, and OSA Under 75yo if AF reoccurs on AA meds or AA intolerant, strongly consider PVI Ablation.

35 53yo M 6 220lbs. - HR63bpm - BP 148/92 CBC, CMP, TSH WNL ECHO: EF 60%, mild MR/TR, mild PHTN, LAE 4.6cm, IVS 12mm Holter: no excessive nocturnal bradycardia, no significant pauses, multiple bursts of PAT/PAF seen.

36 Initial Studies Echo: EF 25-35%, mod MR, mod PHTN, LAE 5.8cm, no LV thrombus Holter: dominant rhythm AF, nocturnal bradycardia in AF, symptomatic AF and tachycardia with activity, two brief spontaneous conversions to marked sinus brady. Stress: done ten months prior showed infarction but no ischemia.

37 74yo F - Medical: HTN, NIDDM, dyslipidemia - Surgical: CABG x 4V No sensation of the AF - Describes progressive SOB and decreased exercise tolerance. Denies CP. - Last visit was over six months ago and no EKG done at that time.

38 Treatment Anticoagulation Rate control with Coreg BiV pacing with AF suppression options. Load with Class III AA and plan for cardioversion. ICD protection