Pacing in Bardyarrhythmia

Main Reference◦ ACC/AHA/HRS 2008 Guidelines for Device-Based

Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation. 2008 May 27;117(21):e350-408.

Indications for Pacing

Complete (3rd degree AV block)◦ Complete A V dissociation, regular R waves,

Atrium>Ventricle Second degree AV block

◦ Mobitz I (Wenckebach) Progressive increase in PR interval before block Shortening of RR intervals P-P equal (*ventricular phasic

dysrhythmia)◦ Mobitz II

Fixed PR interval before and after block, can be high grade (≥2 non-conducted P waves) or 2:1.

First degree AV block◦ PR interval >200ms

Indications for Permanent pacing in Aquired Atrioventricular Block

Third degree or second degree block:◦ Class 1 indication for pacing if:

Bradycardia associated with symptoms Need for drug therapy resulting in

symptomatic bradycardia Asymptomatic with pause >3.0s or escape

<40bpm or broad complex escape (below level of AV node)

Asymptomatic with AF and pause >5.0secs Asymptomatic but associated neuromuscular

disease Block occurring during exercise regardless of

presence of ischaemia.

Permanent pacing is Indicated in Aquired Atrioventricular Block

Class IIa recommendations◦ Asymptomatic adults, resting rate >40bpm and

without structural heart disease.◦ Asymptomatic adults with level of block

discovered below the AV node at electrophysiological study

◦ Symptoms of pacemaker syndrome◦ Asymptomatic type II AV block with narrow QRS

(note wide QRS makes this class I indication)

Permanent pacing is Reasonable in Aquired Atrioventricular Block

Pacing is not indicated or is harmful for the following:◦ Asymptomatic 1st degree heart block◦ Asymptomatic Mobitz type 1 Wenckebach◦ Transient or unlikely to recur, during episodes of

hypoxia in the sleep apnoea syndromes.

Permanent pacing is Not Indicated in Aquired Atrioventricular Block

Why do we need pacing in AV block?

Unpaced group followed between 1960-1965 before pacing was introducedi.e. Self selected ‘survivors’

From H Sniddon “ Death in Long-term paced patients” Br Heart Journal 1974; 36:1201-1209

Copyright ©2008 American College of Cardiology Foundation. Restrictions may apply.

Epstein, A. E. et al. J Am Coll Cardiol 2008;51:e1-e62

Selection of Pacemaker Systems for Patients With Atrioventricular Block

Class I (indicated for:)◦ Documented symptomatic bradycardia including

frequent sinus pauses◦ Chronotropic incompetence◦ Essential concomitant use of rate slowing drugs

Class IIa (Reasonable in:)◦ Symptoms not documented but resting

HR<40bpm◦ Unexplained syncope and abnormal EP study

Class IIb (“may be considered in”:)◦ Asymptomatic and resting HR ≤ 40bpm

Indications for Permanent pacing in Sick Sinus Syndrome

Copyright ©2008 American College of Cardiology Foundation. Restrictions may apply.

Epstein, A. E. et al. J Am Coll Cardiol 2008;51:e1-e62

Selection of Pacemaker Systems for Patients With Sinus Node Dysfunction

Pacing in SSS (VVI vs AAI)

HR Anderson et al. Lancet. 1997; 9086: 1210-1216

Overall Survival

Survival CVS death

Freedom from AF

Freedom from Chronic AF

Pacing in SSS (VVI vs. AAI)

Rosenqvist et al. Am Heart J; 1988;116: 16-22

•Retrospective study

of 168 patients

•AF significantly

greater in VVI group

c.f. AAI group

47% vs 6.7%

•Mortality

• VVI=23%

• AAI=8%

(p=0.045)

Pacing in SSS (DDD vs. VVI)

Lamas et al. NEJM 2002; 346: 1854

RCT of 2010 pts with SSS1014 DDD996 VVI

AF developed in:VVI 27.1%DDD 21.4% (p=0.004)

Note still high rate of AF with V pacing in either arm

Pacing in SSS (MVP vs. DDD)

Sweeny et al. NEJM. 2007; 357: 1000-8

Comparison of minimal ventricular pacing (MVP) and conventional DDD.

RCT of 1065 patientsMVP 530DDD 535

Primary endpoint time to Afib (trial stopped early as endpoint met)

AFMVP: 7.9%DDD: 12.7% (p=0.004)HR 0.6 (0.41-0.88)

Ventricular pacing in SSS is bad!

◦ Increased risk of death

◦ Increased risk of stroke

◦ Increased risk of AF

DDD pacing is better

◦ No difference in Mortality

◦ Increased risk of AF but better than VVI

Atrial based pacing is best!

Summary of data to date on pacing and SSS

DANPACE * DDD vs AAI

Class I◦ Syncope with clear carotid events and CSM producing

pause >3 secs Class IIa

◦ Syncope with CSM >3secs Class IIb

◦ ‘Significantly’ symptomatic neurocardiogenic syncope associated with documented bradycardia spontaneously or at Tilt table

Class III (Not-indicated)◦ Positive CSM in absence of symptomsSituational vasovagal syncope

Pacing in Hypersentive Carotid Syndrome and Neurocardiogenic Syncope

102 patients followed for 7-30 years Stokes-Adams attacks in 27; fatal in 8

◦ First attack fatal in 6/8◦ 19 survived and paced◦ Long QTc (>0.45s) observed in 7 – all 7 had

subsequent SA attack. All 7 had previously normal QTc. 3 died, 4 paced survived.

Ventricular rate gradually decreased with age Mitral regurgitation developed in 16 (4 died) A PPM reduced the risk of death

Pacing for congenital AV block

Michaelsson et al. Circulation 1995;92:442-9

CLASS I1. Permanent pacemaker implantation is indicated for advancedsecond- or third-degree AV block associated with symptomaticbradycardia, ventricular dysfunction, or low cardiac output.(Level of Evidence: C)2. Permanent pacemaker implantation is indicated for SND withcorrelation of symptoms during age-inappropriate bradycardia.The definition of bradycardia varies with the patient’s age andexpected heart rate. (Level of Evidence: B) (53,86,253,257)3. Permanent pacemaker implantation is indicated for postoperativeadvanced second- or third-degree AV block that is notexpected to resolve or that persists at least 7 days after cardiacsurgery. (Level of Evidence: B) (74,209)4. Permanent pacemaker implantation is indicated for congenitalthird-degree AV block with a wide QRS escape rhythm, complexventricular ectopy, or ventricular dysfunction. (Level of Evidence: B)(271–273)5. Permanent pacemaker implantation is indicated for congenitalthird-degree AV block in the infant with a ventricular rate lessthan 55 bpm or with congenital heart disease and a ventricularrate less than 70 bpm. (Level of Evidence: C) (267,268)

Recommendations for Permanent Pacing in Children,

Adolescents, and Patients With CongenitalHeart Disease

Pacing for Atrioventricular Block AssociatedWith Acute Myocardial Infarction

CLASS I

1. Permanent ventricular pacing is indicated for persistent second degreeAV block in the His-Purkinje system with alternatingbundle-branch block or third-degree AV block within or below theHis-Purkinje system after ST-segment elevation MI. (Level ofEvidence: B) (79,126–129,131)2. Permanent ventricular pacing is indicated for transient advancedsecond- or third-degree infranodal AV block and associatedbundle-branch block. If the site of block is uncertain, an electrophysiologicalstudy may be necessary. (Level of Evidence: B)(126,127)3. Permanent ventricular pacing is indicated for persistent andsymptomatic second- or third-degree AV block. (Level of Evidence:C)

Recommendations for Cardiac ResynchronizationTherapy in Patients With Severe Systolic Heart FailureCLASS I

1. For patients who have LVEF less than or equal to 35%, a QRS duration greater than or equal to 0.12 seconds, and sinusrhythm, CRT with or without an ICD is indicated for the treatment of NYHA functional Class III or ambulatory Class IV heart failure symptoms with optimal recommended medical therapy. (Level ofEvidence: A) (222,224,225,231)

IPG

Basic Biomechanics of Pacing

Right Atrial Lead

Implantable Pulse generator

(CAN)

Right Ventricular Lead

Left Ventricular Lead

Basic Biomechanics of Pacing

UnipolarLarge Spike on ECG

BipolarSmall Spike on ECG

Circuit between Lead tip and IPG

Circuit between two poles at the end of the lead

IPG

RV Lead Placement

Septal and Apical Apical

RV Lead Placement

RV Outflow Septum Apical

72 year old female attends ER with episode of syncope. No prodrome.

Telemetry recording as below What does the Trace show? What is the optimum treatment

Case 1

65 male admitted with seizures.

Case 2

Case 2

Asymptomatic 54 year old male

Case 3

24 post op

Case 4