1. Bradyarrhythmia’s, Pacemaker’s & Complex Devices
Dr Chris McAloon
Medical Student Teaching

2. Overview Interpreting Bradyarrhythmia’s
Different types of Bradyarrhythmia’s
Pacemakers
Complex Devices

3. “ Always look at the patient”
First Rule
“ Always look at the patient”

4. Conducting system

5. Need diagram here

7. Heart Blocks
NSR
Sinus brady
SSS
Sinoatrial block
Sinus arrest

8. Heart Blocks 1st degree 2nd degree Mobitz Type 1 Mobitz Type 2
2:1, 3:1 AVB
3rd degree
Fascicular block - LAD, RAD, TFB
LBBB, RBBB
AF, Flutter

9. Reversible Causes of Slow Heart Rate
Drug therapy
Acute Myocardial Infarction
Hypothermia
Hypothyroidism
Athletic Heart
Vaso-vagal mechanisms

10. Complete AV Block
All patients with persistent or intermittent complete AV block should be paced unless there is a reversible cause Irrespective of symptoms
Reversible causes include recent inferior MI,
hypothyroidism and drugs
This includes patients with congenital CHB
If you are not going to pace, you really need to be able to justify that decision

11. Sinus Node Dysfunction
Inappropriate bradycardia Intermittent – faintness / syncope Persistent – SOB / muscle fatigue / exhaustion
Associated atrial tachyarrhythmias / AV Block Intermittent – palpitations / faintness / syncope Persistent – SOB / muscle fatigue / exhaustion
Associated clinical syndromes Embolic Heart Failure

12. The ‘ALS’ Approach Is there electrical activity?
What is the ventricular (QRS) rate?
Is the QRS rhythm regular or irregular?
Is the QRS complex width normal or prolonged?
Is there atrial activity present?
Is the atrial activity related to ventricular activity, if so how?

13. The Heart Block System
Are the P waves associated with the QRS complex at all?
No = This is 3rd Degree Heart Block
Yes= Move to Question 2

14. Third Degree/ Complete Heart Block
Measure P waves out – will be regular completely dissociated to QRS
Broader QRS lower the ventricular escape

15. The Heart Block System
Is there one P wave to one QRS, with a prolonged PR interval that is not progressing (in length)?
Yes= This is 1st Degree Heart block
No = Go to question 3

16. First Degree Heart Block
PR interval prolonged, 1:1

17. The Heart Block System
3. Is there progression in PR interval duration until there is a non-conducted P wave?
Yes= This is Wenckebach
No = Go to question 4

18. Mobitz Type 1/ Wenckebach
PR interval prolonged, 1:1

19. The Heart Block System Therefore it must be Mobitz type 2
Mobitz type 2 difficult to explain
P waves conducted normal PR interval
There are P waves that are not conducted
Not always a specific block
2:1
3:1
4:3

20. Mobitz Type 2
PR interval prolonged, 1:1

21. Mobitz 2 – 3:1 Block
PR interval prolonged, 1:1

22. SA Slow Sinus Rate
AV Block
Atrial
Tachy-arrhythmias

23. DVLA Disorder Group 1 Entitlement - ODL
Group 2 Entitlement – VOC - LGV / PCV
Comments
Simple Faint
Yes
No notification
TLOC/ Awareness
Low recurrence risk
4 weeks
3 months
High recurrence risk
4 weeks if cause identified & treated
6 months if no cause identified
3 months if cause identified & treated
1 year if no cause identified
High risk ...
SHD, abnormal ECG, previous TLOC
Cough syncope
Until coughing controlled
Until coughing controlled and free of TLOC for 5 years
If cough induced asystole treated by pacemaker may regain license
ARRHYTHMIA
SA disease, significant A-V conduction defect ,atrial flutter/fibrillation or narrow or broad complex tachycardia
4 weeks if cause identified & controlled
If arrhythmia controlled for ≥ 3/12 and LV EF ≥ 0.4
Transient arrhythmias during ACS do not require assessment under this section
PACEMAKER IMPLANT
Includes box change
1 week
6 weeks
LVEF < 0.4 (or ? >0.35) is a bar to Group 2 Entitlement for ALL cardiac conditions

24. Pacemaker’s

25. History of Firsts in Pacing
1957 Transistorized, battery powered wearable pacemaker
Totally implanted pacemaker (epicardial)
1959 Endocardial lead
1969 “Demand” pacemaker
1975 Lithium Iodide battery
1980 Rate responsive pacemaker
1994 Potential advantages of multi-site pacing
1995 Pre-pectoral ICD
2001 Combined CRT and ICD device (CRT-D)

26. Pacing Indications

27. Paced Patients: Predominant ECG Indication
The grey zone
In younger < than CHB
In older CSM + ve
BPEG / HRUK National Database
Heart Rhythm 2007;4: Supplement 5, AB 16-6

28. Paced Patients: Predominant Presenting Symptom
BPEG / HRUK National Database
Heart Rhythm 2007;4: Supplement 5, AB 16-6

29. Pacing Indications AV Block Complete Heart Block
Second degree AV block (High block or symptoms)
Reversible: Inferior MI, Hypothyroidism
Sinus Node Disease
Chronotropic Incompetence
If resting HR in day time <30
Atrial Fibrillation
Bradycardia
Bradycardia in presence drugs for uncontrolled Tachycardia

32. International Codes Pacemaker
First Letter = Chamber(s) being PACED (A,V,D) Second Letter = Chamber(s) being SENSED Third Letter= How the device RESPONDS to SENSED Event (Inhibits, Triggers, Dual (I+T)) Fourth Letter = Added feature e.g R = Rate Response

33. Pacemaker Basic’s

34. A Unipolar System

35. A Bipolar System

36. What is the PPM?
VVI

37. What is the PPM?
AAI

38. What is the PPM?
DDD

39. What is the PPM?
DDD

40. Electrodes -- Fixation Mechanism
Passive Fixation Mechanism – Endocardial
Tined
Finned
Canted/curved
Passive fixation in relation to endocardial leads means that no part of the lead itself is actually embedded in the endocardium. Rather, the lead tip is trapped within the trabeculae and/or is held in position by its pre-formed shape (e.g., J-lead in atrium).
Passive fixation leads commonly use tines or fins to "catch" trabeculi in the heart, or the lead is canted or curved to help place and hold the lead tip in a certain position.
Passive anchoring devices, such as flanges or wedge tips, cages and balloons were early attempts to solve the dislodgment problems of early pacing leads. However, only after tined leads were introduced by Medtronic in 1976 did a true solution to dislodgment emerge with regard to passive fixation.
Today, there is approximately a 1-2% dislodgment rate 1, 2, 3, 4, 5, 6 with passive fixation leads:
1 - 2% in the atria,1, 2, 6
1 - 2% in the ventricle.1, 3, 4, 5
References:
1 Gammage MD, Marshall HJ, Harris JI. Five-year experience with polyurethane, passive fixation, steroid-eluting leads. PACE ;(Pt II):842. Abstract.
2 Hua W, Mond HG, Strathmore N. Chronic steroid-eluting lead performance: a comparison of atrial and ventricular pacing. Pacing Clinical Electrophysiology. 1995;20(1 Pt 1):17-24.
3 Kazama S, Nishiyama K, Machii M, Tanaka K, Amano T, Nomura T, Ohuchi M, Kasahara S, Nie M, Ishihara A. Long-term follow-up of ventricular endocardial pacing leads. Jpn Heart J. 1993;34(2):
4 Mayer DA, Tsapogas MJ. Pacemakers: dual or single chamber implantation. Vasc Surg. 1992;26(5):400-7.
5 Miller GB, Leman RB, Kratz JM, Gillette PC. Comparison of lead dislodgment and pocket infection rates after pacemaker implantation in the operating room versus the catheterization laboratory. Am Heart J. 1998;115(5):
6 Mond HG, Hua W, Wang CC. Atrial pacing leads: the clinical contribution of steroid elution. Pacing Clinical Electrophysiology. 1995;18(9 Pt 1):
7 Glikson M, von Feldt LK, Suman VJ, Hayes DL. Short- and long-term results with an active fixation, bipolar, polyurethane-insulated atrial pacing lead. Pacing Clinical Electrophysiology ;19(10):
8 Stirbys P. Implantation of double screw-in leads. Pacing Clinical Electrophysiology. 1988;11(10):

41. Electrodes – Fixation Mechanism
Active Fixation Mechanism – Endocardial
Fixed screw
Extendible/retractable
Active fixation means that part of the lead actually embeds in the heart tissue for fixation via a screw-in helix electrode. Extendible/retractable and fixed screw mechanisms are the most common active fixation methods.
Fixed Screw leads provide excellent stability. The lead body must be turned in a counter-clockwise rotation during insertion of the lead. Sense mapping can be done prior to fixing the screw to the myocardium. The lead body is then turned in a clockwise rotation to fix the screw to the myocardium.
Extendible/Retractable screw-in leads provide excellent stability. The screw is retracted to prevent damage to the veins and cardiac structures during lead advancement. The ability to retract the screw makes entanglement in cardiac structures less likely. The screw is retracted during transvenous introduction and during sense mapping and extended for lead fixation. Care must be taken not to over-extend or over-retract the screw with this type of screw mechanism.
Today, there is approximately a 1 - 4% dislodgment rate 6, 7, 8 with active fixation leads:
1 - 4% in the atria 6, 7, 8
<1% in the ventricle.8
References:
6 Mond HG, Hua W, Wang CC. Atrial pacing leads: the clinical contribution of steroid elution. Pacing Clinical Electrophysiology. 1995;18(9 Pt 1):
7 Glikson M, von Feldt LK, Suman VJ, Hayes DL. Short- and long-term results with an active fixation, bipolar, polyurethane-insulated atrial pacing lead. Pacing Clinical Electrophysiology ;19(10):
8 Stirbys P. Implantation of double screw-in leads. Pacing Clinical Electrophysiology. 1988;11(10):

42. Pacemaker Prescription
Re-establish stable heart rate
Restore AV synchrony
Achieve chronotropic competence
Achieve normal physiological activation and timing
A lead if normal A function
V lead if actual / threatened AV HB
Rate modulation if slow
Avoid VV dysnchrony
HB > SA (sinus) > AF

43. 55% A + V Leads (Dual Chamber) 44% V Lead only (mostly in AF)
1% A Lead only
55% A + V Leads (Dual Chamber)
44% V Lead only (mostly in AF)
V lead RV apex
AN AUDIT OF PACING PRACTICE IN THE 33 CARDIAC NETWORKS SERVING ENGLAND AND WALES C. Plummer1, A. Cunningham2, M. Cunningham2, R. Charles2, J. McComb1. 1Freeman Hospital, Newcastle upon Tyne, UK 2National Pacemaker and ICD Database, Central Cardiac Audit Database, London, UK
Introduction: Pacemaker implantation rates and pacing mode selection are known to vary widely between Western countries despite similar guidelines on the indications for implantation. The National Institute for Health and Clinical Excellence (NICE) published guidance on pacing mode for symptomatic bradycardia due to sick sinus syndrome (SSS) and/or atrioventricular block (AVB) in February This recommends dual chamber (DDD±R) pacing unless patients are in continuous atrial fibrillation (AF), when a ventricular (VVI±R) system is indicated, or have SSS without AVB when an atrial (AAI±R) system may be appropriate. The guidance recognises patient-specific factors which may favour VVI±R. We have audited UK pacing practice against these standards at the level of cardiac networks.
Methods: The National Pacemaker Database is part of the Central Cardiac Audit Database in the NHS Information Centre in London. It registers all pacemakers and implantable cardioverter defibrillators implanted in the UK. Data for 2003 and 2004 were cross-checked with individual pacing centres and are 98% complete. The data were then analysed by individual pacing centre and the cardiac networks they serve to produce a database including all 33 networks covering all 52.9 million people in England and Wales.
Results: Age and sex corrected annual pacing rates varied between networks from to 513.1/million and pacing for complete heart block (CHB), from 68.4 to 126.5/million. The proportion of devices implanted for CHB was negatively correlated with total pacing rate (r2 = 0.284). The mean proportion of patients receiving AAI±R devices was 1.1%, far below the proportion paced for SSS of 26.9%. A mean of 42.2% of patients received VVI±R devices while only 23.8% were in AF. A local audit demonstrated that all 35 patients in sinus rhythm (SR) receiving a VVI±R device out of a total of 134 VVI±R (26.1%) devices implanted in the year, had documented comorbidity favouring single chamber pacing. The number receiving VVI±R devices in SR in excess of this varied between 18 to 136 devices/million/year, 4.7 to 35.7% of all devices implanted in a network.
Conclusions: There are large variations in pacing practice in England and Wales which cannot be explained on clinical criteria. Some pacing centres in the UK will need to change practice significantly if they are to follow National guidance on pacing mode: A large number of patients with SSS are receiving DDD±R pacing systems when AAI±R is recommended. An even larger number in SR appear to be receiving VVI±R devices when DDD±R is recommended. This database provides a powerful audit tool to address these inconsistencies in practice.
NICE – recommends A lead if not in continuous AF
UK 2006 : 46% AVB (not in AF), 24% AF + AVB and 30% SA Disease
AAI(R) pacing for SA disease is very low a) because of small but definite risk of AV block and when it occurs for approx 50% the first manifestation is syncope … b) legal issues (US) V

44. Complex Devices
RBBB

45. Complex Devices

46. What can be done?

47. What can be done?

48. Technology

51. Heart Failure and CRT Cardiac resynchronization therapy (CRT)
Heart failure common and disabling condition
Cardiac resynchronization therapy (CRT)
Applicable to ~1/3 of all symptomatic HF patients
Improvement in long term survival
NICE indications
NYHA III/IV, Optimal medical therapy
LVEF <35%
QRS > 120ms
However, 20-30% non responders to CRT

54. CARE-HF: CRT vs Medical Therapy - Primary End Point
Cleland, J. et al. N Engl J Med 2005;352:

56. NICE Guidance 95 & 120

60. Global Heroes 2012: 10 mile run
Susan Filler was an avid runner
2007 survived Cardiac Arrest
ARVD diagnosed & ICD implanted
Completed Boise & Canada Ironman
Patrick Grayson 21
Long QT diagnosed at 11
At 12 Cardiac Arrest & ICD implanted
Protection of ICD gave confidence to run
February 2012 ran 1st marathon
Erin Clark
20 years ago SCA, diagnosed Long QT
BB 1st, then implanted ICD.
ICD gave confidence to be active as protection
1 year ago started running

61. What patients say about ICD
When I die will this keep shocking me? In my coffin?
One day I want to join my wife – how can I do that with an ICD?
Can I be comfortable at the end of my life?
Will Deactivation hurt? Do I need surgery?
Will I die immediately after the ICD is deactivated?
I feel like the bionic man – can I die with this?

62. ESC GUIDANCE 2010
‘It seems clear at this point that this device is in your best interest, but you should know at some point if you become very ill from your heart disease or another process you developing the future, the burden of this device may outweigh its benefit. While that point is hopefully a long way off, you should know that turning off your defibrillator is an option.’
‘Now that we’ve established that you would not want resuscitation in the event your heart was to go into an abnormal pattern of beating, we should reconsider the role of yourdevice. In many ways it is also a form of resuscitation. Tell me your understanding of the device and let’s talk about how it fits into the larger goals for your medical care at this point.’
‘Clinicians may be concerned that withdrawing life-sustaining treatments such as CIED (ICD) therapies amounts to assisted suicide or euthanasia. However, two factors differentiate withdrawal of an unwanted therapy from assisted suicide and euthanasia: the intent of the clinician, and the cause of death. First, in withdrawing an unwanted therapy, the clinician’s intent is not to hasten the patient’s death, but rather, to remove a treatment that is perceived by the patient as a burden.’