Pacemakers. Cardiac resynchronization therapy. Implantable cardioverter defibrillators. Indications, complications, explanation.

1. Pacemakers and ICDs
An Overview
Samir Morcos Rafla, FACC, FESC, FHRS
Emeritus professor of cardiology
Alexandria University
Dr. Samir Rafla Lectures

2. 2
Nomenclature for pacemakers
Letter 1 Letter 2 Letter 3 Letter 4 Letter 5
Chamber
Paced
Chamber
Sensed
Sensing
Response
Programmabilit
y
Antitachycar
dia
Functions
A = atrium A = atrium T=triggered P = simple P = pacing
V=ventricle V=ventricle I = inhibited M=multiprogra
mmable
S = shock
D = dual D = dual D = dual (A
and V
inhibited)
R=rate adaptive D = dual
(shock +
pace)
O = none O = none O = none C=communicati
ng O = none

3. Code Indication Advantages Disadvantages
VVI Intermittent backup
pacing; inactive patient
Simplicity; low cost
Fixed rate;
risk of pacemaker
syndrome
VVIR Atrial fibrillation Rate responsive Requires
advanced
programming
DDD Complete heart block Atrial tracking
restores normal
physiology
No rate
responsiveness;
requires two leads
and advanced
programming
DDDR Sinus node dysfunction;
atrioventricular block and
need for rate
responsiveness
Universal pacer; all
options available by
programming
Complexity, cost,
programming, and
follow-up
evaluation
Common Permanent Pacemakers

4. 48-Apr-18

5. Pacemaker Configurations
VVI
Indications
The combination of AV block and chronic atrial arrhythmias
(particularly atrial fibrillation).

6. Pacemaker Configurations
VDD
Indications
AV block with intact sinus node function (particularly
useful in congenital AV block).

7. Pacemaker Configurations
DDD
Indications
1. The combination of AV block and SSS.
2. Patients with LV dysfunction and LV hypertrophy who need
coordination of atrial and ventricular contractions to maintain
adequate CO.

8. 8

9. Normal VVI pacemaker (rhythm strip).
a patient with a VVI pacemaker implanted for the treatment of
symptomatic complete heart block.
The pacing rate is approximately 75 beats/min (determined by
measuring the time between consecutive pacemaker spikes).
Each pacemaker spike is followed by a paced QRS complex.

10. 10

11. 11

12. 12
Class
I1. Chronic symptomatic third- or second-
degree (Mobitz I or II) atrioventricular block
I2. Neuromuscular diseases (e.g. myotonic
muscular dystrophy, Kearns–Sayre
syndrome, etc.) with third- or second-degree
atrioventricular block
I3.Third- or second-degree (Mobitz I or II)
atrioventricular block: (i) after catheter
ablation of the atrioventricular junction (ii)
after valve surgery when the block is not
expected to resolve
IIa1. Asymptomatic third- or second-degree
(Mobitz I or II) atrioventricular block

13. 13
I1. Intermittent third-degree
atrioventricular block
2. Second-degree Mobitz II
atrioventricular block
3. Alternating bundle branch block
Recommendations for cardiac pacing in
chronic bifascicular and trifascicular block

14. 14
Recommendations for permanent cardiac pacing in
conduction disturbances related to acute
myocardial infarction
I B1. Persistent third-degree heart block
preceded or not by intraventricular
conduction disturbances
2. Persistent Mobitz type II second-
degree heart block associated with
bundle branch block, with or without PR
prolongation
3. Transient Mobitz type II second- or
third-degree heart block associated
with new onset bundle branch block

18. 18

19. 19

20. Table- Indications for lead extraction.
Class I (conditions for which there is general
agreement that leads should be removed). When a
lead or lead fragment causes:
Sepsis (including endocarditis).
Life-threatening arrhythmias.
An immediate or imminent physical threat to the
patient (including retained extraction hardware).
Clinically significant thromboembolic events.
Obliteration or occlusion of all useable veins, with
the need to implant a new transvenous pacing
system.
Interference with the operation of another implanted
device. 20

21. Major complications of lead extraction
Death
Cardiac avulsion or tear requiring intervention
Vascular avulsion or tear requiring intervention
Hemothorax or severe bleeding from any source
requiring transfusion
Pneumothorax requiring chest tube drainage
Pulmonary embolism requiring surgical intervention
Respiratory arrest
Septic shock
Stroke
21

22. Perioperative management with use of electrocautery in patients who
have implanted cardiac devices.
Preoperatively
Identify pacemaker and determine 'reset' mode
Check pacemaker program, telemetry, thresholds, battery status
Deactivate rate response and, if applicable, Vario function
Record pacemaker information
Intraoperatively
Position the indifferent plate for electrocautery away from pacemaker so that
pacemaker is not between electrocautery electrodes
Monitor pulse or oximeter (electrocardiogram is obscured by artifacts)
Have programmer readily available
Use bipolar cautery when possible
Do not use cautery near pacemaker
Use cautery in short bursts
Reprogram, if necessary, if reset mode is hemodynamically unstable
Postopemtively
Check pacemaker program, telemetry, thresholds. Reprogram if necessary
22

23. 23

24. Complications of Implantation
Infection.
Thrombophlebitis .
The “Pacemaker Syndrome” .
Pacemaker Malfunction.

25. Complications of pacing and CRT
implantation
- Lead complications are the main reason for re-
operation after implantation of PM or CRT devices; lead
complications occurred in 3.6% of patients.
- Complication rates were reported in 15.6, 18.3 and
19.7% of the patients at 1, 3 and 5 years,
respectively.
- Major complications were higher with CRT-D,
compared with PM replacements.
- Infection is one of the most worrying post-operative
complications; the incidence was 4.8 per 1000 PM-
years during the first year.
25

26. Complications of Implantation
The “Pacemaker Syndrome”:
* After implantation, in 20%.
* A pt. may present with new complaints or a
worsening of the symptoms that prompted
evaluation & eventual pacemaker therapy.
* These include syncope or near-syncope,
orthostatic dizziness, fatigue, exercise intolerance,
weakness, lethargy, chest fullness or pain, cough,
uncomfortable pulsations in the neck or abdomen,
right upper quadrant pain, and other nonspecific
symptoms.

27. Complications of Implantation
The “Pacemaker Syndrome”:
* The aetiology :is the loss of AV synchrony &
* Is most common with VVI pacing
* Elevated (BNP) & diuresis .
* DDI pacing in a pt. with AV block may result in this syndrome
if the sinus node discharge rate exceeds the programmed rate
of the pacemaker.
* Rx: replacing a VVI pacemaker with a dual-chamber
pacemaker or lowering the pacing rate of the VVI unit.
* Consultation with a cardiologist is recommended .

28. Complications of Implantation
Pacemaker Malfunction :
Failure to capture
* Lead disconnection, break, or displacement
* Exit block
* Battery depletion
Undersensing
* Lead displacement
* Inadequate endocardial lead contact
* Low-voltage intracardiac p waves and QRS complexes
* Lead fracture
Oversensing
* Sensing extracardiac signals: myopotentials
* T wave sensing
Inappropriate rate
* Battery depletion
* Ventriculoatrial conduction with pacemaker-mediated
tachycardia
* 1:1 response to atrial dysrhythmias

29. Pacemaker Malfunction.
Failure to Capture:
* Electrical stimuli delivered by the pacemaker
does not initiate depolarization of the atria or
ventricle

30. Failure to Capture
Possible Causes Corrective Measures
•Threshold rise • Increase output (mA)/check thresholds
•Fractured/dislodged lead • Replace/reposition lead
•Battery depletion • Replace battery
•QRS not visible • Adjust ECG
•Tissue is refractory • Assess mode selection
•Faulty cable connections • Check connections
• Switch polarity (epicardial system

31. 31
Pacing in acute myocardial infarction
Indications for permanent pacing
ClassRecommendations
I1) In the rare cases in which AV block
becomes permanent (after 14 days of
temporary pacing), permanent cardiac
pacing is indicated.

32. 32

33. 33
GUIDELINES OF CRT Indications
Class I
CRT is indicated for patients who have
LVEF <35%, sinus rhythm, left bundle
branch block (LBBB) with a QRS duration >
150 ms, and NYHA Fc II, III, or ambulatory
Fc IV symptoms on guideline-directed
medical therapy (GDMT). (Level of
Evidence: A for NYHA Fc III-IV; Level of
Evidence: B for NYHA Fc II)

34. 34
Class IIa
1. CRT can be useful for patients who have LVEF <
35%, sinus rhythm, LBBB with a QRS duration 120
to 149 ms, and NYHA Fc II, III, or ambulatory Fc IV
symptoms on GDMT. (Level of Evidence: B)
2. CRT can be useful for patients who have LVEF <
35%, sinus rhythm, a non-LBBB pattern with a QRS
duration > 150 ms, and NYHA Fc III/ambulatory Fc IV
symptoms on GDMT. (Level of Evidence: A)
3. CRT can be useful in patients with atrial
fibrillation and LVEF < 35% on GDMT if: (a) The
patient requires ventricular pacing or otherwise
meets CRT criteria and (b) AV nodal ablation or
pharmacologic rate control will allow near 100%
ventricular pacing with CRT. (Level of Evidence: B)

35. 35

36. 36

37. 37
CRT- Isolated loss of LV pacing

40. IMPLANTABLE CARDIOVERTER-
DEFIBRILLATORS ICD
Class I Indications:
1. Cardiac arrest resulting from VF or VT not caused
by a transient or reversible event.
2. Spontaneous sustained VT.
3. Syncope of undetermined origin with clinically
relevant, hemodynamically significant sustained VT or
VF induced at electrophysiologic study when drug
therapy is ineffective, not tolerated, or not preferred.
4. Nonsustained VT with coronary artery disease, prior
myocardial infarction, left ventricular dysfunction, and
inducible VF or sustained VT at electrophysiologic
study that is not suppressible by a class I
antiarrhythmic drug.

41. Recommendations on Implantation of ICDs without
Cardiac Resynchronization Capabilities
Primary Prevention
ICD therapy is recommended for primary
prevention to reduce total mortality by a
reduction in SCD in patients with LV dysfunction
due to prior MI who are at least 40 days post-MI,
have an LVEF ≤30%–40%, are NYHA Class II or
III receiving chronic optimal medical therapy, and
have a reasonable expectation of survival with a
good functional status for more than 1 year.
41

42. Secondary Prevention
- ICD therapy is recommended for secondary
prevention of SCD in patients who survived VF or
hemodynamically unstable VT, or VT with syncope and
who have an LVEF ≤40%, who are receiving chronic
optimal medical therapy, and who have a reasonable
expectation of survival with good functional status for
more than 1 year.
- An ICD should be implanted in patients with
nonischemic DCM and significant LV dysfunction who
have sustained VT or VF, are receiving chronic optimal
medical therapy, and who have reasonable expectation
of survival with good functional status for more than 1
year.
42

43. 43
ICD Implantation Within 40 Days of a
Myocardial Infarction
In the great majority of situations, ICD
implantation should be performed at least 40
days after an MI. During the acute phase
of MI, it is often unclear how much recovery of
cardiac function will occur following hospital
discharge, and in some cases, the clinical
condition is so severe that ICD implantation
would be of little value.

44. 44
Leadless Pacemaker

46. References
2013 ESC Guidelines on cardiac pacing and cardiac
resynchronization therapy. European Heart Journal
(2013) 34, 2281–2329.
HRS/ACC/AHA Expert Consensus Statement on the
Use of Implantable Cardioverter-Defibrillator Therapy
in Patients Who Are Not Included or Not Well
Represented in Clinical Trials. Circulation.
2014;130:94-125
An Overview of Current Cardiac Resynchronization
Therapy. Acta Cardiol Sin 2013;29:496504
46