Cardiac rhythm management

1. CARDIAC
RHYTHM
MANAGEMENT
Shivam Keshari
MRT13UGBBM015
Shobhit University, Meerut

2. CRM
This major service provides diagnosis and
treatment for disorders that affect the heart's
electrical system and cause rhythm problems.
Heart rhythm disorders are managed in a
number of ways, including medications,invasive
electrophysiologic procedures, pacemakers,
implantable defibrillators, and biventricular
pacemakers.

3. Pacemaker Implantation
A pacemaker is an electrical system that reads
and delivers cardiac electrical impulses. By
"reading" these signals, the pacemaker is able
to monitor the heart's activity and respond
appropriately. A pacemaker helps to pace the
heart when the natural rate is too slow
(bradycardia) to pump enough blood to the
body

4. Defibrillator Implantation
• A defibrillator device is implanted to monitor
the regularity of the heartbeat and deliver an
electric shock should the heart begin
fibrillation (fast or slow movement of cardiac
muscle fibers)

5. Biventricular Pacing
This technology is used to treat patients who have
congestive heart failure. In a normal heart, the regions of
the left ventricle pump in sync. The electrical system can be
impaired enough to make the regions of the left ventricle
pump out of sync in a person with congestive heart failure,
so not enough blood gets pumped to the body, which heart
failure symptoms such as shortness of breath and fatigue.
To remedy this, resynchronize the timing of the electrical
impulses in the heart with biventricular pacemakers that
help the regions of the left ventricle pump in time to
increase efficiency of contraction

7. Anatomy & Physiology of Heart

9. Conduction System of Heart

10. SA NODE :
-AT THE UPPER POSTERIOR PART OF THE
ATRIUM
-PRIMARY PACEMAKER
-DISCHARGES ELECTRICAL IMPULSES 60-100 A
MINUTE
AV NODE :
-RECEIVES IMPULSES FROM SA NODE
-SLOW THE CONDUCTION AND DELAYS THE
INPUT IN ORDER ATRIUMS TO VENTRICULS
COMPLETELY
-BLOCK SOME OF THE IMPULSES TO PREVENT
GOING THE HEART TACHY
-SERVES AS A BACK UP PACEMAKER IF SA
NODE
DISCHARGES(ELECTRICAL IMPULSES OF 40-
60 A MINUTE)
PURKINJE FIBERS:
-RECEIVES IMPULSES FROM BUNDLE
BRANCHES
-DISCHARGES ELECTRICAL IMPULSES 20-40
A MINUTE

12. ECG
HEART RATE
-To determine the ventricular rate, count
the QRS complex on a 6 sec paper and
multiply by 10
WAVES
-P wave: atrial depolarization
-QRS complex :ventricular depolarization
-Twave :Ventricular repolarization
INTERVALS
-PR :0.12-0.20 sec
-QRS :under 0.10sec
-QT:under 0.38 sec

13. Major cardiac arrhythmias
SINUS RYTHMS ATRIAL
RYTHMS
VETRICULAR
RHYTHMS
ATRIO-
VENTRICULAR (AV)
RHYTHMS
SINUS BRADY PREMATURE
ATRIAL
CONTRACTION(PA
C)
PREMATURE
VENTRICULAR
CONTRACTION(PV
C)
1ST DEGREE AV
BLOCK
SINUS
TACHICARDIA
ATRIAL FLUTTER VENTRICULAR
TACHICARDIA
2ND DEGREE AV
BLOCK TYPE I
SINUS ARRYTHMIA ATRIAL
FIBRILATION
VENTRICULAR
FIBRILATION
2ND DEGREE AV
BLOCK TYPE II
SINUS ARREST ASYSTOLE 3RD DEGREE AV
BLOCK

14. Sinus rhythms
• CHARACTERISTICS
• - usually 60-100bpm, but can be slower or faster
• -irregular with respiration, HR increases with inspiration and
decreases with expiration
• -PR 0.12-.20
• QRS0.10 or less
• WHAT TO DO?
• NOTHING !!!
• MEDICATION
• If hemodynamic compromise is present ATROPINE
NORMAL SINUS RHYTHM

15. SINUS RHYTMS
CHARACTERISTICS
-less than 60bpm
-regular PP and RR
-PR 0.12-.20
QRS0.10
WHAT TO DO?
-watch the patient for s/s of bradycardia
-If symptomatic; iv access, o2,
transcuteneus pacing
MEDICATION
Atropine 0.5mg ivp
SINUS BRADYCARDIA

16. Sinus rhythms
• CHARACTERISTICS
• - 101-150bpm
• -regular PP and RR
• -PR 0.12-.20
• QRS0.10 or less
• WHAT TO DO?
• -watch the patient for s/s of Tachycardia
• -correct underlying problems/Never shock ST
• MEDICATION
• Atenelol/Meteprolol (Beta blockers)
SINUS TACHYCARDIA

17. Sinus rhythms
• CHARACTERISTICS
• - Rate varies because of the pause
• -irregular rhythm
• -PR 0.12-.20
• QRS0.10 or less
• WHAT TO DO?
• If transient and major s/s of decline monitor the pt
• If more than 3 sec. ATROPINE, Bedside TPI or Possible PPI
insertion
• MEDICATION
• ATROPINE
SINUS ARREST

18. Atrial rhythms
• CHARACTERISTICS
• - Rate; Depends on the underlying rhythm but usually w/i
normal limits
• -Regular rhythm, except the premature beats
• -PR may be normal or prolonged
• QRS0.10 or less but might be wide
• WHAT TO DO?
• NOTHING!!!
• Reducing stress, stimulants(coffee), treating CHF may help
• MEDICATION
• If needed beta blockers, CA blockers or anxiety meds
PREMATURE ATRIAL COMPLEX

19. Atrial rhythms
Atrial Fibrillation
No discernable p-waves preceding the QRS complex
The atria are not depolarizing effectively, but
fibrillating
Rhythm is grossly irregular
If the heart rate is <100 it is considered controlled a-fib,
if >100 it is considered to have a “rapid ventricular
response”
AV node acts as a “filter”, blocking out most of the
impulses sent by the atria in an attempt to control the
heart rate
Atrial Fibrillation

20. Atrial rhythms
Atrial Flutter

21. Ventricular rhytms
PREMATURE VENTRICULAR COMPLEX
 CHARACTERISTICS
 - Rate; Depends on the underlying rhythm
 -Regular rhythm, except the premature beats
 -PR no PR because ectopy comes from ventricles
 QRS more then 0.12, wide and bizarre looking
 WHAT TO DO?
 NOTHING!!!
 Monitor the pt, if frequent check if they have enough
cardiac output

22. Ventricular rhythms
• Ventricular Tachycardia
– No discernable p-waves with QRS
– Rhythm is regular
– Atrial rate cannot be determined, ventricular rate is between 150-250
beats per minute
– Must see 4 beats in a row to classify as v-tach
– THIS IS A DEADLY RHYTHM
-If patient awake and alert, monitor patient and call physician
If patient has no vital signs, call code and start CPR
Defibrillate
VENTRICULAR TACHICARDIA

23. Ventricular rhythms
VENTRICULAR FIBRILATION
Ventricular Fibrillation
No discernable p-waves
No regularity
Unable to determine rate
Multiple irritable foci within the
ventricles all firing simultaneously
May be coarse or fine

24. AtrioVentricular (AV) blocks
First Degree Heart Block
P-wave for every QRS
Rhythm is regular
Rate may vary
Av Node hold each impulse longer than
normal before conducting normally
through the ventricles
Prolonged PR interval
Looks just like normal sinus rhythm
FIRST DEGREE AV BLOCK

25. AtrioVentricular (AV) blocks
• Second Degree Heart Block
• Mobitz Type I (Wenckebach)
– Some p-waves are not followed by QRS complexes
– Rhythm is irregular
• R-R interval is in a pattern of grouped beating
– Rate 60-100 bpm
– Intermittent Block at the AV Node
• Progressively prolonged p-r interval until a QRS is blocked
completely
SECOND DEGREE AV BLOCK
TYPE -I

26. AtrioVentricular (AV) blocks
TYPE -II

27. AtrioVentricular (AV) blocks

28. Implantable pulse
generator (IPG)
Lead wire(s)
Implantable Pacemaker Systems Contain
the Following Components
PACEMAKER BASICS

29. • Pulse generator: power
source or battery
• Leads or wires
• Cathode (negative
electrode)
• Anode (positive
electrode)
• Body tissue
IPG
Lead
Anode
Cathode
Pacemaker Components Combine with
Body Tissue to Form a Complete Circuit

30. • Contains a battery that
provides the energy for
sending electrical
impulses to the heart
• The circuitry that
controls pacemaker
operations
Circuitry
Battery
The Pulse Generator:

31. • Deliver electrical
impulses from the pulse
generator to
the heart
• Sense cardiac
depolarization
Lead
Leads Are Insulated Wires That:

32. • Deliver electrical
impulses from the pulse
generator to
the heart
• Sense cardiac
depolarization
Lead
Leads Are Insulated Wires That:

33. • Stimulate cardiac depolarization
• Sense intrinsic cardiac function
• Respond to increased metabolic demand by providing
rate responsive pacing
• Provide diagnostic information stored by the pacemaker
Most Pacemakers Perform Four Functions:

34. 34
Capture
Depolarization of atria and/or ventricles in response to
a pacing stimulus
Sensing
Ability of device to detect intrinsic cardiac activity
Undersensing: failure to sense
Oversensing: too sensitive to activity

35. Rate Responsive Pacing
• When the need for oxygenated blood
increases, the pacemaker ensures that the
heart rate increases to provide additional
cardiac outputAdjusting Heart Rate to Activity
Normal Heart Rate
Rate Responsive Pacing
Fixed-Rate Pacing
Daily Activities

36. A Variety of Rate Response Sensors Exist
• Those most accepted in the market place
are:
– Activity sensors that detect physical movement
and increase the rate according to the level of
activity
– Minute ventilation sensors that measure the
change in respiration rate and tidal volume via
transthoracic impedance readings

37. 37
Types
1. Asynchronous/Fixed Rate
2. Synchronous/Demand
3. Single Chamber
4. Dual Chamber
5. Multisite Pacing

38. Single-Chamber System
• The pacing lead is
implanted in the atrium
or ventricle, depending
on the chamber to be
paced and sensed

39. DisadvantagesAdvantages
Advantages and Disadvantages of Single-Chamber
Pacing Systems
Implantation of a
single lead
Single ventricular lead
does not provide AV
synchrony
Single atrial lead does
not provide ventricular
backup if A-to-V
conduction is lost

40. • One lead
implanted in the
atrium
• One lead
implanted in the
ventricle
Dual-Chamber Systems Have Two Leads:

41. Benefits of Dual Chamber Pacing
• Provides AV synchrony
• Lower incidence of atrial fibrillation
• Lower risk of systemic embolism and stroke
• Lower incidence of new congestive heart failure
• Lower mortality and higher survival rates

43. 43
Examples
VVI
V: Ventricle is the paced chamber
V: Ventricle is the sensed chamber
I: Inhibited response to a sensed
signal
Thus, a synchronous generator that paces
and senses in the ventricle
Inhibited if a sinus or escape beat occurs
Called a “demand” pacer

44. 44
Examples
DVI
D: Both atrium and ventricle are
paced
V: Ventricle is sensed
I: Response is inhibited to a
sensed
ventricular signal

45. Examples
• DDDRA
• Dual chamber, adaptive-rate pacing with multisite
atrial pacing (i.e., biatrial pacing, more than one
pacing site in one atrium,or both features)
45

46. • Lead impedance
• Amplitude and pulse width setting
• Percentage paced vs. intrinsic events
• Rate responsive modes programmed “ON”
Factors That Affect Battery
Longevity Include:

47. Impedance Changes Affect Pacemaker
Function and Battery Longevity
• High impedance reading reduces battery current drain
and increases longevity
• Low impedance reading increases battery current drain
and decreases longevity
• Impedance reading values range from 200 to 2000 W
– High impedance leads will show impedance reading values
greater than 2000 ohms

48. A Pacemaker Must Be Able to Sense
and Respond to Cardiac Rhythms
• Accurate sensing enables the pacemaker to determine
whether or not the heart has created a beat on its own
• The pacemaker is usually programmed to respond with a
pacing impulse only when the heart fails to produce an
intrinsic beat

49. Accurate Sensing...
• Ensures that undersensing will not occur –
the pacemaker will not miss P or R waves that
should have been sensed
• Ensures that oversensing will not occur – the
pacemaker will not mistake extra-cardiac activity
for intrinsic cardiac events
• Provides for proper timing of the pacing pulse – an
appropriately sensed event resets the timing
sequence of the pacemaker

50. Pacemaker Timing
• Pacing Cycle : Time between two consecutive events in
the ventricles (ventricular only pacing) or the atria (dual
chamber pacing)
• Timing Interval : Any portion of the Pacing Cycle that is
significant to pacemaker operation e.g. AV Interval,
Ventricular Refractory period

52. Single Chamber Timing Terminology
• Lower rate
• Refractory period
• Blanking period
• Upper rate

53. Lower Rate Interval
Lower Rate Interval
VP VP
VVI / 60
• Defines the lowest rate the pacemaker will pace

54. Refractory Period
Lower Rate Interval
VP VP
VVI / 60
• Interval initiated by a paced or sensed event
• Designed to prevent inhibition by cardiac or
non-cardiac events
Refractory Period

55. Lower Rate Interval
Lower Rate Interval
VP VP
VVI / 60
• Defines the lowest rate the pacemaker will pace

56. Blanking Period
Lower Rate Interval
VP VP
VVI / 60
• The first portion of the refractory period
• Pacemaker is “blind” to any activity
• Designed to prevent oversensing pacing stimulus
Blanking Period
Refractory Period

57. Upper Sensor Rate Interval
Lower Rate Interval
VP VP
VVIR / 60 / 120
• Defines the shortest interval (highest rate) the pacemaker
can pace as dictated by the sensor (AAIR, VVIR modes)
Blanking Period
Refractory Period
Upper Sensor Rate
Interval

58. Dual Chamber Timing Parameters
• Lower rate
• AV and VA intervals
• Upper rate intervals
• Refractory periods
• Blanking periods

59. Lower Rate Interval
AP
VP
AP
VP
Lower Rate
• The lowest rate the pacemaker will pace the atrium in the absence of intrinsic
atrial events
DDD 60 / 120

60. AP
VP
AS
VP
PAV SAV
200 ms 170 ms
Lower Rate Interval
AV Intervals
• Initiated by a paced or non-refractory sensed atrial event
– Separately programmable AV intervals – SAV /PAV
DDD 60 / 120

61. Lower Rate Interval
AP
VP
AP
VP
AV Interval VA Interval
Atrial Escape Interval (V-A Interval)
• The interval initiated by a paced or sensed ventricular
event to the next atrial event
DDD 60 / 120
PAV 200 ms; V-A 800 ms
200 ms 800 ms

62. DDDR 60 / 120
A-A = 500 ms
AP
VP
AP
VP
Upper Activity Rate Limit
Lower Rate Limit
V-APAV V-APAV
Upper Activity (Sensor) Rate
• In rate responsive modes, the Upper Activity Rate provides
the limit for sensor-indicated pacing

63. AS
VP
AS
VP
DDDR 60 / 100 (upper tracking rate)
Sinus rate: 100 bpm
Lower Rate Interval {
Upper Tracking Rate Limit
Upper Tracking Rate
SAV SAVVA VA
• The maximum rate the ventricle can be paced in response
to sensed atrial events

64. Post Ventricular Atrial
Refractory Period (PVARP)
Refractory Periods
• VRP and PVARP are initiated by sensed or paced
ventricular events
– The VRP is intended to prevent self-inhibition such
as sensing of T-waves
– The PVARP is intended primarily to prevent
sensing of retrograde P waves
AP
VPVentricular Refractory Period
(VRP)
A-V Interval
(Atrial Refractory)

65. Post-Ventricular Atrial Refractory Period
PVARP is initiated by a ventricular
event(sensed/paced), but it makes the atrial
channel refractory
PVARP is programmable (typical settings around
250-275 ms)
Benefits of PVARP
– Prevents atrial channel from responding to
premature atrial contractions, retrograde P-
waves, and far-field ventricular signals
– Can be programmed to help minimize risk of
pacemaker-mediated tachycardias

66. Blanking Periods
• First portion of the refractory period-sensing is disabled
AP
VP
AP
Post Ventricular Atrial
Blanking (PVAB)
Post Atrial Ventricular
Blanking
Ventricular Blanking
(Nonprogrammable)
Atrial Blanking
(Nonprogrammable)

67. PVARP
Upper Tracking Rate
Lower Rate Interval
{No SAV started for events sensed in the TARP
AS AS
VPVP
SAV = 200 ms
PVARP = 300 ms
Thus TARP = 500 ms (120 ppm)
DDD
LR = 60 ppm (1000 ms)
UTR = 100 bpm (600 ms) SAV
TARP
PVARP
Total Atrial Refractory Period (TARP)
• Sum of the AV Interval and PVARP
• defines the highest rate that the pacemaker will
track atrial events before 2:1 block occurs
SAV

68. Fixed Block or 2:1 Block
• Occurs whenever the intrinsic atrial rate
exceeds the TARP rate
• Every other atrial event falls in the TARP
when the atrial rate exceeds the TARP
rate
• Results in block of atrial intrinsic events in
fixed ratios

69. Techniques of Permanent Pacemaker Implantation
Equipments
The pacemaker implantation can be performed in
electrophysiology (EP) laboratory cath lab,or operating
room Pacemaker implantation by interventional
electrophysiologist or cardiologist in EP lab or cathlab .
For pacemaker implantation consist of implanting
physician, scrub nurse, and circulating nurse, CRM
Cosultent .
Fluoroscopy and electrocardiography (ECG) are necessary
equipments in every device implant.

70. Initial lead sensing and
capture measurements are
obtained by pacing system
analyzers (PSA) &
Programmer.

71. Number of sterile surgical
instruments and equipment
that are needed .
Suture materials, material
for lead and device
anchoring and absorbable
material for pocket closure.

72. Patient preparation
Before pacemaker implantation, an informed consent
should be obtained. Any anticipatedrisks and benefits
should be honestly discussed with patient or the patient’s
family. The indication for pacing should be thoroughly
described to the patient. The need for lifelong follow-up
should be emphasized and patient should be informed
about the generator change and possible lead
replacement in the future. Any physical or occupational
restrictions related to the pacemaker implantation
including rules regarding the driving should be discussed
in detail with the patient.

73. • Routine pre-implant lab tests
• 12-lead ECG,
• Chest x-ray,
• Complete blood count,
• Serum electrolytes,
• Blood urea nitrogen
• Many of the patients requiring In the past, standard
practice was to discontinue warfarin 48 hours before
the procedure

74. Implantation of pacemaker
usually involves a combination
of local anesthesia conscious
sedation of skin and
subcutaneous tissue.
Implant area should be
completely clean and shaved.
chest is prepared with an
antiseptic solution, and the
area is covered with sterile
drapes to keep the incision
area as clean as possible.

75. Implant techniques
Central venous access
techniques
A central vein the subclavian or
internal jugular is accessed via
a hit and trial approach.
Alternatively, target vein is
accessed via direct visualization
by a cut down technique (most
commonly, cephalic vein).

76. Contrast venography performed from left brachial vein. The
figure clearly shows axillary vein, cephalic vein, subclavian
vein

77. Prepackaged Introducer Set for Implantation
implantation introducer kit consist of

78. Pocket formation
The most common site is the
pectoral region. In the latter
approach, a 1.5-to 2-inch
incision is made in the
infraclavicular area parallel
to the middle third of the
clavicle, and a
subcutaneous pocket is
created with sharp and blunt
dissection where the
pacemaker generator will be
implanted

79. Positioning of atrial and ventricular leads
Over the guide wire, a
special peel-away sheath
and dilator are advanced.
The guide wire and
dilator are withdrawn,
leaving the sheath in
place. A stylet (a thin
wire) is inserted inside
the center channel of the
pacemaker lead to make
it more rigid,

80. and the lead-stylet
combination is then
inserted into the sheath
and advanced under
fluoroscopy to the
appropriate heart
chamber. Usually, the
ventricular lead is
positioned before the
atrial lead to prevent its
dislodgment.

81. Lead connection and pulse generator insertion in the
pocket
Pocket closure
Post-procedural care