Download Basics of Pacing - St. Joseph Mercy Health System

Basics of Pacing
Ruth Hickling, RN-BSN
Tasha Conley, RN-BSN
The Cardiac
Conduction
System
Cardiac Conduction System Review
Normal Conduction
Conduction
QRS
QRS
Complex
Complex
RR
PP
ST
ST
segment
segment
PR
PR
segment
segment
PR Interval
PR Interval
Q
Q
ST interval
ST interval
SS
QT Interval
QT Interval
TT
Indications for Pacing
Documented evidence of Arrhythmia and Symptoms
Symptomatic Bradycardia
Sick Sinus Syndrome (AKA tachy/brady)
Sinus Arrest or Sinoatrial (SA) Exit Block
Atrial Fibrillation with slow V response or
s/p AVNA for AF with RVR
• Atrioventricular Block
• First Degree (symptomatic)
• Second Degree, Mobitz I and II
• Third Degree or Complete Heart Block
• Carotid Sinus Hypersensitivity/Syncope
•
•
•
•
Possible Symptoms
 Syncope
Dizziness
Confusion
Fatigue
Shortness of Breath
Limited Exercise Tolerance
Keeping it Simple
If the Sinus Node
Doesn’t Fire…
… then we need
to pace the atrium
Keeping it Simple
If the AV node
does not
appropriately
conduct…
...then we need to
pace the ventricle
In a ‘Nut Shell’
Pacemakers
1. Keep the heart from going too slow
2. Provide AV Synchrony
3. Aid in Chronotropic response
Indications for ICD Implantation
Primary Prevention
• Congenital Heart
Disease
• Long QT Syndrome
• Cardiomyopathy that
meets appropriate
NYHE guidelines
Ischemic
Non-Ischemic
Idiopathic
Hypertrophic
Secondary Prevention
• Prior Cardiac Arrest
• Ventricular
Tachycardia
• Ventricular
Fibrillation
What makes up a
Pacemaker / AICD
System?
Basic Components of
Pacing/AICD System
• Pulse Generator
•
•
•
•
Battery
Circuitry
Case
Header
• Lead(s)
• Systems can have up to
three leads depending on
implant indication
Pacemaker
Components of a pacemaker pulse
generator. Also called “the Can”
“Brain”
Single-Chamber
System
• The pacing lead is
implanted in the atrium
or ventricle, depending
on the chamber to be
paced and sensed
Dual Chamber
Systems
Have Two Leads
• One in the atrium
• One in the ventricle
Biventricular
Pacing Systems
Also called Cardiac Resynchronization
Therapy (CRT) pacemakers have
 a Right ventricular lead and a left
ventricular lead.
 These leads force the ventricles
to contract at the same time for
“resynchronization”
 May not have atrial lead with
history of chronic atrial fibrillation
Implantable Cardiac
Device Function and
Programming
Sensing
What the device “sees”
• Monitor the hearts intrinsic electrical activity
Think of a fence…
“Can’t see the hearts activity?!?”,
(Undersensing)
“Sees too much!”
(Oversensing)
EMI, Myopotential
“Ahhh, Just Right!”
(Appropriate sensing)
Pacing
The delivery of an electrical impulse to elicit contraction
of the heart muscle.
CAPTURE THRESHOLD – minimum amount of energy
needed to elicit contraction of the heart.
• Amplitude – How much energy (measured in Voltage)
• Pulse Width – Over what time period (measured in ms)
Voltages are set to 2 times the
amplitude of capture threshold to
ensure safety
Pacing Parameters
Lower Rate Limit (LRL):
Nominal - 60bpm
Rest rate – 50bpm
Pts with AF s/p AVNA 80bpm for 6 weeks
PVCs
Upper Rate Limit (URL): How fast device will pace
Patient can have OWN intrinsic rates higher that
programmed URL
Sensors – Rate Response
(Not to be confused with “sensing”)
Provide appropriate increase in heart rate with
activity for the those patients who have chronotropic
incompetence
“Accelerometer”
• Spring board system
• Measures heal strike
“Physiologic”
• Only available in pacemakers
• CLS (closed loop system)
• Minute Ventilation – not
appropriate for patient’s on a
ventilator
Magnet Response
Pacemakers
• “Shuts the eyes of the
pacemaker” (Sensing)
• Force A/V pacing at a
specific rate, which is
dependent on the pacemaker
manufacturer
(Ranging between 85-100bpm)
ICDs
• Temporarily deactivates
ICD therapies
Basic Differences between
Pacemakers and Defibrillators
Pacemakers
 Maintain HR, CO and
AV synchrony
 Pace at a specified rate
when magnet is applied
 Are not defibrillators
 They do not stop fast
heart rates
Defibrillators
 All have pacemaker
component, but may not be
utilized if no pacing
indication
 Treat sustained VT/VF with
pacing (ATP) and or shocks
 Magnet application suspends
detection for VT/VF and
prevents treatment. It does
not affect Pacing rates.
Keeping it Simple
• ICDs are intended to treat potentially
life threatening arrhythmias.
• ICDs can function as a Pacemaker
when pacing is indicated.
NBG Code
NASPE/BPEG Generic
I
II
III
IV
V
Chamber(s)
Paced
Chamber(s)
Sensed
Mode(s) of
Response
Programmable
Functions
Antitachycardia
Functions
A = Atrium
A = Atrium
T = Triggered
R = Rate
Modulated
P = Paced
V = Ventricle
V = Ventricle
I = Inhibited
C=
Communicating
S = Shocks
D = Dual
(A&V)
D = Dual
(A&V)
D = Dual
M=
D = Dual
(P&S)
O= None
O = None
O = None
Multiprogrammable
P = Simple
Programmable
O = None
O = None
Common Pacing Modes
Single Chamber
• VVI
• VVIR
• AAI
• AAIR
Dual Chamber
• DDD
• DDDR
• DDI
• DDIR
VVIR
V: ventricle is paced
V: ventricle is sensed
I: pacing is inhibited in response to a sensed event
R: rate responsive
This is a ventricular demand mode with artificial rate
response
D D DR
D: both chambers are paced
D: both chambers are sensed
D: pacemaker will either inhibit or trigger in
response to a sensed event
R: rate responsive
This is a dual chamber “universal” mode with
artificial rate response
Four Faces of DDD Pacing
Atrial pace - Ventricular pace
Atrial pace - Ventricular sense
Atrial sense - Ventricular sense
Atrial sense - Ventricular pace
DDD Pacing Example
Atrial Pace – Ventricular Pace
DDD Pacing Example
Atrial sense - Ventricular pace
“Atrial tracking”
DDD Pacing Example
Atrial Pace – Ventricular Sense
Could this be normal DDD
Pacemaker Function?
Normal sinus rhythm with no pacing
YES!
What About This?
Atrial Flutter with Variable V rate
Absolutely!
Identifying
Pacemaker/ICD
Related Issues
What do you see?
Capture
Loss
ofOf
Capture
Loss
Capture
What do you see?
Loss Of
Capture
Undersensed
QRS
Undersensing
More Undersensing
undersensing
Typical Paced Beat
Normal and Psuedofusion look the same
Pseudofusion
Fusion beats can have several
different looks
Helpful steps to take when calling
for trouble shooting assistance
• Make sure the telemetry monitor is not undersensing
beats such as a PVC.
• Make sure the “pacing spikes” are not artifact
• Please save copies or telemetry strips for questionable
rhythms.
• Often we can determine if device functionality is
an issue just by looking at these.
• Whenever possible, make sure to save 2 ECG
channels.
New Advancements in the
World of Cardiac Devices
Implantable Loop
Recorders
Implantable Loop Recorder
A Smaller version
The Evolution of Pacemakers
Then
Now
Leadless Pacemakers
Progression of ICDs
Subcutaneous ICD
It is always a good idea to have device settings
posted above the head of the bed.
• Device settings can be obtained from the cardiac rounding
nurse
• Signs for posting should be located at central stations on
your unit
• Essential information
 lower and upper rate limits for pacing
 Intervention rates for VT and VF
Need Help? Questions or Concerns?
Page the Pacemaker Nurse
(734) 670-1825
Available M-F 8am to 5pm
After hours page appropriate
company representative
P
Questions?!?
References
Biotronik (n.d.). Closed Loop Stimulation (CLS). Retrieved February 16, 2015 from
http://www.biotronik.com/wps/wcm/connect/en_us_web/biotronik/sub_top/
healthcareprofessionals/products/bradycardiatherapy?p=http://www.biotr
onik.com/wps/wcm/connect/en_us_web/biotronik/sub_top/healthcareprofes
sionals/products/bradycardiatherapy/closed_loop_stimulation/page_closed
_loop_stimulation&pw=974&pt=
Boston Scientific. (2011). Restoring Appropriate Rate for Chronotropic Incompetence. Retrieved February 16,
2015 from http://www.chronotropic- incompetence.eu/en/treatment-of-chronotropic-incompetence
Kutalek, S., Sharma, A., McWilliams, M., Wilkoff, B., Leonen, A., Hallstrom, A., & Kudenchuk, P. (2008).
Effect of pacing for soft indications on mortality and heart failure in the dual chamber and VVI
implantable defibrillator (DAVID) trial. Pacing & Clinical Electrophysiology, 31(7), 828-837
Medtronic, (2013). Clinical gudelines and inidcations. Retrieved February 16, 2015 from
http://www.medtronic.com/for-healthcare-professionals/products-therapies/cardiacrhythm/therapies/tachyarrhythmia-management/clincial-guidelines-indications/
The NBG Code, (n.d.). The NBG Code: NASPE?BEPG generic. Retrieved February 16, 2015 from
http://www.pacemaker.vuurwerk.nl/info/nbg_code__naspe.htm