Transcript The Evolution of ICD Therapy:

Single Chamber
Temporary Pacing
Operations & Troubleshooting
Temporary Pacing Indications
Sick Sinus Syndrome
(Patient Must Be Symptomatic and Documented with ECG)

Symptomatic sinus bradycardia
 Symptomatic sinus arrest
 Suppression of ventricular ectopy resulting
from bradycardia
 Atrial fibrillation
 Bradycardia/Tachycardia syndrome
Temporary Pacing Indications
Heart Blocks

Type I and Type II second degree AV block
 Acute bifascicular or trifascicular block
 Complete AV block
 Cardiac arrest with ventricular asystole
Other Temporary Pacing Indications
Drug-Refractory Dysrhythmia
 Overdrive ventricular pacing to suppress
or prevent VEA (Ventricular Ectopic Activity)
 Overdrive atrial pacing to “break” SVT, atrial
flutter
Other Temporary Pacing Indications
Cardiovascular Surgery

Coverage for anesthesia and surgery in patients
with positive cardiac history
 Treatment for CHB development during surgery
 Augment cardiac output post operatively
Other Temporary Pacing Indications
Diagnostic Uses

SSS pacing studies to determine SA node recovery
 Stress testing for Coronary Artery Disease
 Electrophysiologic (EP) studies
Insertion Sites
Internal Jugular Vein
External Jugular Vein
Brachial Vein
Femoral Vein
Subclavian Vein
Lead Types
Lead Types
 Endocardial/Transvenous lead
– Transvenous lead is introduced into a vein
and advanced into the heart
 Epicardial/Myocardial lead
– An epicardial lead attached to the outside of
the heart is introduced through the chest wall
Lead Types
 Bipolar lead
system
– The negative
and positive
electrodes
are in contact
with the heart
Lead Types
 Unipolar lead
system
– The negative
electrode is in
contact with the
heart and the
positive (or ground)
electrode is located
elsewhere on the
body
Cable Connectors
 Connector pins on the
lead(s) must be fully
inserted in the patient
connector block
 Observe polarity
– Distal = negative
– Proximal = positive
 Finger tighten only –
no tools!
Temporary Pacing Parameters

Pacing rate (heart rate)
 Output/stimulation threshold
 Sensitivity
Pacing Rate
Paced Interval
Paced Interval
Output
Output Pulse
Output/Current
(ma)
Pulse Width
(ms)
 The output dial regulates the current or movement of electrons
Capture
Depolarization of cardiac muscle
following an electrical stimulus
Stimulation Threshold
The minimum output pulse needed
to consistently capture the heart
3 mA
2 mA
1 mA
Lead Maturation
Threshold Amplitude
x3
x2
Initial
1 2 3 4 5
10
Days Since Leads Applied
15
Sensitivity
The degree that the pacing system “sees” or senses signals,
controlled by the sensitivity setting which is graduated in
millivolts (mV)
Sensitivity (mV)
5 (mV)
2.5 (mV)
1.25 (mV)
Sensitivity
The lower the setting, the more sensitive
the pacemaker is to intracardial signals
NBG Codes
1st Letter
2nd Letter
Chamber(s) Paced
A = atrium
V = ventricle
D = dual (both atrium
and ventricle)
Chamber(s) Sensed
A = atrium
V = ventricle
D = dual
O = none
3rd Letter
Response to Sensing
I = inhibit
(Demand mode)
T = triggered
D = dual
O = none (Asynch)
Chamber paced
Chamber sensed
Action or response to a sensed event
V
V
I
VVI Demand/Inhibited
 Pacemaker senses intrinsic depolarization
 Paces the heart when the patient’s own rate
becomes slower than the pacemaker
Ventricular Inhibited Mode (VVI)
VOO Asynchronous (Fixed)
Pacemaker will emit an output at a fixed rate
regardless of intrinsic activity
Ventricular Asynchronous Mode (VOO)
Single Chamber Troubleshooting
Process
1.
Gather information
2.
Identify the problem and possible cause
3. Identify the solution and carry out
corrective procedures
Information Gathered
 Patient data
 Pacemaker information
 Lead information
 Non-invasive tools
Undersensing
Failure of the pacemaker to sense
intrinsic R-waves or intrinsic P-waves
Undersensing
Oversensing
Inhibition of the pacemaker by events the
pacemaker should ignore, e.g. EMI, T-waves,
and myopotential
Oversensing
Loss of Capture
Loss of Output
Fusion/Pseudofusion Beats
Intrinsic Beat
Intrinsic Beat
Fusion Beat
Fusion Beat
Paced Beat
Paced Beat
Pseudofusion Beat
Pseudofusion Beat
Electromagnetic Interference (EMI)
Radiated or conducted energy – either electrical
or magnetic – which can interfere with the
function of the pacemaker in the Demand mode
(EMI)
Should have
paced
2.5 mV
80
80