Download 2014 PowerPoint Template Standard

ECG Basics &
Cardiac Troubleshooting
Lance Lennon
Product & Applications Specialist - CT
March 2016
Outline
1. ECG Basics
2. Rhythms & Arrhythmias
3. Scan Techniques
4. ECG Editing Hot Cases!
3
Outline
1. ECG Basics
2. Rhythms & Arrhythmias
3. Scan Techniques
4. ECG Editing Hot Cases!
4
1. ECG Basics
The heart contracts when pumping blood and rests when
receiving blood.
This activity and lack of activity from a cardiac cycle can be
illustrated by an electrocardiogram (ECG).
5
1. ECG Basics
An ECG is the recording of the electrical activity of the heart
Information obtainable from an ECG includes;
Heart Rate
Yes
Rhythm / Regularity
Yes
Impulse Conduction Time Intervals
Yes
Abnormal Conduction Pathways
Yes
Pumping Action
No
Cardiac Output
No
Blood Pressure
No
Cardiac Muscle Hypertrophy
No
6
1. ECG Basics
7
1. ECG Basics
P-wave
SA node fires and sends electrical impulse outward to stimulate both
atria and manifests as a P-wave
Approximately 0.1sec in length
8
1. ECG Basics
PR Interval
Time in which impulse travels from the SA node to the atria and
downward to the ventricles
9
1. ECG Basics
QRS Complex
Impulse from the bundle of HIS throughout the ventricular muscles
Measures less than 0.12sec or less than three small squares on the
ECG paper
10
1. ECG Basics
T-wave
Ventricular repolarisation meaning no associated activity of the
ventricular muscle
Resting phase of the cardiac cycle
11
1. ECG Basics
Lazy ECG electrode setup lead to suboptimal results
This is my pet peeve! Lazy setup!
12
1. ECG Basics
Lazy ECG electrode setup lead to suboptimal results
Exposure can interfere with ECG signal
13
1. ECG Basics
Lazy ECG electrode setup lead to suboptimal results
Exposure can interfere with ECG signal
14
1. ECG Basics
Lazy ECG electrode setup lead to suboptimal results
Leads touching gantry
R peak
R peak
Interference
Every 0.35sec
15
1. ECG Basics
Lazy ECG electrode setup lead to suboptimal results
Exposure can interfere with ECG signal
16
1. ECG Basics
Careful patient preparation is the key to a successful cardiac
scan.
If the following procedure is followed for every cardiac case,
abnormal ECG signals are very rare.
It is critical to ensure good contact between the electrode
and the skin.
17
1. ECG Basics
Place the ECG electrodes on the patient’s chest using the guide below.
Skin Preparation is useful to clean and abrade the skin to ensure good
electrode contact. Shaving may be necessary when there is extensive
chest hair.
The electrodes must be outside the primary radiation beam (CABG is the
only exception)
18
1. ECG Basics
Perform an Impedance Test on the ECG monitor to ensure good
electrode contact.
Press the Measure Impedance button.
The results are displayed on the monitor. Any lead with impedance
that shows red (over 50kΩ) must be adjusted.
Move the electrodes and clean the skin to improve contact.
Only proceed when the impedance test results show blue
19
1. ECG Basics
Confirm that the R-peaks are taller than the P and T waves. Adjust the
lead settings on the ECG monitor to change the active lead to Lead I, II or
III.
Ensure the ECG cables are not touching the gantry.
Move the ECG monitor away from the gantry and the injector.
Confirm that a clean ECG signal is displayed before continuing!
20
1. ECG Basics
21
Outline
1. ECG Basics
2. Rhythms & Arrhythmias
3. Scan Techniques
4. ECG Editing Hot Cases!
22
2. Rhythms & Arrhythmias
Types of rhythms
Rate:
Bradycardia = rate of <60bpm
Normal = rate of 60-100bpm
Tachycardia = rate of >100-160bpm
Where it is coming from:
Sinus = SA node
Atrial = SA node fails, impulse comes from the atria (internodal or
the AV node)
Ventricular = SA or AV fails, ventricles will pace the heart
23
2. Rhythms & Arrhythmias
Sinus rhythms
Normal sinus rhythm (NSR)
What is the rate?
60-100bpm
What is the rhythm?
Atrial or Ventricular rhythm and regular
Is there a P wave before each QRS?
Yes
Are the P waves upright and uniform?
Yes
What is the length of the PR interval?
0.12-0.2sec (3-5 small squares)
Do all the QRS complexes look alike?
Yes
The length of the QRS complexes is…?
Less than 0.12sec (3 small squares)
24
2. Rhythms & Arrhythmias
Sinus rhythms
Sinus bradycardia rhythm
What is the rate?
Less than 60bpm
What is the rhythm?
Atrial or Ventricular rhythm and regular
Is there a P wave before each QRS?
Yes
Are the P waves upright and uniform?
Yes
What is the length of the PR interval?
0.12-0.2sec (3-5 small squares)
Do all the QRS complexes look alike?
Yes
The length of the QRS complexes is…?
Less than 0.12sec (3 small squares)
25
2. Rhythms & Arrhythmias
Sinus rhythms
Sinus tachycardia rhythm
What is the rate?
100-160bpm
What is the rhythm?
Atrial or Ventricular rhythm and regular
Is there a P wave before each QRS?
Yes
Are the P waves upright and uniform?
Yes
What is the length of the PR interval?
0.12-0.2sec (3-5 small squares)
Do all the QRS complexes look alike?
Yes
The length of the QRS complexes is…?
Less than 0.12sec (3 small squares)
26
2. Rhythms & Arrhythmias
Atrial rhythms
SA node fails to generate an impulse. The atrial tissue or areas of the
internodal pathways may initiate an impulse
These are called atrial arrhythmias or dysrhythmias
Generally not considered life threatening
Careful patient management must be ongoing
27
2. Rhythms & Arrhythmias
Atrial rhythms
Atrial fibrillation
What is the rate?
Atrial 350-400bpm
What is the rhythm?
Irregular
Is there a P wave before each QRS?
Normal P waves are absent
Are the P waves upright and uniform?
Replaced by F waves
What is the length of the PR interval?
Not measurable
Do all the QRS complexes look alike?
Yes
The length of the QRS complexes is…?
Less than 0.12sec (3 small squares)
28
2. Rhythms & Arrhythmias
Ventricular rhythms
SA node or the AV tissue fails to initiate an impulse, ventricles will
pace the heart
These are called ventricular arrhythmias or dysrhythmias
Electrical impulse can be initiated from any pacemaker cell in the
ventricles including the bundle braches or Purkinje fibres
29
2. Rhythms & Arrhythmias
Ventricular rhythms
Premature ventricular complex/contraction (PVC)
What is the rate?
Dependent on rate and number of PVCs
What is the rhythm?
Regular, occasionally irregular
Is there a P wave before each QRS?
No P waves associated with PVC
Are the P waves upright and uniform?
P waves of underlying rhythm may be present
What is the length of the PR interval?
Not present
Do all the QRS complexes look alike?
Wide and bizarre
The length of the QRS complexes is…?
Less than 0.12sec (3 small squares)
30
2. Rhythms & Arrhythmias
Asystole… quickly scan as heart is not moving!
What is the rate?
Absent
What is the rhythm?
Absent
Is there a P wave before each QRS?
No
Are the P waves upright and uniform?
Not identifiable
What is the length of the PR interval?
Not present
Do all the QRS complexes look alike?
Not present
The length of the QRS complexes is…?
Not present
31
2. Rhythms & Arrhythmias
Artificial pacemaker
What is the rate?
Varies according to preset rate of pacemaker
What is the rhythm?
Regular if pacing fixed
Irregular if demand paced
Is there a P wave before each QRS?
Maybe, depends on pacemaker
Are the P waves upright and uniform?
Maybe, depends on pacemaker
What is the length of the PR interval?
Variable, depends on pacemaker
Do all the QRS complexes look alike?
Usually
The length of the QRS complexes is…?
Greater than or equal to 0.12sec. Look bizarre
32
Outline
1. ECG Basics
2. Rhythms & Arrhythmias
3. Scan Techniques
4. ECG Editing Hot Cases!
33
3. Scan Techniques
After Breath Exercise on Aquilion PRIME, check the following;
kVp
Phase selection is appropriate for HR
After Breath Exercise on Aquilion ONE & ViSION, check the
following;
kVp
Number of beats for acquisition is appropriate (can over ride)
Phase selection is appropriate for HR
34
3. Scan Techniques
What if this happens before Calcium Score scan?
35
3. Scan Techniques
What if this happens again?
36
3. Scan Techniques
If HR is high (>75bpm) and regular?
Trust SURECardio settings
PRIME will typically recommend Retrospective
ONE & ViSION will typically recommend multiple beat scanning
37
3. Scan Techniques
If HR is irregular?
Trust Arrhythmia Rejection
PRIME may recommend Retrospective. Can change to Prospective and
trust Arrhythmia Rejection
ONE & ViSION may recommend multiple beat scanning. Can force
acquisition to single beat as only one good beat needed. If multiple
beat scanning selected, more normal beats required…
38
3. Scan Techniques
Electrophysiology (EP) planning
Only interested in left atrium and pulmonary veins
Not interested in coronary arteries
Patients often in AF (reason for procedure)
Single beat scan (force if necessary)
Can use Target CTA or Prospective CTA scan mode
Target phase 40% (systole)
For information on the procedure and ablation;
http://en.wikipedia.org/wiki/Electrophysiology_study
39
Outline
1. ECG Basics
2. Rhythms & Arrhythmias
3. Scan Techniques
4. ECG Editing Hot Cases!
40
4. ECG Editing Hot Cases!
What if this happens after scan?
41
4. ECG Editing Hot Cases!
42
4. ECG Editing Hot Cases!
ECG Save Image Aquilion PRIME
Exposure
Couch
position
HR during
Breath Exercise
Reconstruction
Needs to fit within
grey exposure
window.
Pitch set by
Breath Exercise
Where scanner
has identified Rpeak. Can be
moved.
Cardiac Phase selected
Following Breath Exercise
Minimum, maximum and mean
HR during actual scan
eg. 60000 ÷1243=48bpm
43
4. ECG Editing Hot Cases!
ECG Save Image Aquilion ONE & ViSION
Number of
beats selected
HR during
following Collimation
Breath Exercise
Breath Exercise
Cardiac Phase selected
Following Breath Exercise
Exposure
Reconstruction
Needs to fit within
grey exposure
window.
Where scanner
has identified Rpeak. Can be
moved.
Minimum, maximum and mean
HR during actual scan
eg. 60000 ÷1398=42bpm
44
4. ECG Editing Hot Cases!
Case 1
AqONE, 58-60bpm during Breath Exercise, 1 beat scan 70-80%
? Cause
? Fix
45
4. ECG Editing Hot Cases!
Case 2
Aquilion PRIME
? Cause
? Fix?
46
4. ECG Editing Hot Cases!
Case 2
Aquilion PRIME
What about this as a fix?
47
4. ECG Editing Hot Cases!
Case 2
Aquilion PRIME
Don’t forget about using a R minus ms reconstruction
-200ms was the money shot and revealed plaque causing stenosis
48
Outline
1.
ECG Basics
Get a good trace! Impedance test! Impedance test!
2.
Rhythms & Arrhythmias
Show off what you know!
3.
Scan Techniques
Think about what you need and how to achieve
4.
ECG Editing Hot Cases!
Work logically. Photos are very useful!
49