ecgg interpretation
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ECGG Interpretation. Najib Ul Haq. ECG. ECG Basics Normal Sinus Rhythm How to Analyze a Rhythm Heart Arrhythmias Diagnosing a Myocardial Infarction Advanced 12-Lead Interpretation. Normal Cardiac Current Flow. Basics of Current movement. - PowerPoint PPT PresentationTRANSCRIPT
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ECGG Interpretation
Najib Ul Haq
ECG
• ECG Basics• Normal Sinus Rhythm• How to Analyze a Rhythm• Heart Arrhythmias• Diagnosing a Myocardial Infarction• Advanced 12-Lead Interpretation
Normal Cardiac Current Flow
Basics of Current movement
• Current + Electrode
• Electrode Current
Normal ECG
Normal Impulse ConductionSinoatrial node
AV node
Bundle of His
Bundle Branches
Purkinje fibers
Impulse Conduction & the ECGSinoatrial node
AV node
Bundle of His
Bundle Branches
Purkinje fibers
The PR Interval
Atrial depolarization +
Delay in AV junction (AV node/Bundle of His)
(Delay allows time for the atria to contract before the ventricles contract)
The “PQRST”
• P wave - Atrial depolarization
• T wave - Ventricular repolarization
• QRS - Ventricular depolarization
Normal ECG
Normal ECG
Lead Iextends from the right to the left arm
Lead IIextends from the right arm to the left foot
Lead IIIextends from the left arm to the left foot
Einthoven’s Triangle
+-
+
-
Diagnosing MI
To diagnose a myocardial infarction you need to go beyond looking at a rhythm strip and obtain a 12-Lead ECG.
Rhythm Strip
12-Lead ECG
The 12-Lead ECG
• The 12-Lead ECG sees the heart from 12 different views.
• Therefore, the 12-Lead ECG helps you see what is happening in different portions of the heart.
• The rhythm strip is only 1 of these 12 views.
The 12-Leads
The 12-leads include:–3 Limb leads
(I, II, III)
–3 Augmented leads (aVR, aVL, aVF)
–6 Precordial leads (V1- V6)
Views of the Heart
Some leads get a good view of the:
Anterior portion of the heart
Lateral portion of the heart
Inferior portion of the heart
ST Elevation
One way to diagnose an acute MI is to look for elevation of the ST segment.
192004 Anna Story
A Normal 12 Lead ECG
ST Elevation (cont)
Elevation of the ST segment (greater than 1 small box) in 2 leads is consistent with a myocardial infarction.
Left Main Coronary ArteryBranches quickly into the LAD & LCX. Involves almost 2/3 of the heart muscle primarily anterior
Right Coronary Artery (RCA) The RCA supplies blood to the bottom (inferior) portion and part of the back (posterior) portion of the left ventricle. The posterior portion of the septum is also supplied with blood from the RCA.
• SA Node 55%• AV Node 90%• AV Blocks
Left Anterior Descending Branch (LAD)The LAD supplies blood to the front (anterior) portion of the left ventricle, apical including most of the anterior portion of the septum separating the ventricles.•Bundle Branch Block, AMI, CHF
Left Circumflux Branch (LCX)The LCX supplies blood to the left side (lateral) portion and the back (posterior) portion of the left ventricle.
• SA Node 45% • AV Node 10%• Lateral & posterior MI
MI Locations
Look again at this picture of the heart.
Anterior portion of the heart
Lateral portion of the heart
Inferior portion of the heart
MI Locations
Look again at this picture of the heart.
Anterior portion of the heart
Lateral portion of the heart
Inferior portion of the heart
Anterior View of the Heart
The anterior portion of the heart is best viewed using leads V1- V4.
Anterior MI
Remember the anterior portion of the heart is best viewed using leads V1- V4.
Limb Leads Augmented Leads Precordial Leads
• Leads V3, V4– Looks at anterior heart wall– Looks from the left anterior chest
Anterior Wall MI
View of Anterior Heart Wall
Lateral MI
So what leads do you think the lateral portion of the heart is best viewed?
Limb Leads Augmented Leads Precordial Leads
Leads I, aVL, and V5- V6
• Leads I and aVL– Looks at lateral heart wall – Looks from the left arm toward
heart
Lateral Wall MI
View of Lateral Heart Wall
*Sometimes known as High Lateral*
Inferior MI
Now how about the inferior portion of the heart?
Limb Leads Augmented Leads Precordial Leads
Leads II, III and aVF
• Leads II, III, aVF- Looks at inferior heart wall
Inferior Wall MI
View of Inferior Heart Wall
- Looks from the left leg up
Putting it all Together
Now, where do you think this person is having a myocardial infarction?
Inferior Wall MI
This is an inferior MI. Note the ST elevation in leads II, III and aVF.
Inferior Wall MIThis is an inferior MI. Note the ST elevation in leads II, III and aVF.
Inferior Wall MI
Putting it all Together
How about now?
Anterolateral MI
This person’s MI involves both the anterior wall (V2-V4) and the lateral wall (V5-V6, I, and aVL)!
Thank You