Tools: ECG Flashcards
ECG. What do leads I, II and VL ‘look at’?
The left lateral surface of the heart.
ECG. What do leads III and VF ‘look at’?
The inferior surface of the heart.
ECG. What does lead VR ‘look at’
The right atrium.
ECG. What do leads V1 an V2 look at?
The right ventricle
ECG. What do leads V3 and V4 look at?
The septum between the ventricles.
ECG. What do leads V5 and V6 look at?
Anterior and lateral walls of left ventricle.
Which lead do you look at to show rhythm.
The one that shows the P wave most clearly: lead II.
Compare VR and lead II
They are opposite; VR is mostly negative, lead II mostly upward.
What is indicative of right axis deviation?
Lead I with a negative QRS complex, leads II and III with it positive.
What is indicative of left axis deviation?
Positive but small lead I QRS. Negative leads II and III
If the RR interval in large squares is 1, what is the HR?
300
If the RR interval in large squares is 2, what is the HR?
150
If the RR interval in large squares is 3, what is the HR?
100
If the RR interval in large squares is 4, what is the HR?
75
If the RR interval in large squares is 5, what is the HR?
60
If the RR interval in large squares is 6, what is the HR?
50
How wide is a normal QRS
about 3 small squares
Name the limb leads clockwise from VR
VR, VL, I, II, VF, III
What are the chest leads?
V1 - V6
What is a normal cause of left axis deviation?
Conduction defect.
What is a normal cause of right axis deviation?
Increased muscle bulk on the right side.
How to report an ECG
Name and date Rate and rhythm Conduction defects A description of QRS intervals ST segments and T waves.
When is the transition point in an ECG?
When the chest leads shift from being predominantly negative to predominantly positive e.g where R = S. It is normally at V3/V4
How does the transition point move in RV enlargement?
It shifts to V4/V5/V6
If there is a prolongued PR interval of greater than 5 small squares, what condition does this suggest, and what are the causes?
First degree heart block. Coronary artery disease, acute rheumatic carditis, digoxin toxicity and electrolyte disturbances.
What is it called when there is a progressive lengthening of the PR interval?
Mobitz type 1, second degree heart block, usually benign.
What is it called if most beats have a constant PR, but there is an extra p wave sometimes?
Mobitz type 2, which may herald third degree heart block.
What does an ECG with ST elevation in leads II, III and aVF and also in C5 and C6 suggest?
An inferolateral infarction
If there are ischaemic changes in leads I, aVL, and leads V2, V3 and V4, where is the ischaemia?
In the apex.
If there are ischaemic changes in leads V2 and V3 only, where is the ischaemia?
Anteroseptal: LAD
If there are ischaemic changes in leads I, aVL, and leads V5 and V6, where is the ischaemia?
anterolateral: left circumflex artery
If there are ischaemic changes in leads III and aVF, and leads V5 and V6, where is the ischaemia?
Posterolateral
If there are ischaemic changes in leads II, III and aVF, where is the ischaemia?
inferior - either right coronary artery or left circumflex (20%)
If there are ischaemic changes in leads III and aVF, and possibly V2, where is the ischaemia?
Right ventricle
Which are the lateral leads?
I, aVL, V5 and V6
Which are the inferior leads?
II, III and aVF
Which are the septal leads?
V1 and V2
Which are the anterior leads?
V3 and V4
Which artery is blocked in an anterior MI?
Left anterior descending.
Which artery is blocked in an septal MI?
Left anterior descending
Which artery is blocked in a lateral MI?
Left circumflex artery
Which artery is blocked in an inferior MI?
Right coronary artery (80%) or left circumflex (20%)
Which artery is blocked in an posterior MI?
RCA or LCX
Which artery is blocked in an right ventricle MI?
RCA
What does an ECG with ST elevation in leads II, III and aVF and also in C5 and C6, and ST depression in I and aVL?
A larger infero-lateral myocardial infarction.
What does an ECG with ST elevation and evolving Q waves in leads V1-4 suggest?
Acute anterior myocardial infarction.
What is the ECG change in a positive exercise stress test?
ST depression
Signs of angina on an ECG.
Usually normal, can show ST depression, flat or inverted T waves, signs of past MI.
ECG for Prinzmetal’s angina.
ST elevation during pain.
Classic ECG for an MI
Hyperacute T waves, ST elevation or new LBBB within hours, then T wave inversion and pathological Q waves over hours to days.
Saddle shaped ST segment signifies…
Pericarditis - although can also be normal ECG.
Cause of widespread PR depression
Pericarditis - most specific ECG marker
