ECG Analysis Flashcards
What are the inferior heart leads
Lead II
Lead III
AVF
What vessels is associated with the inferior heart leads
Right coronary artery
What are the anterolateral heart leads
Lead I
AVL
V5 and V6
What vessel is associated with the anterolateral heart leads
Left circumflex
What are the anteroseptal leads
V2-V4
What vessels is associated with anteroseptal node
Left anterior descending
What are the anterior ECG leads
V2-V6
What are the posterior ECG leads
V1, V2, V3 (Reciprocal)
What vessel is associated with the posterior ECG leads
Right coronary artery
What does the amplitude of the deflection indicate
Myocardial mass
What does the deflection width indicate
Conduction speed
When do we get a positive deflection
When the depolarisation is towards the positive lead
How do you calculate heart rate on an ECG
300/number of large squares between R waves
What is the normal axis of the heart
between -30 to +90
What is the axis in left axis deviation
-30 to -90
What is the axis in right axis deviation
+90 to +180
What causes right axis deviation
RVH and anterolateral MI
What causes left axis deviation
LVH and inferior MI
What does the P wave indicate
Atrial depolarisation
In which leads is the P wave positive normally
AVF
Lead I
Lead II
Lead III
Which lead is the P wave normally -ve in
AVR
What is a sinus arrhythmia
When there is abnormal rhythm in the SAN
What is the normal length of the P wave
120ms
An absent P wave is indicative of what conditions
Atrial fibrillation
SAN block
Nodal rhythm
A dissociated P wave is indicative of what
Heart block
A bifid P wave is indicative of what condition
P. Mitrale = LA hypertrophy
A peaked P wave is indicative of what condition
P.pulmonale = RA hypertrophy
Whatdoes QRS complex represent
Ventricular depolarisation
What conditions does a wide QRS complex suggest
Ventricular initiation
Conduction defect
Wolff Parkinson White
What does a pathological Q wave indicate
Full thickness MI
What does tall QRS complexes indicate
LVH
What is the length of a normal PR interval
120-200ms
What does a long PR interval indicate
Heart block
What does a short PR interval indicate
Accessory conduction (WPW) Nodal rhythm
What does a depressed PR interval indicate
Pericarditis
What is the normal QT interval
380-420ms
Define a prolonged QT interval
> 420ms
What are the causes of a prolonged QT interval (remember TIMME)
Toxins
- Macrolides
- Anti-arrhythmics (Quinidine)
- Histamine antagonists
INherited/Ischaemia
Myocarditis
Mitral valve prolapse
Electrolytes = decreased calcium
What causes a short QT interval
Digoxin
Beta blockers
Phenytoin
What causes the ST segment to be elevated
Acute MI
Prinzmetals angina
Pericarditis (Saddle shaped)
Aneurysm
What causes the ST segment to be depressed
Ischaemia
Digoxin
What are the features of 1st degree heart block
Prolonged PR interval (>200ms)
What are the features of 2nd degree heart block mobitz type I
Progressive lengthening of PR interval
One non conducted P wave
What features in 2nd degree heart block mobitz type II
Constant PR interval butoccasiondal non conducted P waves with often wide QRS
What features are seen in 2nd degree heart block 2:1 block
Two P waves per QRS
Normal consistent PR intervals
What features are seen in third degree heart block
P waves andQRS are completely dissociated
What are the features of right bundle branch block
MARROW
M in V1 = +ve
W in V6 = -ve
Wide QRS
What are the features of left bundle branch block
WILLIAM
W in V1 = -ve
M in V6 = +ve
What are the causes RBBB
Infarct
Normal variant
Congenital (ASD, VSD)
RVH
What are the causes of LBBB
Fibrosis LVH Infarct Coronary IHD Aortic valve disease Post cardiac surgery
