Back to Medical SchoolECG interpretation – made easy !
Dr Rob Sapsford
The Yorkshire Heart Centre
Leeds General Infirmary
ECG’s have become more convenient
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LV
RV
LA
RA
Lead error
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Lead error
Normal ECG
4 large squares
300/large squares = rate
Machine reported as “old inferior infarct”
Pathological Q-wave
•>25% r wave
•>1 small square across
Clinical context
Be wary of overly sensitive ECG machine computer reports
Incomplete RBBB
RBBB
LBBB
1.
QT interval
QT interval
Normal up to 12 small squares (dependent rate)
(0.450s)
QT Interval Calculation
TangentBaselin
e
QT
R-R interval
QT Interval = QT / R-R interval
Case studies
LVH (several criteria) simple rule:
Limb lead (I / AVL) – 12 mmHg >
Chest leads (V1 S + V5/6 R) => 35 mmHG
Atrial fibrillation – fast ventricular response
Sinus tachycardia
SOB 60 yr old woman
Left Bundle Branch Block
Intermittent palpitations at rest
Ventricular ectopy
1st degree AV block (heart block)
2nd degree AV block (Mobitz type II)
2:1 AV block
Exercise intolerant 73 yr old man
3rd degree AV block (complete heart block)
Atrial flutter with 2:1 block
AF and complete heart block
78 year old woman; chest pain yesterday
acute coronary syndrome- widespread ischaemia
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Chest pain - acute
Anterior septal acute coronary syndrome
Sharp chest pain worse lying flat
Pericarditis
Acute inferior ST elevation MI
Palpitations
Broad complex tachycardia
RVOT VT
Summary
• Review of ECG interpretation• Rate, Rhythm, (Axis) • P wave, QRS and relationship• Common pitfalls
• Can be difficult– The computer is overly sensitive, but can be helpful– Someone to discuss with is reassuring