ECG interpretation Dr. Shamim Nassrally BSc (Hons) MB ChB MRCP(UK) Clinical Teaching Fellow
Dec 24, 2015
ECG interpretation
Dr. Shamim NassrallyBSc (Hons) MB ChB MRCP(UK)
Clinical Teaching Fellow
Objectives
By the end of this session you should be able to:
Interpret ECGs using a systematic approach
Recognise important ECG abnormalities: acute coronary syndrome acute myocardial infarction common arrhythmias.
Framework
Basic information/Demographics Rate Rhythm Axis P wave and PR interval QRS complex ST segment
Basic information
Identifying information: name/unit number Date/time Voltage (10mm/mV) Speed (25mm/s)
Rate
300/number large squares
Normal: 60-100bpm <60 = bradycardia >100 = tachycardia
Rhythm Are there P-waves? Is each P followed by a QRS? Is each QRS preceded by a P wave?
AF/atrial flutter Supraventricular tachycardias Heart block:
1st degree 2nd degree (Mobitz type 1 and type 2) 3rd degree (complete heart block)
P wave and PR interval
Normal P wave <2.5mm high, <0.11s
Normal PR interval 0.12-0.2s (3-5 small squares)
Axis
I and II positive = normal axis I positive + III negative = left axis deviation I negative + III positive = right axis deviation
QRS complex
Normal QRS <0.12s (3 small squares)
LVH criteria
Wide QRS Left bundle branch block Right bundle branch block
ST segment
ST elevation: MI, left bundle branch block ST depression: ischaemia, posterior MI,
digoxin
T-wave: Tall – hyperkalaemia, left bundle branch block Flat – ischaemia, hypokalaemia
Quiz
Rate Rhythm P wave, PR interval Axis QRS complex ST segment T waves