By
Dr Saqib Mahmud
MRCP(UK) MRCP(London) MRCGP
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Rate – normal, tachycardia or bradycardia
Rhythm – sinus or irregular
P waves present (II & V1 best leads to assess)
PR interval
QRS complexes & axis- widened QRS, Q
waves, buddle branch block, voltage criteria
for LVH
ST segments – isoelectric, depression or
elevation
T waves – N, peaked or inverted
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What was the indication?
age
Symptoms-CP, palpitations, sob, syncope,
dizziness
Haemodynamically stable?
Clinical signs- HF, poor peripheral perfusion
Pre-morbid Hx-HTN, IHD, DM, CKD
Medications- b-blockers, diltiazem etc
Consider repeating for interval change
Compare with previous ECG if available
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LVH – sum of S in V1 & R in V5 or V6 >35
RBBB – tall R in V1, QRS >0.12sec, R’sR
pattern
LBBB - QS-V1,V2, QRS>0.12
Axis - Axis leads-I&III or I&aVF, Normal axis-
“double thumbs up’’(I&III+), RAD I –ve, III +ve, LAD I +ve, III –ve
Inferior leads-------------II, III, aVF
Antero-septal leads------V1,V2,V3&V4
Antero-lateral leads------I,aVL,V5,V6
Heart rate calculation-(rhythm regular) count the no of large squares
b/w 2 consecutive QRS & divide into 300.HR=300/?
Irregular – count no QRS in 30 large squares X 10
RBBB
LBBB
Thumbs up!
Normal axis
RAD
LAD
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Sinus bradycardia
Sick sinus syndrome
2nd or 3rd degree/CHB
Escape rhythms- form of safety net to
maintain heart beat if impulse generation
fails or blocked
Negatively chronotropic drugs – betablockers(don’t forget eye drops!), Ca
antagonist; diltiazem, verapamil, digoxin
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Dizziness
Syncope
Recurrent falls in elderly
Fatigue
Breathlessness
CP
Palpitations
O/E-look for hypotension, signs of HF & poor
perfusion
Relevant Investigations – U&Es , TFTs
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Narrow complex (<3 small squares)
Broad complex (>3 small squares)
Narrow complex tachycardias always
supraventricular in origin
Narrow complex tachycardias:
Sinus tachycardia
Atrial fibrillation
Atrial flutter
AV nodal re-entrant tachycardia
Occurs if normal electrical impulses are
abnormally or aberrantly conducted to the
ventricles causing delay in ventricular
activation & widening of QRS complex
 VT
 Torsades de pointes
 Accelerated idioventricular rhythm
 SVT with aberrant conduction
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Tachycardia causing hemodynamic
disturbance requires urgent Rx
 Evidence of hemodynamic disturbance;
 Hypotension
 Cardiac failure
 Poor peripheral perfusion
 Investigations
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FBC
U&Es
TFTs
BNP
Hypothermia
 Hypothyroidism
 B-blockade
 Raised ICP
 Obstructive jaundice
 Uraemia
 Increased vagal tone
 Ischemia
 Structural SA node
disease
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Sinus bradycardia
Thyrotoxicosis
 Any cause of
adrenergic stimulation
including pain
 Hypovolaemia
 Anaemia
 Pregnancy
 Fever
 Myocarditis
 drugs;theophylines,salbut
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amol, vasodilator
antihypertensives
Sinus tachycardia
Is it regular or irregular?
 Regular rhythms
 Sinus rhythm- P waves precedes every QRS
complex with consistent PR interval
 Nodal or junctional rhythm- no P wave
preceding QRS complex but narrow regular
complexes
 Atrial flutter-saw tooth appearance, rapid &
regular with a rate about 150bpm(2:1 block)
 SVT, AVNRT-if high rate 150-220bpm
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Sinus arrhythmia-P wave precedes QRS with
constant PR interval but irregular
The end
Thank you