ECG in GP By Prof.Dr.R.R.Deshpande

2

1. Introduction 5 to 10

2. Electric circuit of heart 11

3. Waves of ECG 12

4. Normal ECG of chest leads 13

5. ECG of I,II,III,aVR,aVL,aVF leads 14

6. Sinus Rhythm 15 & 16

7. Sinus Bradycardia 17 & 18

8. Sinus Tachycardia 19 to 21

9. Left Axis Deviation 22 & 23

10. Right Axis Deviation 24 to 26

Slide Number TITLE

3

11. Normal pattern of QRS complex 27

12. LVH 28 to 31

13. RVH 32 to 34

14. RAH 35 to 37

15. LAH 38 to 40

16. M.I 41 to 43

17. Angina 44 to 47

18. M.I 48 to 63

19. Stress Test 64 to 66

20. 1st Degree Heart block 67 to 69

21. Mobitz type 1 AV block 70 to 72

22. Mobitz type 2 AV block 73 to 75

4

23. 3rd Degree Heart block 76 to 78

24. 2:1 AV Block 79 to 81

25. LBBB 82 to 84

26. RBBB 85 to 87

27. Hyper Ca++ 88 to 90

28. Hypo Ca++ 91 to 93

29. Hyper Kalaemia 94 & 95

30. Hypo Kalaemia 96 & 97

31. Digoxin effect 98 to 100

32. Dextrocardia 101 & 102

5

1) ECG (Electro Cardio Gram) :

It is the Graphical record of Electrical Activity of Heart.

2) What are Leads?

- Potentials produced in heart are conducted all over body. These

potentials are picked by electrodes, amplified & recorded on paper.

Electrodes are called as leads.

3) Classification of Leads :

i) Bipolar or standard Leads-

Two leads are used positive & Negative electrodes.

Leads – I, II, III

ii) Unipolar Lead-

Only one electrode is used, other is earthed.

2 Types-

a)Unipolar chest Leads (V1 to V6)

b)Unipolar Limb leads (aVR aVL, aVF)

Important definitions

6

ECG – Graph Measurements

i) X axis - Indicates Duration or Time

Dot square = 0.04 sec

Big square = 0.2 sec

ii) Y Axis - Indicates Intensity of contraction

1 Dot square = 0.1 mV (milli volt)

1 Big square = 0.5 mV = 5 mm

2 Big squares = 1.0 mV = 10 mm

7

1) P wave - contraction of Atria

Amplitude = 0.2 mV (2dot squares)

Duration = 0.08 sec (2 dot squares)

(Note - In Atrial Hypertrophy P wave is either Tall or broad)

2) QRS Complex - Depolarization of both ventricles

Amplitude = 1.5 – 2.5 mV (3-5 large squares)

Duration = 0.08 sec (2 dot squares)

(Note - In ventricular Hypertrophy QRS complexes are tall)

3) T wave - Depolarization of ventricles.

Amplitude = 0.04 mV (4 dot squares)

Duration = 0.24 sec (6 dot squares)

(Note : In M. I. – T wave is flat or inverted.)

4) PR Interval - Indicates AV conduction time.

Normal = 0.12 to 0.16 sec (3-4 dot squares)

(Note - PR Interval is prolonged in AV Heart block)

Important measurements

8

Position of Chest leads

(Note - Space just below the sternal angel is

2nd Intercostal space.)

V1 = 4th Intercostal space, at Right sternal border.

V2 = 4th Intercostal space at Left sternal border.

V3 = In between V2 & V4.

V4 = 5th Intercostal space, at mid clavicular line.

V5 = Same horizontal level at V4

– Anterior axillary line (6th Intercostal space)

V6 = Same horizontal level at V4

– mid axillary line (7th Intercostal space)

9

Bipolar & Unipolar leads

10

Normal waves

ECG

11

12

13

14

15

H. R = 60 – 100 / min.

- P is upright in II & inverted in

AVR

- Every P wave is followed by

QRS complex.

Sinus Rhythm

16

Sinus Rhythm

- Normal cardiac Rhythm in which SA Node acts as

Natural Pacemaker, discharging 60 – 100 times / min.

- H.R. - 60 – 100 / min.

- P is upright in II & inverted in aVR

- Every P wave is followed by QRS complex.

17

Sinus Brady cardia

H.R < 60 / min

18

Sinus Bradycardia

- H. R. < 60/min.

- P is upright in II & inverted in aVR

- Every P wave is followed by QRS.

- Unusual - sinus Bradycardia < 40/min.

( Consider – Heart Block)

- Normal in athletes or during sleep.

- Other causes –

- Drugs - Digoxin, Beta blockers (Including Eye drops)

- IHD or M.I.

- Hypothyroidism.

- Hypothermia

- Electrolyte abnormalities.

- Obstructive Jaundice

- Uraemia

- Raised Intracranial pressure

- Sick sinus syndrome.

19

Sinus Tachycardia

H. R > 100 / min.

20

Sinus Tachycardia -H. R. > 100 / min.

-P upright in II & Inverted in aVR

-Every P wave is followed by QRS.

Rare, that sinus Tachycardia > 180 / min.

(Difficult to differentiate P wave from T waves –

Rhythm can be mistaken for AV nodal Re-entry Tachycardia.)

Physiological causes:

(Anything which stimulate sympathetic N. S. –

Anxiety, Pain, Fever, Exercise.)

Other causes

- Drugs - Adrenaline, Atropine, Salbutamol (Inhalers & Nebulizers),

Caffeins & Alcohol.

- IHD or Acute M. I.

- Heart failure

- Fluid Loss

- Anemia

- Hyperthyroidism.

21

If Appropriate Tachycardia -

• (Compensating for Low Bp e.g. Fluid Loss / Anemia) –

• with β blockers is Dangerous.

But,

•If sinus Tachycardia is

Inappropriate (Anxiety or Hyperthyroidism) –

with β blocker is O. K.

•Warning :

•In sinus Tachycardia

• - Never use β blocker to slow the Heart Rate unless -

you establish the cause.

22

Lt. Axis Deviation

a) Left Leaves

b) QRS +ve in I & -ve in III

23

Lt. Axis Deviation

a) Left Leaves.

b) QRS +ve in I & -ve in III.

Causes -

- Sometimes in Normal

- WPW syndrome

- Lt. anterior hemi block.

- Ventricular tachycardia

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In Right Axis Deviation

Right – Reaches

Nemonic

a) Lt Axis deviation -LVH, LBBB, Interior wall infarct.

b) Rt Axis deviation -RVH, RBBB, Anterior wall infarct.

I lead - R –ve

III lead - R +ve

25

Rt. Axis Deviation

a) Right Reaches

b) QRS is –ve in I & +ve in III

26

R.T Axis Deviation

a) Right Reaches

b) Observe only Lead I & III

c) QRS is –ve in I & +ve in III

Causes:

-May occur in Normal individual

-RVH

-Antero lateral M.I.

-Dextrocardia (Heart lies on Rt side of

chest)

-Lt. Posterior hemi block

-W.P.W Syndrome.

27

Ventricular Hypertrophy 1)Normal pattern & Amplitude of QRS complexes in chest ,

leads.

V1 = Small R wave & Deep S wave

V2

V3 When Proceeds towards

V4 V6 – Height of R wave increases & Depts.,

of s wave progressively decreases.

V5

V6

V1 V2 V3 V4 V5 V6

R

s

28

Pattern remains the same But Amplitude Increases.

If , SV1 > 25mm OR (5 Big squares).

RV6 > 25mm OR (5 Big squares).

SV1 + RV6 > 35 - LV (7 Big squares.)

Normal QRS complex = 3 to 5 large squares.

QRS - 1.5 – 2.5 mV - (3-5 large squares)

0.08 sec - (2dot squares)

LVH

V1 V2 V3 V4 V5 V6

R

s

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a) R in V5 or V6 >25mm

b) S in V1 or V2 >25 mm

c) R + S > 35 mm

LVH

30 a) R in V5 or V6 > 25mm b) S in V1 or V2 > 25mm

31

LVH

-R in V5 or V6 > 25 mm.

S in V1 or V2 > 25 mm.

-R V5/V6 + S V1 / V2 > 35 mm

This is not diagnostic

Young, thin people with Normal hearts have

R & S >Normal.

-If LVH - Look for evidence of strain

(ST depression & T Inversion)

-Eco-cardiography is Diagnostic for LVH.

- according to cause.

Causes :

- Hypertension

- Aortic stenosis

- Coaractation of Aorta

- Hypertrophic cardiomyopathy.

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RVH

Prominent R wave in V1 or Deep S wave in V6

SV1 to RV6 - Normal pattern.

OR

RV1 > 7 mm = 1 Big squares + 2 dot.

SV6 > 7 mm = 1 Big squares + 2 dot.

OR

RV1 + SV6 > 10 mm (2 big squares)

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a) Rt. Axis Deviation.

(RT. Reaches – I & III)

b) Deep S waves in V5 &

V6

c) RBBB (Broad QRS & M

in V1 & W in V6)

RVH

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RVH - Dominant R waves in V1 - V4

a) Rt Axis Deviation

b) Deep ‘S’ waves in V5 & V6

c) RBBB

- If strain - ST depression & T Inversion.

- Causes - Pulmonary Hypertension

Pulmonary stenosis

- - of underlying cause.

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P – Pulmonale

-Rt. Atrial Enlargement

- Tall P wave > 2.5 mm.

(2.5 dot squares) in II, III, avF

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Tall P wave > 2.5 mm.

(2.5 dot squares) in II, III, avF

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P Pulmonale Rt Atrial Enlargement

= Tall P wave > 2.5 mm (2.5 dot squares) in II, III, avF.

= Causes - RA – Enlargement

- Primary Pulmonary Hypertension.

- Secondary Pulmonary (Chr. Bronchitis, Emphysema)

- Pulmonary stenosis

- Tricuspid stenosis.

= patient’s H/O, Chest x-ray

(to assess cardiac dimensions & lung fields)

- Echo-cardiogram-to assess valvular disorders

- Estimate pulmonary artery pressure.

38

P – mitrale

-Lt. Atrial Enlargement

- P. wide > 0.08 sec or

(2 dot squares) & Bifid

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P. wide > 0.08 sec or (2 dot squares)

& Bifid

40

P-mitrale

Lt. Atrial Enlargement

= p wide > 0.08 sec, or

> 2 dot square

& Bifid

- Usually Result of mitral valve disease : called as P-mitrale.

-Lt. Atrial can also accompany LVH

(e.g. secondary to Hypertension, Aortic valve Disease

& Hypertrophic cardiomyopathy).

= - As like P pulmonale.

‘P mitrale’ – does not require treatment of its own.

41

Myocardial Infarction

3 cardinal signs on ECG in AMI -

1)Elevation of ST segment.

2)Inverted T wave.

3)Deep & wide Q wave.

42

Events in chronological Order

1)on 1st day - ST elevated

- with upright tall T wave

- but No Q wave

2)Over Next 2 day -

T wave will slowly become Inverted, ST seg still raised.

3)Towards the end of 1st wk -

- ST seg returning to base Level, T wave deeply inverted

- Q wave starts appearing.

- T wave - Pointed, Inverted & symmetrical Limbs.

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4)In 3rd week -

- Q wave fully developed.

- ST - Base

- T – wave flat & Returning to Normal.

5)By the end of 3 month -

-St seg & T wave – Return to Normal.

-Only Q wave remains permanent.

(of course if size of infarct is TOO small -Q wave may disappear)

-Q wave size is proportional to size of infarct.

44

Acute myocardial Ischemia

Angina = I cry

-Atherosclerotic Narrowing of coronary vessels.

-Pt. is comfortable at rest but anginal pain after exertion.

-After exercise, myocardium demand increases but sufficient

blood flow can not occur due to,

partially occluded coronary artery.

-Anginal pain disappears after Rest when demand decreases.

-Acute myocardial ischemia can be seen during stress test.

-Positive stress test - ST Depression.

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Types of ST seg Depression. 1) Horizontal or plain ST seg Depression.

This signifies myocardial ischemia.

2) Upward slopping ST seg Depression.

This is variant of Normal & significant only if,

point Depression > 2mm

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1)Horizontality of ST seg -

-ST seg – Horizontal & Isoelectric

-This is early manifestation of ischemia.

2)Downward slopping of ST seg -

This indicates severe Ischaemia

– Also seen in Digitalis toxicity.

47

1)Slaggy, concave upward ST seg-

Suggestive of Ischaemia.

2)Non Acute myocardial Ischaema-

Slight ST depression in V5, V6 & similar T inversion (Limb leads)

OR

Sometimes flattening of T wave in V5 & V6

(Just like strain pattern LVH)

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Anterior M.I.

= T Inversion in

V1 – V4

49

V1

V2

V3

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Anterior M.I.

- Q waves in Lead V4 – V4

- T Inversion in V1 – V4

ECG recorded, 5 days after Anterior M.I.

- Q waves, start to appear within few hrs of onset

& in 90% cases, becomes permanent.

- Of M.I. – chest pain, Nausea, Sweating.

51

Anterior M.I.

= S T Elevation in V1 – V4

52

V2 V3 V1

53

Inferior M.I

i) Q in II, III aVF

ii) T Inversion in II, III, aVF

54

i) Q in II, III aVF

ii) T Inversion in II, III, aVF

55

Inferior M.I.

1.Q in II, III, aVF

2.T Inversion in II, III & aVF

(2 yrs. previously attack.)

56

Inferior M. I

i) Q in II, III avF

ii) ST Elevation in II, III & avF

57 i) Q in II, III avF ii) ST Elevation in II, III & avF

58

Lateral M. I.

- S T Elevation in I, aVL, V4 – V6

- Hyper acute T waves in V4 & V5

59

i) S T Elevation in I, avL, V4 – V6

ii) Hyper acute T waves in V4 & V5

60

Lateral M. I.

-ST elevation in I, aVL, V4-V6.

-Hyper – acute T waves in Leads V4 & V5.

-R in V1-V3

-ST depression in V1-V3

-Upright Tall T waves in V2 & V3

61

Post. M. I

i) S T Depression in V1 – V3

62

S T Depression in V1 – V3

63

i) Anterior M. I. - V1 to V4

ii) Lateral M. I. - I, aVL, V5 – V6

iii) Antero Lateral - I, aVL,

V1 – V6.

iv) Antero-septal - V1 – V3

v) Interior M.I. - II, III, aVF

vi) Infero Lateral - I, II, III

aVL, aVF,

V5-V6.

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Exercise (stress) Test 1) ST Depression

2) Sometimes T Inversion

65

1) ST Depression

2) Sometimes T Inversion

66

Exercise Test

1. -Most common Indicator of coronary Artery Disease.

2. J point is the Junction of S wave & ST segment.

3. Measure ST Depression, 2 dot square after J point.

4. T Inversion, may develop during exercise (as may BBB)

5. A fall in systolic pressure indicates sever coronary Disease

6. Greater the Depression - Higher probability of coronary

Heart Disease.

-1st degree Heart Block.

-Long PR interval.

(Normal-PR)

= 0.12-0.20 sec.

= 3-5 dot squares.

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(Normal-PR)

= 0.12-0.20 sec.

= 3-5 dot squares

69

1st Degree Heart block

Long PR Interval

0.12 - 0.2 sec

3 small sq. - 5 small sq.

Causes -IHD

-Hypokalaemia

(Low potassium, due to Diver tics)

-Acute Rheumatic myocarditis,

-Drugs (Digoxin ,B blockers,

Ca+ channel blocks)

= Asymptomatic.

= No specific Rx

= Not Indication for a pacemaker.

70

Mobitz Type1-AV Block

=Progressive lengthening

of PR interval.

=Then P wave-fails to be

conducted.

=PR interval Resets &

cycle repeats.

71

72

Mobitz Type I - AV Block

One of the types of 2nd degree

Heart block – Also known as “Wenckebach

phenomenon”.

a) Progressive Lengthening of PR Interval

b) Then p wave – fails to be conducted

c) PR Interval resets 7 cycle repeats

= Abnormal conducting, through AV node

(during High vagal activity – some times

during sleep.)

= In Generalized disease of conducting

tissues.

= Benign form of AV block .

(permanent pace maker not required)

– Temporary pacing before surgery.

73

Mobitz Type 2-AV Block

=PR Normal & constant.

=Occasional P wave-fails

to be conducted.

75

Mobitz Type II - AV Block

a) PR - Normal & Constant

b)Occasional P wave – fails to be conducted.

= Result from abnormal conduction,

below AV node (in Bundle of His)

= More serious than type I

= Refer to cardiologist: Pacemaker may be

needed

= Indications for pacing – Acute M.I or

pre-operatively.

76

3rd degrees Heart Block a) P wave (atrial) Rate = 85 / min

b) QRS complex (ventricular) rate = 54 / min

c) Broad QRS complexes

d) No Relation between – P waves & QRS complexes

Third-degree AV block

77

78

3rd degree Heart Block

Complete Heart Block

Complete Interruption of conduction between,

Atria & ventricles & two are working Independently.

- In Acute inferior M.I. - 3rd deg. AV Block – Pacing.

- Acute Anterior wall M.I – 3rd degree heart Block.

Indicates extensive infarct & poor prognosis.

- Temporary pacing – pri-operatively

- If due to 3rd degree Block

Heart failure, Dizziness, fall, loss of

consciousness-Permanent pacing is indicated.

a) P wave (atrial) rate = 85 / min.

b) QRS complex (ventricular) rate = 54 / min.

c) Broad QRS complexes.

d) No Relation between – P waves & QRS complexes

79

2 : 1 AV Block a) Alternate P waves fail to be conducted

(Alternate P waves are not followed by QRS

complexes)

b) AV block is a special form of 2nd degree Heart

block

2:1 AV

block

80

Non-conducted P

Wave

conducted P

Wave

81

2: 1 AV Block

- Alternate P waves fail to be conducted .

(Alternate P waves are not followed by

QRS complexes)

- AV block is a special form of 2nd degree

Heart Block.

82

LBBB

a) Broad QRS complexes.

Normal – QRS < 0.12 sec

QRS < 3 small

square

b) QRS looks like W in V1 &

M in V6 (william).

83

QRS looks like W in V1

& M in V6 (william).

Q

84

B.B.B

LBBB

a) Broad QRS complexes

b) QRS morphology – as explained in Text.

Normal: QRS < 0.12 sec

QRS < 3.5 small squares

QRS looks like W in V1 & M in V6 (William)

Causes-

- IHD

- LVH (Hypertension, aortic stenosis),

- Fibrosis of conduction system.

Asymptomatic & do not required of their own

right.

85

RBBB

a) Broad QRS complexes.

b) QRS looks like M in V1 &

W in V6

(M orro w)

86

QRS looks like M in

V1 & W in V6

(M orro w)

87

a)Broad QRS complexes

b)QRS morphology as explained in Text.

Normal QRS < 0.12 sec.

QRS < 3 dot squares.

QRS Looks like ‘M’ in Lead V1 & ‘w’ in lead V6 (morrow).

Causes -

- IHD,

- Cardiomyopathy,

- Atrial septal defects,

- Massive pulmonary embolism.

-RBBB is relatively common finding in otherwise normal

hearts.

-Both LBBB & RBBB are asymptomatic in themselves

& do not require treatment in their own right.

RBBB

88

Hyper Ca ++

Normal QTC

= 0.35 – 0.43 sec

Short QT

89

causes of hypercalcaemia -

- Hyperparathyroidism. (Primary or Tertiary)

- Malignancy (Myeloma)

- Drugs (Thiazide Diuretics, excessive vit D intake.

- Sarcoidosis

- Thyrotoxicosis.

= Risk of cardiac arrest

with Severe Hypercalcaemia.

= Severe symptoms :

- vomiting, Drowsiness & plasma Ca+ > 3.5 mmol / L -

Urgent Rx

- I / V - 0.9 % saline (3 to 4 lit / 24 hrs)

- I / V Frusemide (20-40 mg/ every 6 – 12 hrs)

- Disodium pamidronate – single Infusion.

Monitor Urea & Electrolytes ca+ level – Every 12 hrs

90

Hyper Ca+

- To calculate QT Interval is not straight forward:

Duration varies with H. R.

Faster H. R. - Shorter QT

QTC = QT

RR

Normal QTC = 0.35 - 0.43 sec.

= Fig. - QT = 0.26 sec.

HR = 100 / min.

QTC = 0.34 sec.

= Sym of Hypercalcaemia.

Anorexia, wt. Loss, Nausea, Vomiting, abdominal pain,

constipation, polydypsia, polyuria, weakness & depression.

= Prominent U wave

= Confirm by Plasma ca+ Level.

91

Hypocalcaemia

- Long QT Interval

92

Hypocalcaemia

-Long QT Interval (0.57 s)

-H. R = 51 / min.

-Q TC = 0.52 sec.

= C/F - Peripheral & circumoral paraesthesiae, Tetany,

Fits & Psychiatric Disturbance.

- Trousseaus sign :

(carpal spasm, when Brachial Artery is occluded with

BP cuff)

- Chovosteks sign :

Twitching of facial muscles, when tapping over facial

Nerve.

- Papilloedema

93

-Confirm -

- By plasma Ca+ level

-(Not forgetting to check simultaneous Alb. level)

Causes –

- Hypoparathyroidism.

(Following Thyroid surgery, Auto immune or Congenital)

- Chr. Renal failure

- Vit. D Deficiency

- Drugs like calcitonin

- Acute pancreatitis

= Inj. Ca- Gluconate 10% - 10ml.

94

Hyperkalaemia

= Tall Tented T waves

95

Hyperkalaemia

= Tall ‘Tented’ T wave

Hyperkalaemia also cause:

-Flattening & even loss of P wave.

-Lengthening of PR

-Widening of QRS complex.

-Arrhythmias.

- Confirmed by - Elevated plasma potassium level.

-Underlying cause - Renal Failure.

-Complete Drug H/O is Essential in any pt. with abnormal ECG.

96

Hypokalaemia

-Small T wave &

-Prominent U wave

-Changes, which may accompany Hypokalaemia:

- First degree Heart Block

- Depression of ST segment

- Prominent U wave.

= C/F - muscle weakness & cramps.

= Commonest cause for hypokalaemia is Diuretics.

97

Hypokalaemia

- Small T wave & Prominent U wave

98

= Reverse Tick (ST depression)

Digoxin Effect

99

Reverse Tick (ST depression)

100

Digoxin Effect

= “Reverse Tick” - ST depression

- Reduction of T wave size shortening of QT

At. Toxic level-

-T Inversion

-Arrhythmias, Sinus Bradycardia ,Ventricular

Tachycardia

= Reverse Tick.

101

- P wave Inverted in I &

Rt. Axis Deviation

- Decrease in R wave height,

across chest leads.

Heart Lies on Rt. side

102

Heart lies on Rt. side

-Decrease in R wave height across chest leads.

-Heart lies on RT side.

-P wave Inverted in I & Rt Axis Deviation.

-For - Location of Apex beat, do the chest x-ray

Kartagener’s syndrome:

-Dextrocardia + Bronachiectasis + sinusitis.

-No. specific .

103

1. Introduction 5 to 10

2. Electric circuit of heart 11

3. Waves of ECG 12

4. Normal ECG of chest leads 13

5. ECG of I,II,III,aVR,aVL,aVF leads 14

6. Sinus Rhythm 15 & 16

7. Sinus Bradycardia 17 & 18

8. Sinus Tachycardia 19 to 21

9. Left Axis Deviation 22 & 23

10. Right Axis Deviation 24 to 26

104

11. Normal pattern of QRS complex 27

12. LVH 28 to 31

13. RVH 32 to 34

14. RAH 35 to 37

15. LAH 38 to 40

16. M.I 41 to 43

17. Angina 44 to 47

18. M.I 48 to 63

19. Stress Test 64 to 66

20. 1st Degree Heart block 67 to 69

21. Mobitz type 1 AV block 70 to 72

22. Mobitz type 2 AV block 73 to 75

105

23. 3rd Degree Heart block 76 to 78

24. 2:1 AV Block 79 to 81

25. LBBB 82 to 84

26. RBBB 85 to 87

27. Hyper Ca++ 88 to 90

28. Hypo Ca++ 91 to 93

29. Hyper Kalaemia 94 & 95

30. Hypo Kalaemia 96 & 97

31. Digoxin effect 98 to 100

32. Dextrocardia 101 & 102

106