This document provides an overview of key topics in electrocardiography (ECG). It begins with definitions of an ECG and electrode leads. It then covers normal ECG wave patterns and measurements. Various abnormal ECG patterns are discussed including sinus bradycardia/tachycardia, ventricular hypertrophy, myocardial infarction in different regions, and more. Diagrams are provided to illustrate normal and abnormal ECG findings. The document serves as a guide to interpreting ECGs and recognizing common cardiac conditions.
2. TITLE
1. Introduction
Slide Number
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
2
3. 11. Normal pattern of QRS complex
12. LVH
13. RVH
14. RAH
15. LAH
16. M.I
17. Angina
18. M.I
19. Stress Test
20. 1st Degree Heart block
21. Mobitz type 1 AV block
22. Mobitz type 2 AV block
27
28 to 31
32 to 34
35 to 37
38 to 40
41 to 43
44 to 47
48 to 63
64 to 66
67 to 69
70 to 72
73 to 75
3
4. 23. 3rd Degree Heart block
24. 2:1 AV Block
25. LBBB
26. RBBB
27. Hyper Ca++
28. Hypo Ca++
29. Hyper Kalaemia
30. Hypo Kalaemia
31. Digoxin effect
32. Dextrocardia
76 to 78
79 to 81
82 to 84
85 to 87
88 to 90
91 to 93
94 & 95
96 & 97
98 to 100
101 & 102
4
5. Important definitions
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 LeadsTwo leads are used positive & Negative electrodes.
Leads – I, II, III
ii) Unipolar LeadOnly one electrode is used, other is earthed.
2 Typesa)Unipolar chest Leads (V1 to V6)
b)Unipolar Limb leads (aVR aVL, aVF)
5
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
6
7. 1)
Important measurements
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)
7
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)
8
15. Sinus Rhythm
H. R = 60 – 100 / min.
- P is upright in II & inverted in
AVR
- Every P wave is followed by
QRS complex.
15
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.
16
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
18
Sick sinus syndrome.
-
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.
20
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.
21
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
23
24. In Right Axis Deviation
I lead - R –ve
III lead - R +ve
Right – Reaches
Nemonic
a) Lt Axis deviation -LVH, LBBB, Interior wall infarct.
b) Rt Axis deviation -RVH, RBBB, Anterior wall infarct.
24
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.
26
27. Ventricular Hypertrophy
1)Normal pattern & Amplitude of QRS complexes in chest ,
leads.
V1
=
V2
V3
V4
V5
V6
Small R wave & Deep S wave
When Proceeds towards
V6 – Height of R wave increases & Depts.,
of s wave progressively decreases.
R
27
V1
V2
V3
V4
V5
V6
s
28. LVH
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
0.08 sec
-
(3-5 large squares)
(2dot squares)
R
28
V1
V2
V3
V4
V5
V6
s
29. LVH
a) R in V5 or V6 >25mm
b) S in V1 or V2 >25 mm
c) R + S > 35 mm
29
30. a) R in V5 or V6 > 25mm
b) S in V1 or V2 > 25mm30
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.
31
32. RVH
Prominent R wave in V1 or Deep S wave in V6
SV1 to RV6 - Normal pattern.
OR
RV1 > 7 mm
SV6 > 7 mm
= 1 Big squares + 2 dot.
= 1 Big squares + 2 dot.
OR
RV1 + SV6 > 10 mm (2 big squares)
32
34. 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.
-
34
35. P – Pulmonale
-Rt. Atrial Enlargement
- Tall P wave > 2.5 mm.
(2.5 dot squares) in II, III, avF
35
36. Tall P wave > 2.5 mm.
(2.5 dot squares) in II, III, avF
36
37. 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.
37
38. P – mitrale
-Lt. Atrial Enlargement
- P. wide > 0.08 sec or
(2 dot squares) & Bifid
38
39. P. wide > 0.08 sec or (2 dot squares)
& Bifid
39
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.
40
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.
42
43. 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.
43
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.
44
45. 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
45
46. 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
46
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
47
(Just like strain pattern LVH)
50. 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.
50
54. i) Q in II, III aVF
ii) T Inversion in II, III, aVF
54
55. Inferior M.I.
1. Q in II, III, aVF
2.T Inversion in II, III & aVF
(2 yrs. previously attack.)
55
56. Inferior M. I
i) Q in II, III avF
ii) ST Elevation in II, III & avF
56
57. i) Q in II, III avF
ii) ST Elevation in II, III & avF 57
58. Lateral M. I.
- S T Elevation in I, aVL, V4 – V6
- Hyper acute T waves in V4 & V5
58
59. i) S T Elevation in I, avL, V4 – V6
ii) Hyper acute T waves in V4 & V5
59
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
60
63. i) Anterior M. I.
ii) Lateral M. I.
-
V1 to V4
-
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.
63
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.
66
72. Mobitz Type I - AV Block
One of the types of 2nd degree
Heart block – Also known as “Wenckebach
phenomenon”.
a)
b)
c)
Progressive Lengthening of PR Interval
Then p wave – fails to be conducted
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.
72
73. Mobitz Type 2-AV Block
=PR Normal & constant.
=Occasional P wave-fails
to be conducted.
73
74. 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.
75
75. Third-degree AV block
3rd degrees Heart Block
a)
b)
c)
d)
P wave (atrial) Rate = 85 / min
QRS complex (ventricular) rate = 54 / min
Broad QRS complexes
No Relation between – P waves & QRS complexes
76
77. 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
78
78. 2:1 AV
block
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
79
80. 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.
81
81. 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).
82
83. B.B.B
LBBB
a)
b)
Broad QRS complexes
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
right.
of their own
84
84. RBBB
a) Broad QRS complexes.
b) QRS looks like M in V1 &
W in V6
(M orro w)
85
86. RBBB
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.
87
88. 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
89
89. 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.
90
94. 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.
95
95. 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.
96
99. 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.
100
100. Heart Lies on Rt. side
- P wave Inverted in I &
Rt. Axis Deviation
- Decrease in R wave height,
across chest leads.
101
101. 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
.
102
102. 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
103
103. 11. Normal pattern of QRS complex
12. LVH
13. RVH
14. RAH
15. LAH
16. M.I
17. Angina
18. M.I
19. Stress Test
20. 1st Degree Heart block
21. Mobitz type 1 AV block
22. Mobitz type 2 AV block
27
28 to 31
32 to 34
35 to 37
38 to 40
41 to 43
44 to 47
48 to 63
64 to 66
67 to 69
70 to 72
73 to 75
104
104. 23. 3rd Degree Heart block
24. 2:1 AV Block
25. LBBB
26. RBBB
27. Hyper Ca++
28. Hypo Ca++
29. Hyper Kalaemia
30. Hypo Kalaemia
31. Digoxin effect
32. Dextrocardia
76 to 78
79 to 81
82 to 84
85 to 87
88 to 90
91 to 93
94 & 95
96 & 97
98 to 100
101 & 102
105