This document provides an overview of ECG samples and diagnosis for medical students. It discusses the basics of ECG interpretation, normal sinus rhythm, intervals, waveforms, abnormalities, myocardial infarction, bundle branch blocks, ventricular hypertrophy, atrial fibrillation, and more. Examples of various abnormal ECG patterns are presented along with explanations. Sources include textbooks and online resources for ECG learning. The document is intended for educational presentation purposes.

1. ECG SAMPLES AND DIAGNOSIS FOR MBBS
NABYENDU BISWAS
COMMUNITY MEMBER EXECUTIVE, ELSEVIER
drnabyendu365@gmail.com
ECG MADE EASY

2. SOURCES AND PREDICTIONS
FIRST OF ALL EVERYTHING IN THIS DOCUMENT WRITTEN IN CAPITALS, SO aVF WRITTEN AS AVF IN EVERY
PORTION OF THIS DOCUMENT WHICH IS NOT COREECT.
SECONDLY IN EVERY ECG IT IS NOT POSSIBLE TO EXPLAN EACH AND EVERY FINDINGS AVAILABLE. SO, I DISCUSS
ABOUT THE MAJOR FINDINGS ONLY.
DUE TO LACK OF SPACE I AM NOT ABLE TO DISCUSS THE BASIC PHYSIOLOGY OF HEART IN THIS DOCUMENT.
THIS DOCUMENT IS ONLY FOR PRESENTATION PURPOSE SO, COPYRIGHT PROTECTION IS NOT MAINTAINED.
SOURCES-
DIAGNOSIS IN COLOUR CARDIOLOGY BY TIMMIS AND BRECKER.
DAVIDSON’S PRINCIPLES AND PRACTICE OF MEDICINE
ECG LEARNING CENTRE ecg.utah.edu
ECGpedia
NCBI
ECG COLLECTED FROM RURAL HOSPITALS, WEST BENGAL
ECG MADE EASY

3. BASIC OF ECG
ECG MADE EASY

4. NORMAL INTERVAL
ECG MADE EASY

5. BASIC OF ECG INTERPRETATION
ECG MADE EASY

6. NORMAL SINUS RHYTHM
ECG MADE EASY

7. NORMAL ECG INTERVALS AND
PARAMETERS
ECG MADE EASY

8. EASY TO REMEMBER
ECG MADE EASY

9. HOW TO CALCULATE HEART RATE
ECG MADE EASY

10. AREAS INVOLVED SHORCUT
ECG MADE EASY

11. WAVE FORM DISCUSSIONS
ECG MADE EASY

12. NORMAL P WAVES AND ABNORMALITIES
GENERALLY TALL P WAVES IN
LEAD II MAINLY SIGNIFIES
PULMONARY HYPERTENSION
AND HYPERTROPHY.
ECG MADE EASY
ECG MADE EASY

13. QRS COMPLEX DETAILS
R WAVE CANNOT BE NEGATIVE
AND
Q WAVE CANNOT BE POSITIVE
ECG MADE EASY

14. IN DOUBTFUL SITUATION
ECG MADE EASY

15. ECG MADE EASY

16. R WAVE
CANNOT
BE
NEGATIVE
AND
Q WAVE
CANNOT
BE
POSITIVE
ECG MADE EASY

17. ST COMPLEX DETAILS
ECG MADE EASY

18. CAUSES OF TALL PEAK T WAVES
ECG MADE EASY

19. IN DOUBTFUL SITUATION
ECG MADE EASY

20. T WAVE INVERSION DETAILS
ECG MADE EASY

21. MORPHOLOGY OF R AND S WAVE CHANGES IN V LEADS
ECG MADE EASY

22. ABNORMAL ECG GRAPHS AND EXPLANATION
ECG MADE EASY

23. CAUSES OF IRREGULAR PULSE
ECG MADE EASY

24. BUNDLE BRANCH BLOCK
LEFT BUNDLE
BRANCH BLOCK
1. M PATTERN IN LEAD I
2. W PATTERN IN V4
3. QRS COMPLEX >= 120
ms
ECG MADE EASY

25. LEFT BUNDLE BRANCH BLOCK WITH MI
LEFT BUNDLE
BRANCH BLOCK
1. M PATTERN IN LEAD I
2. W PATTERN IN V1
3. QRS COMPLEX >= 120
ms
ECG MADE EASY

26. LBBB is recognized by 1) QRS duration
>0.12s; 2) monophasic R waves in I and
V6; and 3) terminal QRS forces
oriented leftwards and posterior.
The ST-T waves should be oriented
opposite to the terminal QRS forces.
DIFFERENCE BETWEEN
NORMAL AND
MONOPHASIC R
WAVE
ECG MADE EASY

27. RIGHT BUNDLE
BRANCH BLOCK
RABBIT EAR PATTERN
ECG MADE EASY

28. BUNDLE BRANCH BLOCK
RIGHT BUNDLE
BRANCH BLOCK
RABBIT EAR PATTERN
ECG MADE EASY

29. ECG MADE EASY

30. r
S
R’
DOUBT
r
S
R’
R WAVE CANNOT BE NEGATIVE
AND
Q WAVE CANNOT BE POSITIVE
ECG MADE EASY

31. RBBB is recognized by 1) rR' in V1; 2) QRS duration >0.12s. In RBBB the ST-T waves should be
oriented opposite to the terminal QRS forces. In this example there are "primary ST-T wave
abnormalities" in leads I, II, aVL, V5, V6. In these leads the ST-T orientation is in the same direction
as the terminal QRS forces.
ECG MADE EASY

32. DIFFERENCE BETWEEN RBBB AND LBBB
ECG MADE EASY

33. ECG MADE EASY

34. VENTRICULAR HYPERTROPHY
ECG MADE EASY

35. LEFT VENTRICULAR
HYPERTROPHY
1. STANDARDIZATION
AT HALF VOLTAGE
2. LARGE ST-T IN
V5,V6
3. QRS COMPLEX
MAY BE SLIGHTLY
WIDENED IN LIMB
LEADS (LEADI, II
AND III)
4. T INVERSION IN
V5, V6
ECG MADE EASY

36. ECG MADE EASY

37. ECG MADE EASY

38. ECG MADE EASY

39. ECG MADE EASY

40. ECG MADE EASY

41. ECG MADE
EASYVV

42. ECG MADE EASY

43. ECG MADE EASY

44. ECG MADE EASY

45. ECG MADE EASY

46. ECG MADE EASY

47. ECG MADE EASY

48. ATRIAL FIBRILLATION IN DETAILS
ECG MADE EASY

49. ATRIAL FIBRILLATION ECG
1. THE VENTRICULAR COMPLEXES ARE IRREGULAR
2. THERE ARE NO P WAVES AND IRREGULAR OSCILLATIONS DISTUREB THE
BASELINE.
ECG MADE EASY

50. PAROXYSMAL VENTRICULAR
TACHYCARDIA
ECG MADE EASY

51. WPW SYNDROME UNLOCKED
ECG MADE EASY

52. ECG MADE EASY

53. ABNORMAL
ECG
ECG MADE EASY

54. ECG MADE EASY

55. IRREGULAR PULSE ECG
VENTRICULAR
COMPLEX AFTER T
WAVE.
CHANGE IN P WAVE
PATTERN IN RED
BOUND AREA.
SINUS PAUSE
VISIBLE.
ECG MADE EASY

56. ECG MADE EASY

58. TYPES OF AV BLOCKS
1. IN 1ST DEGREE HEART
BLOCK AV CONDUCTION
IS DELAYED RESULTING IN
PROLONGED PR INTERVAL
i.e. 0.20 sec.
2. ST ELEVATION MAY BE
FOUND.
DROPPED
BEAT
ECG MADE EASY

59. HEART BLOCK DISCUSSION
DOUBT
1. IN 1ST DEGREE HEART BLOCK AV
CONDUCTION IS DELAYED RESULTING
IN PROLONGED PR INTERVAL i.e. 0.20
sec.
2. IN 2ND DEGREE HEART BLOCK
(PARTIAL HEART BLOCK) SOME
IMPULSES FROM THE ATRIA FAILED TO
GET THROUGHTO THE VENTRICLES i.e.
DROPPED BEAT OCCURS.
SOMETIMES THERE IS
PROGRESSIVE LENGTHENING OF
SUCCESSIVE PR INTERVALS FOLLOWED
BY A DROPPED BEAT
ECG MADE EASY

60. EXERCISE ECG CHANGES
ISCHAEMIC CHANGES ARE
VISIBLE. AFTER 3 MINUTES
PLANER ST DEPRESSION
DEVOLOPED AND AT 6
MINS IT IS MORE
PRONOUNCED.
PROBABLE DIAGNOSIS-
CORONARY ARTERY
DISEASE
ECG MADE EASY

61. ECG MADE EASY

62. EXERCISE ECG CHANGES
J POINT DEPRESSION
ST DEPRESSION PROVOKED BY EXERCISE
ECG MADE EASY

63. QQQQQQQQQQQQQQQQQQQQQQQQQQQQ
QQQQQQQQQQQQQQQQQQQQQQQQQQQQ
QQQQQQQQQQQQQQQQQQQQQQQQQQQQ
QQQQQQQQQQQQQQQQQQQQQQQQQQ
PATIENT WITH UNSTABLE ANGINA SHOWS PROFOUND ST SEGMENT
DEPRESSION EXTENDING FROM V3 TO V6
ST DEPRESSION GENERALLY INDICATES URGENT CARDIAC
CATHETERIZATION. UNSTABLE
ANGINA
ECG MADE EASY

64. VARIANT
ANGINA
VARIANT ANGINA, ECG SHOWS
PROFOUND ST ELEVATIONS IN V1- V4
ECG MADE EASY

65. ACUTE MYOCARDIAL INFARCTION
ECG MADE EASY

66. ACUTE
ANTERIOR
INFARCTION
ACUTE
INFERIOR
INFARCTION
ECG MADE EASY

67. ACUTE
INFERIOR
INFARCTION
IN DETAILS
ECG MADE EASY

68. ACUTE
INFERIOR
INFARCTION
IN DETAILS
ECG MADE EASY

69. ACUTE
LATERAL
INFARCTION
ACUTE
POSTERIOR
INFARCTION
ECG MADE EASY

70. ACUTE
ANTERIOR
INFARCTION
ECG MADE EASY

71. CLASSICAL T WAVE
INVERSION.
BUT SINCE ST ELEVATION
OR DEPRESSION NOT
PROMINENT SO DIAGNOSIS
CANNOT BE CONFIRMED.
ECG
MADE
EASY

72. PATHOLOGICAL Q WAVES AND EVOLVING ST SEGMENT ELEVATION SIGNIFIES
STEMI, NOTE ST ELEVATION IN LEAD II, III, AVF
ST SEGMENT DEPRESSION ALSO PRESENT IN V1-3 REPRESENTS TRUE
POSTERIOR INJURY
ACUTE INFERIOR WALL MI
ECG MADE EASY

73. PATHOLOGICAL Q WAVE IS MOST
SIGNIFICANT IN THIS ECG
LARGEST Q IN III, NXT IN AVF AND
SMALLEST IN II
OLD INFERIOR Q WAVE MI
DOUBT
Q. WHERE IS THE Q IN LEAD III
ANS. LOOK CAREFULLY AT LEAD III, THERE IS P WAVE
POSITIVE AND WAVE FOLLOWED BY P WAVE
SHOLULD BE POSITIVE, SINCE IT IS NEGATIVE AND
NOT FOLLOWED Y A POSITIVE WAVE SO IT ISNOT
S, IT MUT BE Q
ECG MADE EASY

74. 15 LEAD ECG SHOWING ST ELEVATION IN V8-9 AND ST DEPRESSION IN V1-6
AND FINALLY SLIGHT ST ELEVATION IN I, AVL.
ST DEPRESSION IN V4R SIGNIFIES LEFT CIRCUMFLEX OCCLUSION.
ACUTE POSTERIOR MI DUE TO LEFT CIRCUMFLEX OCCLUSION ECG MADE EASY

75. TALL R WAVES IN V1-3
DEEP Q WAVE IN LEAD II, III, AVF
RESIDUAL ST-T ABNORMALITIES ALSO PRESENT
OLD INFEROPOSTERIOR MI
DOUBT
THE MAIN POINT BY WHICH WE
DIFFERENTIATE ACUTE AND OLD MI IS THAT
ACUTE MI= ST SEGMENT ELEVATION
OLD MI= ST ELEVATION + PATHOLOGICAL Q
ECG MADE EASY

76. SIGNIFICANT ST ELEVATION
ACUTE INFERIOR STEMI FINDINGS IN LEAD II, III, AVF (ST ELEVATION IN II, III
AND ST DEPRESSION IN LEAD I)
AND ST ELEVATION IN V3R TO V6R ;INDICATIVE OF RIGHT VENTRICULAR
INJURY
RIGHT VENTRICULAR MI
ECG MADE EASY

77. Acute anterior or anterolateral MI (note Q's V2-6 plus hyper acute ST-T changes)
ANTERIOR MI SINCE PROMINENT CHANGES FOUND IN V2, V3
Q WAVE
ECG MADE EASY

78. Q-wave, slight ST elevation, and T inversion in lead AVL
LATERAL MI
TYPICAL MI FEATURES IN LEADI/ AVL
ECG MADE EASY

79. The QS complexes, resolving ST
segment elevation and T wave
inversions in V1-2 are evidence for a
fully evolved anteroseptal MI. The
inverted T waves in V3-5, I, aVL are
also probably related to the MI.
ANTEROSEPTAL MI
DOUBT
Q. IS IT REALLY T INVERSION IN V2
ANS. FOR THIS JUST CHECK THERE IS A SMALL POSITIVE P WAVE, SO
AS WE KNOW AVR IS A REVERSAL OR NEGATIVE LEAD AND THERE
EACH AND EVERY WAVE FORM GIVES OPPOSITE VALUE BUT HERE P
IS IN RIGHT DIRECTION MEANS UPWARDS. SO, T SHOULD BE
UPWARDS SINCE IT IS A POSITIVE WAVE LIKE P
BUT IT IS INVERTED.
P
ECG MADE EASY

80. Hyperacute T waves in inferior wall STEMI
DOUBT
WHY INFERIOR WALL STEMI
IN LEAD II MARKED ST ELEVATION FOUND
IN LEAD III ALSO MARKED ST ELEVATION
FOUND
IN AVF ALSO MARKED ST ELEVATION
FOUND
ECG MADE EASY

81. The ST segments are elevated in Leads II, III,
and aVF, but the amount of elevation may
look subtle to some.
INFERIOR WALL MI
This ECG shows a common
manifestation with inferior wall
M.I., BRADYCARDIA. We see
the signs of acute inferior wall
M.I.
ECG MADE EASY

82. ECG MADE EASY

83. QQQQQQQQQQQQQQQQQQQQ
ST segment depression is a nonspecific
abnormality that must be evaluated in the
clinical context in which it occurs. In a patient
with angina pectoris ST depression usually
means subendocardial ischemia.
ECG MADE EASY

84. POINTS TO REMEMBER
ST ELEVATION SIGNIFIES
 ACUTE MYOCARDIAL INFARCTION
 CORONARY VASOSPASM (PRINTZMETAL
ANGINA)
 PERICARDITIS
 LEFT BUNDLE BRANCH BLOCK
 LEFT VENTRICULAR HYPERTROPHY
ST DEPRESSION SIGNIFIES
 MYOCARDIAL ISCHAEMIA
 SUBENDOCARDIAL ISCHAEMIA
 NON Q WAVE MYOCARDIAL
INFAQRCTION
 ASSOCIATED WITH T WAVE CHANGES IN
UNSTABLE ANGINA
PATHOLOGICAL Q SIGNIFIES
 PREVIOUS MYOCARDIAL INFARCTION
OR OLD INFARCTION
 LEAD III OFTEN SHOWS Q WAVES, WHICH
ARE NOT PATHOLOGICAL AS LONG AS Q
WAVES ARE ABSENT IN LEAD II AND AVF
T WAVE MORPHOLOGY
 UPRIGHT IN ALL LEADS EXCEPT AVR, V1
 AMPLITUDE < 5MM IN LIMB LEADS, < 15MM IN PRECORDIAL
LEADS
 PEAK T WAVES FOUND IN HYPERKALEMIA
 BROAD, ASYMMETRICALLY PEAKED OR HYPERACUTE T WAVES
ARE SEEN IN THE EARLY STAGE OF ST ELEVATION MI( STEMI)
 T WAVE INVERSION PRESENT IN MYOCARDIAL ISCHAEMIA,
BUNDLE BRANCH BLOCK MAINLY AND IT IS A NORMAL FINDING
IN CHILREN.
 IN MI INFERIOR- II,III,AVF
 LATERAL- I, AVL, V5-6
 ANTERIOR- V2-6
P WAVE SIGNIFIES
 IT REPRESENTS ATRIAL DEPOLARISATION
 MONOPHSIC IN LEAD II
 BIPHASIC IN V1
 IN RIGHT ATRIAL ENLARGEMENT LEAD II GIVES TALL
P WAVE ALTHOUGH THE WIDTH REMAINS
UNCHANGED
 IN LEFT ATRIUM ENLARGEMENT THE WIDTH
INCREASES BUT THE HEIGHT OF P WAVE REMAINS
CONSTANT.
 IN PULMONARY HYPERTENSION AND HYPERTROPHY
GENERALLY TALL P WAVE FOUND.
RT ATRIUM
LT ATRIUM
NORMAL P WAVE TALL P WAVE
RT ATRIUM ENLARGEMENT
WIDE P WAVE
LT ATRIUM ENLARGEMENT
ECG MADE EASY

85. ECG MADE EASY

86.  P-R SEGMENT- 2-3 SMALL SQUARES
 P-R INTERVAL – 4-5 SMALL SQUARES
 QRS COMPLEX SHOULD BE < 3 SMALL SQUARES
UPRIGHT IN LEAD I, II
 QRS AND T WAVES HAVE THE SAME CONFIGURATION IN LIMB LEADS(I, II, III,
AVL, AVR, AVF)
 ALL WAVES ARE NEGATIVE IN AVR
 IN V LEADS R WAVE SHOLUD GROW FROM V1-V2Q AND REACHES
MAXIMUM IN V3
 IN S WAVE- IT WILL ALSO GROW FROM V1-V3 BUT IN V5-V6 IT WILL BE
ABSENT
 ST SEGMENT SHOULD BE ISOELECTRIC EXCEPT V1, V2
 P WAVE SHOULD BE UPRIGHT IN I, II, AVF, V2- V6
 T WAVE SHOULD BE UPRIGHT IN I, II, AVF, V2 TO V6
 Q WAVE MAY BE ABSENT IN II, III, V2-V6 LESS THAN 0.04 SECOND
 AXIS DETERMINATION
NORMAL
LEFT AXIS
DEVIATION
RIGHT AXIS
DEVIATION
INDETERMINATE
THUMB RULE
LEFT THUMB- LEAD I
RIGHT THUMB- AVF
LEAD I AVF
+ - + -
INTERPRETATION
2 THUMBS UP- BOTH +
LEAD I UP 0+, AVF DOWN - LEFT AXIS DEVIATION
LEAD I DOWN -, AVF UP + RIGHT AXIS DEVIATION
RULES
FOR
EASY
DIAGNOSIS
ECG MADE EASY

87. XRAY DIAGNOSIS MADE EASY CT SCAN DIAGNOSIS MADE EASY
COMING SOON
ECG MADE EASY