For starters

1. Basics of ECG & Chamber
Enlargement
“The Life is all about ups &
downs”
Dr.Ashish Behera
Asst.Professor
Department of
Medicine

2. • 1895 - William Einthoven , credited for the invention of EKG
• 1924 - the noble prize for physiology or medicine is given to
William Einthoven for his work on EKG
• 1938 -AHA and Cardiac society of great Britan defined and
position of chest leads.
• 1942- Goldberger increased Wilson’s Unipolar lead voltage by
50% and made Augmented lead.
• 2005- successful reduction in time of onset of chest pain and
PTCA by wireless transmission of ECG on his PDA.

4. • ‘ECG’ stands for electrocardiogram, or
electrocardiograph. In some countries, the
abbreviation used is ‘EKG’.
• Each event has a distinctive waveform
• The study of waveform can lead to greater insight
into a patient’s cardiac pathophysiology

9. (40-60 beats per
minute )
(60-100 beats
per minute )
(20-45 beats
per minute )

12. • ECG Paper
Thermal paper
Calibration
• ECG machine- stylus records on thermal
paper,which moves at a fixed speed of
25mm/sec
(can be changed)

17. Einthoven Rule
I+II+III=0
I+(-II)+III=0
I+III=II

21. Electrical impulse that travels towards the electrode
produces an upright (“positive”) deflection

34. The QRS Axis
The QRS axis represents overall direction of
the heart’s electrical activity.
Abnormalities hint at:
Ventricular enlargement
Conduction blocks (i.e. hemiblocks)

36. Determining the Axis
• The Quadrant Approach
• The Equiphasic Approach
• Lead I and III Approach

42. Lead I and III
• Left Leaves
• Right Approaches
Lead I
Lead III
Lead I
Lead III

55. ECG Criterias for Chamber
Enlargement

56. Atrial Enlargement

60. Left Ventricular Hypertrophy

63. Sokolow-Lyon voltages
•SV1 + R V5,6 > 3.5 mV
(Sensitivity 22%,Specificity 100 %)
•R aVL > 1.1 mV
•R V5,6 > 2.6 mV

65. Right Ventricular
hypertrophy

66. • Sokolow Lyon criteria for RVH:
– R V1 + S V5, V6 > 10.5 mm
– R V1 > 7 mm
– R in aVR > 5mm
– S V1 < 2mm

68. Summary
1. Look for aVR
2. Heart Rate
3. P-wave morphology-lead II(0.12-0.20 sec)
4. pR interval (3-5 small sqaures)
5. QRS wave and duration(0.8 to 0.12)(2 to 3 small sqaures)
6. q wave
7. Chest lead-R wave progression
8. ST segment
9. T wave morphology
10. Ectopic beat and other abnormalities
Your eyes can’t see if your mind doesn’t know…..so practice and
learn….