The document provides an overview of the electrocardiograph (ECG), its function, and key concepts related to heart electrical activity. It describes the different leads used in ECG, the significance of various waves and intervals, and their normal durations, along with conditions that may cause prolongation or shortening of these intervals. Additionally, it covers how to calculate heart rate based on R-R intervals.

1. Doon Ayurvedic medical college and hospital
[ Saharanpur ]
Guide by – Dr. Anu Bhardwaj
{ B. A. M. S. , M.D. Ayu. }
Perform by – Rajdeep Singh
{ Batch – 2023-24 }

2. Introduction –
– Electrocardiograph .
- Electrocardiograph is the instrument
(machine) by which electrical activities of
the heart are recorded .
- Discovered - Einthouen Leuwenhock .
- Function - Measure heart electric
activity .
- Principle- Galvenometer .

3. 2. USE –
- Diagnosis of chest pain .
- Diagnosis the breathlessness .
- Dignosis of cardiac problems
.

4. 3. Lead - Leads Total 12
- Two type of leads
- Chest lead -6
- Limb lead- Biplolar-3,
- Armented lead -3

5. Chest lead –
V1 - Right Side in 4th intercostal Space.
V2 - Left Side in 4th intercostal Space.
V3 - Between V2 and V3 .
V4 - Left Mid clavicular line in 5th
Intercostal Space.
V5.- Medially axillary line in 5th
Intercostal Sapce.
V6. - Laterally axillary line in 5th
Intercostal Space.

7. Limb lead-
(a) Bipolar limb lead
Lead I -
Lead II-
Between the right arm and left arm
Between the right arm and left leg.
Lead III - Between left arm and left leg.

8. (b) Unipolar limb lead-
Avr - Right arm avl -Left arm avf - Left foot
(av, -Armented voltage foot)

9. ECG waves –
P wave-
T Wave-
Atrium /Articular Depolarisation .
Ventericular Repolarisation .
QRS Complex - Ventricular Depolarisation .
Interval and Segments –
1. P-R interval
3. P-R segment
5. R-R interval
7. P-P interval
2. Q-T interval
4. S-T
interval
6. S-T interval

10. Interval- Starting point of wave to ending
point of wave. Interval always big.
eg. PR interval- Starting point ofPwave to
ending point of R wave.
-Segment- Ending point ofwave to starting
point ofwave.
-eg. PR Segment - Ending point ofP wave to
starting point of R wave.
-Cardiac cycle -0.8 sec
-PR interval -0.2 sec
-Systol 0.6 sec
-Diastole 0.2 sec

11. Waves of normal ECG –

13. P-R INTERVAL –
= P-R interval is the interval between
the onset of'P' wave and onset ofQ' wave.
= It's significes the aterial devpolarisation
and conduction impulses through the A-V
nodes.
= Normal duration ofP-R interval -0.18
second (0.12 to 0.20)

14. = Prolonged P-R interval scen in
bradycardia and first degree heart block.
= Shortend P-R interval seen in
tachycardia, WPW syndrome and LGL
syndrome.

15. Q-R interval-
= Q-T interval is the interval between
onset of'Q' wave and onset of T' wave. It
indicats the ventricular depolarisation
and repolarisation.
=It's significes the electrical activity in
venrticles.
=Normal duration ofQ-T interval is
between 0.4 to 0.42 seconds.

16. =In long, Q-T Syndrome, Q-T Interval is
prolonged ie. present in myocardial
infarction, myocardities, hypothyroidism
and hypocalcaemia.
= In shrot Q-T syndrome, Q-T interval is
shortend i. e. present in hypercalcaemia.

17. P-R Segment –
= It is an isoelectric period and the time
interval between end of"P' wave and
beginning of QRS Complex.
= P-R segment indicates the atrial
depolarisation and delay in the
AVjunction.
= Normal duration P-R segment - 0.12 - 0.20
seconds.

18. =Depression ofbareline up to 0.8 mm
accepted as normal.
= Pathological depression ofP-R segment
occurs in pericarditis and artial ischemia.

19. S-T Sgement –
= It is an isoelectric preiod, and the time
interval between end of's' wave and the
onset of't' wave.
= Normal duration of"S-T' segment is 0.05
second.
= Elevation of"S-T' segment occurs in
anterior or inferior myocardial infection
and left bundle branch block.

20. = In athelets 'S-T' segment is usually
elevated.
= Depression of"S-T' segment occurs
in posterior or mycoardial infarction
and hypokalemia.
="S-T Segment is prolonged in
hypocalcemia.

21. R-R interval –
= The time interval between two
consecutive 'R' waves is R-R interval.
= Normal duration of R-R interval is 0.8
second.
= Measurement of R-R interval helps in
calculation of heart rate and heart rate
Variability .

23. Heart rate -
Regular rhythm = 300/ Laege box between
R-R interval .
Rate = 300 / 4
= 75 bpm
Irregular rhythm =
[ No. of R waves in 6 sec ][ 10 ]

24. Animation