The document provides an overview of electrocardiograms (ECG), including their function in monitoring heart activity through electrical impulses. It outlines the historical development of ECG technology, significant scientists involved, and the interpretation of heart rhythm through defined waves (PQRST). Additionally, it discusses various clinical uses of ECG, including diagnosing heart conditions and the effects of medication.

1. ECG
HARINI.V
2ND MSC ZOOLOGY

2. We are probably familiar with this scene from a typical hospital
television shows ; a patient is hooked up to a monitoring machine
that shows voltage traces on a screen and makes the sound
‘…pip…pip…pip….peeeeeeeeeeeee’ as the patient goes into cardiac
arrest. This type of machine (electro-cardiograph)is used to obtain
an electrocardiogram (ECG)

3. ECG - ELECTROCARDIOGRAM
ELECTRO – ELECTRICITY
CARDIO- HEART
GRAM- VISUALIZE
A medical device which is used to measure and monitor the rate and
regularity of heartbeats.
The heart is made to beat by an electrical impulse orginating in the
sinus auricular node.
EINTHEN WILLEM is the FATHER OF ECG

4. HISTORY

5. HISTORY
▪ 1842- Italian scientist Carlo Matteucci realizes that electricity is
associated with the heart beat.
▪ 1876- Irish scientist Marey analyses the electric pattern of frog’s
heart.
▪ 1895- William Einthoven , credited for the invention of EKG
▪ 1906- using the string electrometer EKG, William Einthoven
diagnoses some heart problem.

7. • 1938- AHA and Cardiac society of great Britain defined and
position of chest leads.
• 1942- Goldberger increased Wilson’s unipolar lead voltage by 50%
and made augumented leads.

9. INDICATIONS
▪ Myocardial infarction & other types of CAD such as angina
▪ Cardiac dysrhythmias
▪ Cardiac enlargement
▪ Inflammatory diseases of the heart
▪ Effects on the heart by drugs, such as antiarrythmics.

10. CONDUCTION OF THE HEART BEAT

11. INHERENT RATE

12. ▪ ECG machine amplifies and records the electrical activity of the
heart.
▪ The electrical activities are recorded on a paper called ECG PAPER
▪ The machine is connected to the surface skin of the body through
ELECTRODES called ECG LEADS.

13. LEAD SYSTEM
A 12- lead ECG provides multiple electrical views of the heart along
a vertical and horizontal plane.
LIMB LEADS- 6
CHEST LEADS- V1,V2,V3,V4,V5 &V6

14. ▪ The electrocardiogram of man shows a series of WAVES. The
waves represent the sequence of Depolarization and
Repolarization of the auricles and ventricles. Each ECG has 5
consecutive waves, namely 3 UPWARD WAVES or POSITIVE WAVES
and 2 DOWNWARD WAVES or NEGATIVE WAVES. They are named
as PQRST.
▪ upward deflections- P,R &T
▪ Downward – Q& S

15. Add a Slide Title - 2

16. P WAVE
▪ Positive wave
▪ It is also called as ATRIAL COMPLEX
▪ FIRST WAVE
▪ It represents the wave of DEPOLARISATION that spreads from
SINOAURICULAR NODE throughout auricles.
▪ It is a small wave with a rounded top.
▪ It takes place when the impulse spreads over the atrial chambers.
▪ Average duration- 0.1 second

17. QRS
▪ Ventricular depolarization
▪ Initial ventricular complex
▪ Average duration- 0.06 to 0.1 sec.

18. Q WAVE
▪ FIRST DOWNWARD WAVE
▪ The impulse arrives at the interventricular septum and the septum
contracts.

19. R WAVE
▪ 2ND Upward deflection
▪ It represents the activity of RIGHT VENTRICLE.
▪ It is a conspicuous wave with the tallest amplitude.

20. PR AND QR INTERVAL
▪ PR INTERVAL
period from beginning of P WAVE to beginning of Q wave.
PR interval lasts 0.16 sec
▪ QT INTERVAL
PERIOD FROM BEGINNING OF Q WAVE TO END OF THE T WAVE.
it represents the entire periods of depolarization and
repolarization of ventricle.
interval lasts 0.35 sec

21. S WAVE
▪ SECOND DOWNWARD WAVE
▪ It represents the activity of LEFT VENTRICLE.

22. T WAVE
▪ REPOLARISATION WAVE OF THE VENTRICLE.
▪ Third upward deflection.
▪ Duration-0.27 seconds

23. USES OF ECG
▪ Heart beat rate
▪ Heart rhythm
▪ Abnormal electrical conduction
▪ Poor blood flow to heart muscles
▪ Heart attack
▪ Position of chambers
▪ Coronary artery disease
▪ Effect of drugs

26. THANK YOU