Einthoven, Sir Thomas Lewis, and others correlated the ECG waves with the contracting heart and correlated that
The P wave was related to atrial contraction and
The QRS deflection was associated with ventricular contraction
Outline
❑ Introduction toECG or EKG
❑ History of EKG/ECG
❑ Galvani,1790
❑ Mid 1880’s, Ludwig and Waller
❑ Research by Dr. Willem Einthoven & invention of
ECG Machine
❑ Einthoven, Sir Thomas Lewis
❑ Frank Wilson, 1934
3.
Introduction to
ElectroCardioGram
(ECG orEKG)
▪The graphic representation of the heart’s
electrical activity recorded through electrodes
positioned at strategic points on the body
constitutes the electrocardiogram (ECG or EKG).
▪Electrocardiography is the process
of producing an
electrocardiogram (ECG or
EKG).
▪ EKG is the German spelling for
elektrokardiographie
4.
Electrocardiograph:
The machine bywhich the
electrical activities of heart recorded.
Electrocardiographic paper:
Used for recording ECG
is known as ECG paper.
Electrocardiographic Grid:
Refers to the marking (lines) on ECG paper.
ECG paper has horizontal and
verticals lines at regular intervals
of 1mm and every 5th
line (5mm) is thickened.
5.
Introduction (Cont..)
▪The recordingof the electrical currents, their
direction, and their magnitude, as well as
the rate of the heart’s contractions, is
made by the machine and
electrocardiograph.
▪The ECG is the recording obtained,
and displays the following:
• Three major deflections or waves:
▪The P wave, the QRS complex, and a T
wave
▪Two intervals of clinical importance:
▪The PR interval and QRS duration
6.
History of ECG
Galvani,1790
▪In1790 Luigi Galvani made dead frog’s
legs dance by electrical
stimulation.
▪Galvani knew that completing a circuit
connecting dissimilar metals to the legs of
a recently deceased frog would create
stimulating electrical current.
▪The resulting electrical current would
stimulate the frog’s legs to jump, and with
repeated stimuli he could make them
dance.
7.
Kollicker and Mueller,1855-56
▪In 1855, Kollicker and Mueller found
that a motor nerve to a frog’s leg
was laid over its isolated beating
heart, the leg kicked with each
heartbeat.
▪They thought “the same electrical
stimulus that causes a frog’s leg
to kick must cause the heart
to beat.
▪ So, it was logical for them to
assume that the beating of the
heart must be due to a rhythmic
discharge of electrical stimuli.
8.
Mid 1880’s, Ludwigand Waller
▪In the mid 1880’s, while using a “capillary
electrometer” Ludwig and Waller
discovered that the heart’s rhythmic
electrical stimuli could be monitored from
a person’s skin.
▪However, their apparatus was not sensitive
enough for clinical use.
▪This achievement opened the door for
recording the heart’s electrical activity from the
skin.
9.
Research by Dr.Willem Einthoven
▪Einthoven recognized that the
heart possessed electrical activity.
▪He recorded this electrical activity
using two sensors attached to the two
forearms and connected to a silver
wire that ran between two poles of a
large permanent magnet.
▪He noted that the silver wire
moved rhythmically with the
heartbeats.
10.
Invention of EKGMachine by Einthoven in 1901
▪For the visualization of the silver wire
small movements, Einthoven shone
a light beam across the wire,
and the wavy movements of the
wire were recorded on moving
photographic paper.
▪Einthoven recorded the waves and
spiky deflection and labeled the first
smooth, rounded wave, P; the spiky
deflection, QRS; and the last
recorded wave,T.
11.
Einthoven, Sir ThomasLewis
▪Einthoven, Sir Thomas Lewis, and others correlated the
ECG waves with the contracting heart and correlated that
▪The P wave was related to atrial contraction and
▪The QRS deflection was associated with
ventricular contraction.
12.
Frank Wilson, 1934
▪FrankWilson, who studied with Lewis, in Michigan
(1934), described the unipolar leads that include
the precordial V leads and VR, VL, and VF.
13.
Reference
▪Rapid ECG interpretationby Mr. M. Gabriel Khan 3rd
edition
(Chapter # 01)
▪Rapid interpretation of EKG by Dale Dubin 6th
edition(Chapter # 01)