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Elektrokardiografi
SA node AP
• Unique, rhythmic
action potentials at
the SA node.
• Depolarization:
– VG fast Ca2+
channels
• Repolarization:
– VG K+ channels.
Myocardial APs
• SA node spreads APs
to myocardial cells.
• Depolarization: VG
Na+ channels
• Plateau phase: VG
slow Ca2+ channels
open.
– Slow inward Ca2+
balances outflow of
K +.
• Repolarization: VG K+
channels.
Myocardial APs
THE ELECTROCARDIOGRAM AND ACTION POTENTIAL
1.0
+40
R
0
0.5
The time course of the
intracellular action
potential has been
superimposed on the
electrocardiogram
T
P
0
-80
Q
mV
mV
S
0
200
400 ms 600
Note that the:
upstroke of the action
potential coincides with
the QRS complex
repolarisation of the
action potential
coincides with the T
wave
The Heartprint:Waves
HIZ
0.2 sn
0.04 sn
Normal kağıt hızı 25 mm/sn
Rate – The Paper
150
300
75
100
60
Or look at the right upper corner for the rate
or look at the monitor for the rate
Measure the rate by the distance between QRS complexes
Electrocardiogram (ECG/EKG)
• Note: Tissue fluids
conduct electricity.
• EKG:
– Measure of the
electrical activity
of the heart.
ECG
• P wave:
– Atrial depolarization,
contraction.
• QRS complex:
– Ventricular
depolarization,
contraction
– Atrial repolarization.
• T wave:
– Ventricular
repolarization.
Summary
• Systole
– Lub (AV closes)
– ~ QRS to T
– Ventricles contract
• Diastole
– Dub (semilunar
close)
– T to ~ QRS
– Ventricles relax
1. Sinoatrial nod
2. Atrioventriküler nod
3. Atrioventrikuler Demet
4. His
5. Purkinje
Sinoatrial
nod
Sol atrium
His demeti
Sağ atrium
Sol ana dal
Atrioventriküler
nod
Sol posterior
fasikül
Sağ ana dal
Sol vetrikül
Sol anterior
Sağ ventrikül
fasikül
Purkinje
lifleri
Kardiak İleti Sistemi
Voltaj
Süre
RR intervali
QRS kompleki
T dalgası
P dalgası
ST segmenti
U dalgası
Depolarizasyon Dalgası
-
+
EKG
+++++++++++++++
-------------------Dinlenim
-
Dinlenim
0 mV
+
EKG
----- +++++++++++
++++--------------Depolarizasyon   0 mV
+
EKG
-------------------+++++++++++++++
Depolariazasyonun Bitişi
+ 1 mV
Depolarizasyon
Başlaması
-
+ 1 mV
0 mV
Depolarizasyon
Bitişi
Repolarizasyon Dalgası
-
+
EKG
-------------------+++++++++++++++
Dinlenim
-
Depolarizasyon Bitişi
0 mV
+
EKG
---------------+++++
+++++++++++-----    Repolarizasyon 0 mV
-
+
EKG
+++++++++++++++
- - - - - - - - - - - - - - - - - - - - 0 mV
Repolarizasyon Bitişi
+ 1 mV
Repolarization
Başlaması
+ 1 mV
Repolarizasyon
Bitişi
Depolarizasyon dalgası
Repolarizasyon Dalgası
Base
EKG
Repolarizasyon
Depolarizasyon
+
Apex
Normal bir kalbin elektriksel axisi
(-)
Base
Elektriksel Axis
Apex
(+)
Normal Axis
-30° to 90°
-30°
90°
DI
0°
D II
60°
D III
120°
aVF
90°
aVL
-30°
aVR
-150°
Axis
-150° aVR
-30° aVL
0° I
60° II
120° III
90° aVF
Axis Tayini
Most isoelectric lead? aVF
Positive or negative? Positive
aVF is 90° The axis is perpendicular to this and is 0°
Axis Practice – What is the axis?
Most isoelectric lead? D II
Positive or negative? Positive
II is +60° The axis is perpendicular to this and is -30°
Sol kol
Sağ kol
Sol bacak
Intervaller
PR interval
Normal aralığı
0.12 to 0.20 sec
QT interval
Normal range
<.45 sec
INTERPRETING THE ELECTROCARDIOGRAM

1.0
S
R
0.5
QT
T
P
0
Q
mV
PR
0
QRS ST
200
400 ms 600
PR interval - 0.12 - 0.20 s
determined by delay of the AP at
the a-v node.
 QRS complex time - 0.08 s
the time for AP propagation
along the conduction system
 ST segment. Isoelectric
region corresponding to the
ventricular AP plateau
 QT interval. The mean
duration of the ventricular AP.
Interval is heart rate dependent.
 QTc = QT/√RR is relatively
independent of heart rate.
1 2 3
4
5
6
120
Pressure
mm Hg
7
THE CARDIAC
CYCLE
80
atrial systole
40
Aortic
flow
l.min-1
25
0
•Ventricle are
full of blood
•Pressure low in
the ventricle
•P wave on the
e.c.g.
0
140
Ventricular
volume, ml
70
1
4
a
heart sounds
venous pulse
R
P
e.c.g.
Q
0
0.5
1.0 s
1 2 3
4
5
6
120
Pressure
mm Hg
25
0
THE CARDIAC
CYCLE
80
40
Aortic
flow
l.min-1
7
0
isovolumic
contraction
mitral
valve
closes
•The ventricle
contracts
•Pressure rises in
the ventricle
•Mitral valve
closes
•QRS complex
on the e.c.g.
•1st heart sound
heart sounds
140
Ventricular
volume, ml
70
1
4
a
venous pulse
R
P
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
40
Aortic
flow
l.min-1
25
0
0
4
5
6
aortic
valve
opens
7
THE CARDIAC
CYCLE
ejection
mitral
valve
closes
•The aortic valve
opens
•Blood ejected
into the aorta
•T wave at the
end of the period
on the e.c.g.
140
Ventricular
volume, ml
70
1
4
a
2
heart sounds
c
venous pulse
R
P
T
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
40
Aortic
flow
l.min-1
25
0
0
4
5
6
aortic
valve
opens
7
aortic valve
closes
THE CARDIAC
CYCLE
isovolumic
relaxation
mitral
valve
closes
•The ventricle
relaxes
•Aortic valve
closes
•Pressure falls in
the ventricle
•2nd heart sound
140
Ventricular
volume, ml
70
1
4
a
2
heart sounds
v
c
venous pulse
R
P
T
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
40
Aortic
flow
l.min-1
25
0
0
4
5
6
aortic
valve
opens
7
aortic valve
closes
THE CARDIAC
CYCLE
Filling
mitral
valve
closes
mitral valve
opens
•The ventricle
has relaxed
•Pressure is low
in the ventricle
•Mitral valve
opens
•Ventricles fill
with blood
140
Ventricular
volume, ml
70
1
4
a
2
3
heart sounds
v
c
venous pulse
R
P
T
Q
0
P
S
0.5
e.c.g.
1.0 s
1 2 3
4
5
6
120
Pressure
mm Hg
7
THE CARDIAC
CYCLE
80
atrial systole
40
Aortic
flow
l.min-1
25
0
•Ventricle are
full of blood
•Pressure low in
the ventricle
•P wave on the
e.c.g.
0
140
Ventricular
volume, ml
70
1
4
a
heart sounds
venous pulse
R
P
e.c.g.
Q
0
0.5
1.0 s
1 2 3
4
5
6
120
Pressure
mm Hg
25
0
THE CARDIAC
CYCLE
80
40
Aortic
flow
l.min-1
7
0
isovolumic
contraction
mitral
valve
closes
•The ventricle
contracts
•Pressure rises in
the ventricle
•Mitral valve
closes
•QRS complex
on the e.c.g.
•1st heart sound
heart sounds
140
Ventricular
volume, ml
70
1
4
a
venous pulse
R
P
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
40
Aortic
flow
l.min-1
25
0
0
4
5
6
aortic
valve
opens
7
THE CARDIAC
CYCLE
ejection
mitral
valve
closes
•The aortic valve
opens
•Blood ejected
into the aorta
•T wave at the
end of the period
on the e.c.g.
140
Ventricular
volume, ml
70
1
4
a
2
heart sounds
c
venous pulse
R
P
T
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
40
Aortic
flow
l.min-1
25
0
0
4
5
6
aortic
valve
opens
7
aortic valve
closes
THE CARDIAC
CYCLE
isovolumic
relaxation
mitral
valve
closes
•The ventricle
relaxes
•Aortic valve
closes
•Pressure falls in
the ventricle
•2nd heart sound
140
Ventricular
volume, ml
70
1
4
a
2
heart sounds
v
c
venous pulse
R
P
T
Q
0
e.c.g.
S
0.5
1.0 s
1 2 3
120
Pressure
mm Hg
80
4
5
6
aortic
valve
opens
7
aortic valve
closes
THE CARDIAC
CYCLE
Filling
40
Aortic
flow
l.min-1
25
0
•The ventricle
has relaxed
•Pressure is low
in the ventricle
•Mitral valve
opens
•Ventricles fill
with blood
0
140
Ventricular
volume, ml
70
1
a
2
3
heart sounds
v
c
venous pulse
R
P
T
Q
0
P
S
0.5
e.c.g.
1.0 s
HEART SOUNDS
Of four heart sounds only
two (S1 & S2) generally are
heard with a stethoscope.
aortic
pressure
ventricular
pressure
atrial
pressure
S1 is generally the longest
and loudest. It occurs at the
beginning of systole.
S2 occurs at the end of
ventricular systole.
volume
S3 is low pitched and occurs
early ventricular filling.
S4 S1
S2
S3
S4 is coincident with atrial
contraction
PQRST waves
R
P
T
Q
PR
QT
PQRST dalgaları
P
PR
R
S
T
QT
1. Bütün QRS den önce P dalgası var
2. Düzenli
EKG Leads
• The 12 EKG leads measure the electrical
activity of the heart from 12 different
directions
• Bipolar Leads: Lead I, Lead II, Lead III
• Unipolar Leads: aVR, aVL, aVF
• Precordial Leads: V1, V2, V3, V4, V5, V6
Precordial Leads (V1 to V6)
Right Arm
+
+
+
-
+
+
+
Left Arm
V1
V2
V3
V4
V5
V6
Left Leg
Directionality of Bipolar and
Unipolar Leads
aVL
aVR
Lead I
Lead II
Lead III
aVF
Basic EKG Interpretation
• EKG Waves (P, QRS, and T waves)
• EKG Intervals (P-R, Q-T intervals)
S-A blok
Deprese S-T segment
Deprese segment S-T
ischemie myokard
DCM
DCM
(RBBB)
DCM
DCM
A-V blok III.st.,A-V disociace
IQ myokard
Perikardit
Ischemia or Infarction
• ST segment elevation = Infarction
• ST segment depression = Ischemia
Anterior Ischemia
• ST segment elevation
– V3 and V4
• Reciprocal changes (ST depression)
– II, III, AVF
Septal Ischemia
• ST segment elevation
– V1 and V2
Anteroseptal
• ST segment elevation
– V1 through V4
• Reciprocal changes (ST depression)
– II, III, AVF
Inferior Ischemia
• ST segment elevation
– II, III, aVF
• Reciprocal changes (ST depression)
– V1 through V4
Lateral Ischemia
• ST segment elevation
– I, aVL, V5 and V6
• Often associated with anterior ischemia
• Reciprocal changes (ST depression)
– II, III, AVF
Posterior Ischemia
• Easy to miss!
• Tall R wave in V1 and V2
• ST segment depression in V1 through
V4
• If you hold the EKG up to a bright light
and turn it over you will see the classic
ST elevation.
Ventricular Fibrillation
Lange Fig 28-15
R Axis Deviation
http://medlib.med.utah.edu/kw/ecg/ecg_outline/Lesson8/#RVH
Atrial flutter
http://www.ecglibrary.com/aflut.html
Atrial flutter with 2:1 AV conduction
http://www.ecglibrary.com/af2_1.html
QRS abnormalities
•
•
•
•
ST depression
ST elevation
T wave inversion
Q wave
=
=
=
=
ISCHEMIA
INJURY
late ISCHEMIA
INFARCT
Acuter Anterior Infarction
http://www.ecglibrary.com/ami.html
Evolution of ECG infarct
access Lange Ch28fig19
Ventricular Tachycardia
Lange Fig 28-14
Io Block
http://www.dr-boesch.ch/medicine/ekg/ekg-teil3-erregungsausbreitung3.htm
2o Block Mobitz I
http://www.dr-boesch.ch/medicine/ekg/ekg-teil3-erregungsausbreitung3.htm
2o Block Wenkebach I
http://www.dr-boesch.ch/medicine/ekg/ekg-teil3-erregungsausbreitung3.htm
Complete Heart Block
Right Bundle Branch Block
http://www.ecglibrary.com/rbbb.html
Rhythm?
Bradycardia, rate 40/min
Anterior MI, early
Taken a few hours later…