1. Cardiovascular system- L3
Faisal I. Mohammed, MD, PhD
Yanal A. Shafagoj
University of Jordan

2. Electrocardiogram ECG or EKG
Composite record of action potentials produced by all the heart muscle fibers
Compare tracings from different leads with one another and with normal records
3 recognizable waves
P, QRS, and T
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3. The Electrocardiogram
The major deflections and intervals
in a normal ECG include:
P wave - atrial depolarization
P-Q interval - time it takes for
the atrial kick to fill the
ventricles
QRS wave - ventricular depolarization
and atrial repolarization
S-T segment - time it takes to empty the ventricles before they repolarize (the T wave) 3

4. Correlation of ECG Waves and Systole
Systole means ventricular contraction and diastole means ventricular relaxation. Cardiac cycle events are:
Cardiac action potential arises in the SA node → P wave
Atrial systole (Atrial contraction)
Action potential enters AV bundle and leaves to the ventricles → QRS complex which masks atrial repolarization (un-recordable)
Contraction of ventricles (systole)
Begins shortly after QRS complex appears and continues during S-T segment
Repolarization of ventricular fibers → T wave
Ventricular relaxation/ diastole
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5. Cardiac Cycle All events associated with one heartbeat
Systole and diastole of atria and ventricles
In each cycle, atria and ventricles alternately contract and relax
During atrial systole, ventricles are relaxed
During ventricle systole, atria are relaxed
Forces blood from higher pressure to lower pressure
During relaxation period, both atria and ventricles are relaxed
The faster the heart beats, the shorter the relaxation period
Systole and diastole lengths shorten slightly
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6. Cardiac Cycle
Cardiac cycle refers to all events associated with blood flow through the heart
Systole – contraction of heart ventricles
Diastole – relaxation of heartventricles 6

7. Cardiac Cycle 7 Atrial systole 0.1 second Atrial diastole 0.7 second
Ventricular systole 0.3 second
Isovolumic contraction phase
Rapid ejection period
Slow ejection period
Ventricular diastole 0.5 seconds
Rapid filling phase
Slow filling (Diastasis)
Atrial contraction phase 7

8. Phases of the Cardiac Cycle8

9. University of Jordan 9 20 40 60 80 100 120 (d) Volume in20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
Stroke
volume
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 4 7 1 2 3 5 6
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction
Begin ventricular ejection
End (ventricular) systolic volume 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 4 6 1 2 3 5
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction
Begin ventricular ejection 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
Stroke
volume
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 8 1 2 3 4 5 6 7
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction
Begin ventricular ejection
End (ventricular) systolic volume
Begin ventricular repolarization 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
Stroke
volume
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 8 9 1 2 3 4 5 6 7
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction
Begin ventricular ejection
End (ventricular) systolic volume
Begin ventricular repolarization
Isovolumetric relaxation 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
Stroke
volume
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 10 1 2 3 4 5 6 7 8 9
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction
Begin ventricular ejection
End (ventricular) systolic volume
Begin ventricular repolarization
Isovolumetric relaxation
Ventricular filling 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 4 5 1 2 3
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization
Isovolumetric contraction 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 4 1 2 3
Atrial depolarization
Begin atrial systole
End (ventricular) diastolic volume
Ventricular depolarization 1 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4
Atrial depolarization 1 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 2
Atrial depolarization
Begin atrial systole 1 20 40 60 80
100
120
(d) Volume in
ventricle (mL)
(c) Heart sounds
(b) Pressure
(mmHg)
(a) ECG P R Q S
Dicrotic wave
Left atrial
pressure
Aortic
Left
ventricular T
130
Atrial
contraction
Isovolumetric
relaxation
Ventricular
ejection
filling
(e) Phases of the
cardiac cycle
End (ventricular) diastolic volume
0.3 sec
0.1
sec
0.4 sec
systole
Relaxation
period S1 S2 S3 S4 2 3
Atrial depolarization
Begin atrial systole
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10. 10

11. Stroke Volume
SV = end diastolic volume (EDV) minus end systolic volume (ESV)
EDV = amount of blood collected in a ventricle at the end of diastolic phase
ESV = amount of blood remaining in a ventricle after contraction 11

12. Cardiac cycle …cont
End diastolic volume (EDV) – End systolic volume (ESV) = Stroke volume (SV)
SV X heart rate (HR) = cardiac output (CO)
Ejection fraction = SV/EDV
Autonomic control of cardiac cycle (pump) 12

13. Cardiac Output
CO = volume of blood ejected from left (or right) ventricle into aorta (or pulmonary trunk) each minute
CO = stroke volume (SV) x heart rate (HR)
In typical resting male
5.25L/min = 70mL/beat x 75 beats/min
Entire blood volume flows through pulmonary and systemic circuits each minute
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14. Thank You 14