Heart sound is produce by mechanical activities of
the heart during each cardiac cycle.
Heart sound is produce by movement of –
1. Blood through the chambers of heart.
2. Contraction of Cardiac muscle.
3. Valves of the heart.
4. Turbulent blood flow.
All these factor produce vibration & its produce
heart sound .
Heart sound are heard by placing the stethoscope
over the chest.(I & II only).
Heart sound recorded graphically.
Heart sound are four types.
Cause : due to closure of Atrio ventricular valves.
Character :long, soft & low pitched ,resembles the
Duration : 0.10 -0.17 sec.
Frequency : 25-45 cycles/sec.
Occurs during cardiac cycle : Isometric contraction
period & part of ejection period.
Relation with ECG :coincides with peak of “R” wave
No of vibration in phonocardiogram: 9 -13
Cause : closure of semi lunar valves .
Character : short , sharp & high pitched. resembles
the word “DUB”.
Duration : 0.10-0.14 sec.
Frequency: 50 cyc/sec.
Occurs during cardiac cycle: ProtoDiastole .
Relation with ECG: peak of “T” wave.
No of vibration in phonocardiogram : 4-6
Cause : due to Rushing of blood in to ventricles.
Character : Low pitched .
Duration : 0.07 -0.10 Sec.
Frequency : 1-6 Sec.
Occurs during cardiac cycle : Rapid Filling phase.
Relation with ECG: betn T wave & P wave .
No of vibration in phonocardiogram :1-4
Cause : due to contraction of Atrial muscle.
Character : inaudible sound
Duration : 0.02 -0.04 sec.
Frequency: 1-4 cyc/sec.
Occurs during cardiac cycle : Atrial systole
Relation with ECG: betn “P” wave & “Q” wave.
No of vibration in phonocardiogram: 1-2
The first & second
heart sound heard by
placed on 4 area on
the chest K/a
1. Mitral area (Bicuspid
Area): In the left 5th
intercostal space , 10
cm away from mid
clavicular line .(area
of apex beat)
- 1st heart sound
3. Pulmonary Area : on the left 2nd intercostal space
close to sternum.
- 2nd Heart sound heard (closure of pulmonary
4. Aortic area : over the right 2nd intercostal space
close to sternum.
- 2nd Heart sound heard (closure of Aortic valve).
2. Tricuspid area : on the xiphoid
- 1st heart sound heard.(closure of
All four Heart sound is Recorded by use of Phonocardiogram
Cardiac murmur is the abnormal heart sound .
It produce due to turbulent blood flow.
- cause of turbulent blood flow:
* valvular disease
* septal defects
* vascular defects
Valvular disease are two type
- means narrowing of the heart valve. so blood
flow are rapidly & turbulence
- means weakening of the valve of heart so it
cannot close properly causes back flow of blood
Cardiac murmur are three types :
1. Systolic murmur –
* Incompetence of A-V valve
* Stenosis of semi lunar valve
* septal defect
2. Diastolic murmur –
* Stenosis of A-V valve
* Incompetence of semi lunar valve.
3. Continuous murmur
causes – * patent ductus arteriosus.