Heart sound 1

Heart sounds

Sounds produced due to closure or opening of heart valves

Cardiac cycle

Sequence of events occurring during one heartbeat

Atrial systole

Phase where atria contract and fill ventricles

Percentage of ventricular filling by atrial systole

30% of ventricular filling

Percentage of ventricular filling during diastole

70% of ventricular filling

Effect of atrial fibrillation on ventricular filling

Absent atrial contraction → decreased ventricular filling → decreased cardiac output → hypotension

Major complication of atrial fibrillation

Clot formation → embolism → acute ischemic stroke

Isometric contraction

Cause of first heart sound (S1)

Closure of mitral and tricuspid valves

Timing of S1

at End of atrial systole /at start of isovolumetric contraction

Mnemonic for S1

M1T1

Isovolumetric contraction

Phase where ventricles contract but no blood enters or leaves

Valve status during isovolumetric contraction

All valves closed

Ventricular pressure during isovolumetric contraction

Pressure starts building up

Valve bulge after isovolumetric contraction

Slight bulge in mitral and tricuspid valves

Ventricular systole

Ventricular contraction pattern in ventricular systole

Both ventricles contract simultaneously with equal force

Stroke volume during ventricular systole

Approximately 80 ml

Valves opening during ventricular systole

Aortic and pulmonary valves

Ejection click

Produced due to opening of aortic and pulmonary valves

Ejection click is seen in

• Normal

• Aortic stenosis

Cause of pulmonary edema in LV dysfunction

Reduced blood ejection → pooling → pulmonary edema

Isovolumetric relaxation

Cause of second heart sound (S2)

Closure of aortic and pulmonary valves

Timing of S2

End of ventricular systole

Components of S2

A2 and P2

Valve bulge during S2

Absent bulge of mitral and tricuspid valves

Cause of valve behavior in S2

Decompression of ventricles

Isovolumetric relaxation

Phase where heart relaxes with all valves closed

Valve status during isovolumetric relaxation

Mitral, tricuspid, aortic and pulmonary valves closed

Rapid ventricular filling phase

Initial phase of diastole where blood flows rapidly into ventricles

Maximum filling occur in which phase of cardiac cycle

rapid ventricular filling

Percentage of filling during rapid ventricular filling

70% of ventricular filling

Valves opening during rapid ventricular filling

Mitral and tricuspid valves

Opening snap

Sound produced due to opening of stenosed AV valves

Cause of loud opening snap

Mitral stenosis or tricuspid stenosis

Gap between second heart sound

splitting of 2nd heart sound

Time lag between A2P2 splitting

30 msec

Full linear diagram of sound, systole, diastole

Between s1 and s2

ventricular systole

What is protodiastole?

period between end of systole to closure of A2P2 ( valve need some time to close )

Phase just after s2

protodiastole

Period between s2/protodiastole till opening snap

IVR (isovolumetric relaxation)

Phase after IVR

rapid ventricular filling

Sound in rapidventricular filling

S3

Other name of 3rd heartsound

ventricular gallop rhythm

Diastasis

Phase of minimal ventricular filling

Least movement of heart present in

diastasis

Meaning of diastasis

Heart appears to stand still

Systole duration

S1 to S2

Systole phase present between

S1 to S2

Diastole duration

S2 to S1

Phases in diastole

1. Protodiastole

2. IVR

3. Rapid ventricular filling

4. Diastasis

5. Atrial systole

All events chart in video

Protodiastole

Early diastolic phase immediately after S2

Splitting of S2 more prominent in

inspiration

Third heart sound (S3)

Occurs during rapid ventricular filling

Cause of S3

Blood hitting ventricular wall

Age significance of S3

Physiological in

Fourth heart sound (S4)

Occurs during atrial systole

Other name of 4th heart sound

atrial gallop rhytm

Which heart sound present before S1

s4

Cause of S4

Pathological stiff ventricle

Gallop rhythm

Combination of abnormal heart sounds (S3 or S4)

Time gap between A2 and P2

Approximately 30 milliseconds

Physiological splitting of S2

More prominent during inspiration

Cause of S2 splitting

Increased venous return delays P2

Pitch of S1, S2 and opening snap

High pitched

High piched heart sound

(Heard by diaphragm)

• S1

• S2

• Opening snap

Stethoscope part for high pitched sounds

Diaphragm

Pitch of S3, S4 and murmurs

Low pitched

Low pitched heart sound include

Heard through bell

• S3

• S4

• Tumor plop sound (in cardiac tumor e.g atrial myxoma)

Stethoscope part for low pitched sounds

Bell

Tumor plop sound

Low pitched sound seen in atrial myxoma

Cause of tumor plop

Swinging tumor hitting mitral valve leaflet

Tumor causing plop sound

Atrial myxoma

Low pitch murmer

mid diastolic murmer

Is murmer heart sound?

no, it is due to turbulence of blood

Mid diastolic murmur heard with bell

Mitral stenosis

Cardiac auscultation areas

Five standard areas

Aortic area location

Right of sternum at 2nd intercostal space

Pulmonic area location

Left of sternum at 2nd intercostal space

Erb’s point location

Left of sternum at 3rd intercostal space

Best area to hear S2 splitting

Erb’s point

Tricuspid area location

Left of sternum at 4th intercostal space

Mitral area location

Left 5th intercostal space at midclavicular line

Nature of atrial myxoma

Pedunculated benign tumor

Site of atrial myxoma

Left atrium ( attached by stalk to wall)

Behavior of atrial myxoma

Swings like pendulum in atrial cavity

Effect of atrial myxoma on blood flow

Acts as obstacle to mitral inflow

Clinical feature of large atrial myxoma

Mid diastolic murmur mimicking mitral stenosis

Effort intolerance in atrial myxoma

Due to reduced LV filling

Sound mechanism in atrial myxoma

tumor obstacle →blood hit tumor →swinging of tumor →hit mitral valve leaflet → produce sound

Big sized atrial myxoma cause

mitral stenosis

Platypnea

Breathlessness on sitting relieved on lying down

Cause of platypnea in atrial myxoma

Tumor obstructs valve in upright position (gravity)

Clinical features of atrial myxoma

• young female

• Dyspnea on exertion

• Platypnea ( breathlessness while sitting → resolve on lying)

• Transient ischemic attacks ( embolism of platelet plug, embolism of tumor cell)

Cause of TIA in atrial myxoma

Tumor emboli or platelet emboli

Examination finding in atrial myxoma

• Pallor

• Tumor plop

• Mid-diastolic murmer

• Mitral regurgiattion ( damage to mitral leaflets )

Long term effect of atrial myxoma

Mitral regurgitation due to leaflet damage