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First Heart Sound (S1) Produced by closure of mitral valve and tricuspid valve in early systole

Best heard at the apex of the heart. High frequency diaphragm

Actually the mitral valve closes before tricuspid valve, separated by only 0,01s heard as a single sound

3 factors determine the intensity of S1:1) The distance separating the leaflets of the open valves at the onset of

ventricular contractiondescribed by PR interval in the ECG periodbetween onset of atrial and ventricular contraction. When atrial contractionoccurs, the valve will open. As the ventricle contracts, the leaflets are driftedback together and forced to shut

2) Mobility of the leaflets3) The rate of ventricular pressure

Accentuated S1short PR intervalvalve leaflets dont have sufficient time todrift back togetherforced to shut from relatively wide distance. Examples: mildstenosis, tachycardia

Reduced intensity of S1first degree AV blockdelays of the ventricularcontractionvalves have additional time to float back together softer sound

Second Heart Sound (S2)

Results from the closure of aortic and pulmonic valves has aortic (A2) andpulmonic (P2) components

The components of S2vary with the respiratory cyclefused during expiration andseparated during inspirationphysiologic splitting

At inspirationmore negative intrathoracic pressure capacitance ofintrathoracic pulmonary vesselstemporary delay in diastolic back pressure of the

pulmonary artery for the closure of pulmonary valvedelayed P2 Inspirationmore negative intrathoracic pressure capacitance of pulmonary

vein venous return to LA and LV SVshortens valve closure

Intensity of S2depends on the velocity of blood coursing back toward the valves fromaorta and pulmonary artery and the suddenness with which that motion is arrested bythe closing of the valves

Hypertensionaccentuated S2because the pressure is each great artery is higher blood velocity

Severe aortic or pulmonary valve stenosisvalve commissures are nearly fixed in positiondiminished S2

There are 3 types of abnormal splitting of S2:

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Extra Systolic Heart Sounds Early Extra Systolic Heart Sounds (Ejection Clicks)

Occurs shortly after S1coincide with the opening of the aortic or pulmonic valves Sharp, high pitched, best heard with diaphragm placed over the aortic and pulmonic areas

Aortic and pulmonic stenosisdeformed valve leaflets reach their maximal level of ascent into the great artery before the bloodejectionreach their elastic limits decelerate abruptlyejection click

Dilatation of the root of the aorta or pulmonary artery sudden tensing of the root with onset of blood flow into vessel ejection click

Aortic ejection click: heard both at the base and apex of the heart, doesnt vary during respiration

Pulmonic ejection click: heard only at base, intensity diminishes during inspiration

Mid or Late Extra Systolic Heart Sounds

Result of systolic prolapsed of the mitral or tricuspid valves leaflets bulge abnormally into the atrium

Loudest over the mitral or tricuspid regions

Extra Diastolic Heart Sounds

Opening Snap Resulting from the opening of mitral and tricuspid valves

Sharp, high-pitched, timing doesnt vary with respiration

In mitral stenosisheard best between the apex and left sterna border, just after A 2

Can be confused with P2. With careful auscultation, 3 sounds occurring in rapid successions A2, P2, OS Third Heart Sound (S3)

Occurs in early diastole, following the opening of AV valves, during the ventricular rapid filling phase

Dull, low-pitched, best heard with bell

Production of S3results from tensing of the chordae tendinae during rapid filling and expansion of the ventricle

Normally found in children and young adults, abnormal in middle-aged or older adults

When abnormally heardvolume overload because CHF/ transvalvular flow that accompany advanced mitral/tricuspid regurgitation

Pathologic S3ventricular gallop Fourth Heart Sound

Occurs in late diastole, coincides with the contraction of atria Generated by the left or right atrium vigorously contracting against a stiffened ventricle

Thus, the presence of S4usually indicates a in ventricular complianceventricular hypertrophy or myocardial ischemia

Dull, low-pitched sound, best heard with bell

Also known as atrial gallop Quadruple Rhythm or Summation Gallop

Patients with S3and S4, in conjunction with S1and S2produce quadruple beat

If patient with quadruple rhythm develops tachycardia shorter diastole durationS3and S4coalescesummation gallop Pericardial Knock

Uncommon, high-pitched

Hallmark of constrictive pericarditis

Appears early in diastole, soon after S2, later than OS, louder and earlier than ventricular gallop

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Results from abrupt cessation of ventricular filling in early diastole