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Heart Sounds and Murmurs

J.B. Handler, M.D.Physician Assistant ProgramUniversity of New England

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Abbreviations A- aortic P- pulmonic T- tricuspid M- mitral AV- atrioventricular SL- semi-lunar SB- sternal border ASD- atrial septal defect AR- aortic regurgitation AS- aortic stenosis TR- tricuspid regurgitation PVR- peripheral vascular

resistance IO- interest only CHD- coronary heart disease

MR- mitral regurgitation MS- mitral stenosis SEM- systolic ejection murmur MVP- mitral valve prolapse LBBB- left bundle branch block ICS- intercostal space RV- right ventricle LV- left ventricle LA- left atrium RA- right atrium PS- pulmonic stenosis PR- pulmonic regurgitation LLD-left lateral decubitus

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Listening Points/Positions Aortic: “base”- 2nd Rt ICS, SB Pulmonic: “base”- 2nd Lt ICS, SB 3rd Lt ICS, SB Tricuspid: lower Lt sternal border(4-5ICS) Mitral: cardiac apex (LV) 5ICS, MCL Sitting, lying, left lateral decubitus (s3,4

gallops, and mitral stenosis)Internet sites for heart sounds: http://www.cardiologysite.com http://www.blaufuss.org/

Auscultation Areas

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Heart Sounds S1- mitral/tricuspid valve closure. S2- aortic/pulmonic valve closure. Distinguishing S1 vs S2

-Listen at apex, palpate carotid-S1 precedes carotid pulse.

-Intensity of S1>S2 at apex (reverse at base).

-S1 immediately precedes the PMI. S1 occasionally splits with inspiration (.02-.03 seconds)…difficult to

hearMV closes before TV, accentuated with inspiration.

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S2 Splitting Commonly heard in inspiration (separation of

A2 and P2 is .02-06 Sec). A2 normally precedes P2- accentuated in

inspiration because RV volume increases, LV volume decreases………..why?

Fixed splitting: ASD. Paradoxical splitting: Aortic valve closure is

delayed, closes after pulmonic. P2 precedes A2 . During inspiration they move

together, in expiration they move apart. Examples: Aortic Stenosis, LBBB.

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Splitting of 2nd Heart Sound

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3rd Heart Sound vs S3 Gallop 3rd heart sound: Low pitched sound, .1-.2 sec post

S2. May be heard in young, healthy people. Reflects rapid inflow of blood into normal, compliant LV.

S3 gallop: abnormal “dull thud” in mid diastole. LV dysfunction and dilation often present (CHF). Also heard with MR, AR with volume overload.

Pathophys: 1. Sudden deceleration of blood flow into diseased, dilated & non compliant ventricle. 2. AR/MR- volume overload with rapid inflow of increased blood volume into compliant LV.

Best heard: bell at apex in LLD position. Timing: lub….du..dub

S1 S2 S3

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S4 Gallop Almost always abnormal Short, low frequency, precedes S1

“presystolic gallop”. Pathophys: Atrial contraction into non-

compliant ventricle. Conditions: LVH (HTN, AS), CHD (ischemia

or infarction). Best heard: bell at apex in LLD position. Timing: bu.lub….dub

S4 S1 S2

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Murmurs: Grading Scale Grade I- Very faint; barely audible. Often

heard only by experienced clinicians. Grade II- soft, but audible Grade III- moderately loud Grade IV- loud with associated thrill Grade V- very loud + thrill; audible with

diaphragm on end. Grade VI- very loud + thrill; audible with

stethoscope off chest.

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Murmurs: Radiation Depends on direction of blood flow

responsible for the murmur, duration of and intensity of the murmur.

Aortic outflow murmurs (AS) radiate from the cardiac base/aortic area to base of neck or carotids.

Most MR murmurs radiate to axilla. AR murmurs radiate down LSB

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Murmurs: Description Intensity: see grading scale Quality: Blowing, harsh, grating, rumble. Pitch: High vs low pitched Timing: Early/mid/late systolic vs.

holosystolic. Early/mid diastolic. Configuration: Crescendo-decrescendo,

decrescendo, plateau, others.

Murmur Timing and Configurations

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Murmurs: Use of Maneuvers Respiration: Inspiration RV filling/volume.

Murmurs arising from Rt side of heart (PS, PR, TR) get louder during inspiration and reverse in expiration.

Valsalva: Net effect is venous return to RV; RV followed by LV volume.

Squatting: venous return to heart; PVR and BP. Net effect: LV and RV volumes.

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Murmurs: Use of Maneuvers Rapid upright posture after squatting:

venous return to RV, PVR. Net effect:RV and LV volumes.

Isometric exercise (handgrip):PVR and BP, CO/HR. Net effect- makes murmurs of MR and AR louder. Avoid in patients with myocardial ischemia and ventricular arrhythmias.

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Murmurs: Maneuvers Outflow murmurs across aortic and pulmonic

valves (includes AS, PS and innocent murmurs) get louder with maneuvers that LV/RV volume and softer with LV/RV volume.

Insufficiency Murmurs: AR, MR, TR act similarly to above.

Exceptions: Murmur of MV prolapse and hypertrophic cardiomyopathy get louder with maneuvers that LV volume and softer with reverse physiology.

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Characteristic Systolic Murmurs Innocent or functional murmurs: arise from

pulmonic or aortic outflow tracts in the presence of normal pulmonic/aortic valves. Common in young, healthy individuals. Usually Grade I or II, get louder with squatting and very soft or absent with standing/valsalva. Mid-systolic, short.

Aortic stenosis: harsh, often loud, best heard base/aortic area, C/D (crescendo/decrescendo), radiate to neck/carotids. Length of murmur correlates with severity of obstruction. Best heard with diaphragm.

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Characteristic Systolic Murmurs Mitral regurgitation: high pitched, blowing,

best heard at apex, holosystolic (if not acute), radiates to axilla. Best heard with diaphragm.

MV prolapse with MR: high pitched, blowing, best heard at apex, mid to late systolic and often preceded by valve click. Characteristic changes with maneuvers (see above). Best heard with diaphragm.

Pulmonic stenosis (congenital defect): harsh, best heard at base/pulmonic area, C/D radiates down LSB. Louder in inspiration.

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Characteristic Diastolic Murmurs Aortic regurgitation/insufficiency:

high pitched, blowing, best heard along LSB, 2nd/3rd ICS, decreshendo, begins with S2, radiates down LSB. Best heard with diaphragm.

Mitral stenosis: low pitched, rumbling, best heard at apex, mid diastolic. Best heard with bell- easily missed with diaphragm.