Heart Sounds & Murmurs Flashcards
heart auscultation points
*AORTIC valve = right upper sternal border (2nd intercostal space)
*PULMONIC valve = left upper sternal border (2nd intercostal space)
*TRICUSPID valve = left lower sternal border (4th/5th intercostal space)
*MITRAL valve = left 5th intercostal space, midclavicular line
S1 heart sound
*“lub” sound
*represents closure of mitral and tricuspid valves (beginning of SYSTOLE)
*usually single, may be split
*best heard at apex and left lower sternal border
S2 heart sound
*“dub” sound
*represents closure of aortic and pulmonic valves (END of systole)
*often split
*best heard at base of heart (upper sternum)
systole/diastole relative to S1/S2
*systole = between S1 and S2
*diastole = after S2
S1 and S2 on Wigger’s Diagram
*recall: S1 = closure of atrioventricular valves (mitral/tricuspid); S2 = closure of semilunar valves (aortic/pulmonic)
S1 and S2 on pressure-volume loops
*recall: S1 = closure of atrioventricular valves (mitral/tricuspid); S2 = closure of semilunar valves (aortic/pulmonic)
split S2 heart sound
*S2 is divided into A2 and P2
*A2 = closure of the aortic valve
*P2 = closure of the pulmonic valve
*can have normal variation based on the respiratory cycle
respiratory cycle and heart sounds: inspiration
*inspiration → decreased thoracic pressure → increased venous return → increased blood in right ventricle → delay in closure of pulmonic valve (delay in P2)
respiratory cycle and heart sounds: expiration
*expiration → increased thoracic pressure → decreased venous return → less blood in right ventricle → P2 and A2 much closer together
normal physiologic splitting of S2
*INSPIRATION → decreased thoracic pressure → increased venous return → increased blood in right ventricle → delay in closure of pulmonic valve (delay in P2)
*inspiration can result in normal physiologic splitting of S2 heart sound, in which A2 sound occurs just before P2 sound
wide physiologic splitting of S2
*seen in conditions that delay RV emptying (RIGHT BUNDLE BRANCH BLOCK or PULMONIC STENOSIS)
*causes delayed pulmonic sound (delayed P2), especially on inspiration
*an exaggeration of normal splitting
fixed physiologic splitting of S2
*due to ATRIAL SEPTAL DEFECT (ASD)
*ASD → left-to-right shunt → increased RA and RV volumes → increased flow through pulmonic valve → delayed pulmonic valve closure
*does NOT vary with respiration
paradoxical splitting of S2
*heard in conditions that delay aortic valve closure (AORTIC STENOSIS or LEFT BUNDLE BRANCH BLOCK)
*due to delayed A2
*normal order of semilunar valve closure is REVERSED (in paradoxical splitting, P2 occurs before A2)
S3 heart sound
*rapid filling sound in early to mid diastole
*single, dull, and soft
*heard at apex or left lower sternal border
*caused by VOLUME OVERLOAD in heart failure
*comes after S2
*sounds like “Kentucky”
S4 heart sound
*atrial kick sound in late diastole
*single, dull, and soft
*heart at apex or left lower sternal border
*caused by stiff ventricle, such as caused by hypertension
*sounds like “Tennessee”
*comes immediately before S1
note - if atrial fibrillation present, you CANNOY have S4
effect of pressure on S4 & S3 gallop sounds
*light pressure: gallop sounds heard
*firm pressure: gallop sounds DISAPPEAR
*best to hear in left lateral decubitus position
summation gallops
*at slower heart rates, you may be able to appreciate both S3 and S4
*however, at higher heart rates, they may blur together - this is called a summation gallop
differentiating split S2 from S3/S4
*split S2 is heard at the upper sternal borders (right and left 2nd intercostal spaces)
*S3/S4 are better heard at the apex and left lower sternal border
*S3/S4 disappear with increased pressure; S2 does not
important factors to consider when auscultating for murmurs
*location of murmur
*grade of murmur
*onset and duration (midsystolic vs. holosystolic vs. late systolic)
*timing of peak intensity
*radiation of murmur
Levine Grading System for murmurs - 1/6
1/6 = murmur can only be heard if one listens carefully for some time
Levine Grading System for murmurs - 2/6
2/6 = murmur is faint but can be heard straight away with a stethoscope
Levine Grading System for murmurs - 3/6
3/6 = murmur is moderately loud and can be heard immediately but there is NO palpable thrill (vibration that can be felt)
Levine Grading System for murmurs - 4/6
4/6 = murmur is loud and accompanies a palpable thrill
Levine Grading System for murmurs - 5/6
5/6 = murmur accompanies a palpable thrill and is loud enough to be heard with just a slight touch of a stethoscope’s rim
Levine Grading System for murmurs - 6/6
6/6 = murmur accompanies a palpable thrill and is so loud that it can be heard before a stethoscope even makes contact with skin
mid-systolic murmurs
*“ejection murmurs”
*functional, benign, innocent, flow murmur
*aortic/pulmonic stenosis
*HOCM
*bicuspid aortic valve (ejection click in early-mid systole)
holosystolic murmur
*mitral/tricuspid regurgitation
*ventricular septal defect
late systolic murmur
*mitral valve prolapse with late mitral regurgitation
aortic stenosis murmur
*best heard at right upper sternal border
*does not start until the isovolumetric contraction period is completed
*the more severe the aortic stenosis, the later the peak of the murmur; represents force generated in order to open the valve
*can radiate up the carotids; can have a delayed carotid upstroke
*increases in intensity when LV ejects more blood
*Pulsus parvus et tardis: weak pulse & delay in relation to timing of murmur
hypertrophic obstructive cardiomyopathy murmur
*heard best at right upper sternal border
*does not start until the isovolumetric contraction period is completed
*tends to peak later in systole
*Pulsus bisferiens: double peaked pulse
*tends to get more intense with maneuvers which decrease LV size
pulmonic stenosis murmur
*systolic crescendo-decrescendo murmur heard best at the left upper sternal border
*starts at the end of isovolumetric contraction and stops at the beginning of isovolumetric relaxation; occurs when RV pressure > RA pressure
*the more severe, the later the peak
*INTENSIFIED WITH INSPIRATION and softens with expiration
mitral regurgitation murmur
*heard best at LV apex
*HOLOSYSTOLIC - occurs during both isovolumetric contraction & relaxation because LV pressure > LA pressure
*worsened by maneuvers which increase LV pressure because it increases the pressure difference between the LV and LA chambers
mitral valve prolapse murmur
*heard best at the LV apex
*often described as a MID-SYSTOLIC CLICK
*NOT holosystolic - it only starts after the mitral valve has been pushed back into the left atrium
*several maneuvers can cause the click to come earlier or later in systole (standing, squatting, etc)
tricuspid regurgitation murmur
*heard best at the left lower sternal border
*HOLOSYSTOLIC - occurs during both the isovolumetric contraction and relaxation because RV pressure > RA pressure
*worsened by inspiration and softens with expiration because of changes in volume in the right heart with the respiratory cycle
diastolic murmurs
- early diastolic murmur:
-aortic regurgitation
-pulmonary regurgitation - mid-diastolic murmur:
-mitral stenosis
-tricuspid stenosis - late diastolic murmur
-mitral stenosis
-tricuspid stenosis
aortic regurgitation murmur
*occurs in diastole, particularly early diastole
*can be heard in several locations: right upper sternal border & Erb’s point
*“Austin-Flint” murmur: if the jet hits the mitral valve, it can be heard at the apex
*the more severe the regurgitation, the shorter the murmur due to equalizing diastolic pressure between the aorta and LV
pulmonic regurgitation murmur
*occurs in diastole, particularly early diastole
*can be heard best in several locations: left upper sternal border & Erb’s Point
*the more severe the regurgitation, the shorter the murmur due to equalizing diastolic pressure between the pulmonary artery and RV
*murmur INCREASES IN INTENSITY WITH INSPIRATION due to increased flow to the right heart
mitral stenosis murmur
*occurs in diastole, particularly early diastole
*can be heard best at the LV apex, especially in left lateral decubitus position
*in many instances, the more severe the stenosis, the earlier will be the opening snap, which represents increased filling pressure, and the longer the murmur, represents continued gradient between LA and LV, even at end-diastole
murmurs that increase with inspiration
*right-sided only
*reflects increase in blood flow across the tricuspid and pulmonic valves because of increased venous return
murmurs that increase with expiration
*generally left-sided
*reflects decrease in lung that separates the heart from the chest wall
*there is no significant change in flow through the left-side of the heart with respiration - only in pathological states
maneuvers during auscultation that can change heart sounds
*valsava
*standing
*leg life
*squatting
*hand grip/pressors
*post-PVC beat
maneuvers that increase/decrease the HOCM murmur
*maneuvers which increase the space between the hypertrophied septum and mitral valve decrease HOCM murmur (and vice versa)
*VALSALVA & STANDING INCREASE HOCM murmur (decrease amount of blood coming back to the heart temporarily → LV size decreases → septum and mitral valve closer together)
*rapid squatting decreases HOCM murmur (increase venous return → increased blood coming back to heart → increase LV size → septum and mitral valve farther apart)
using maneuvers to differentiate aortic stenosis vs. HOCM on auscultation
*valsava/standing (decrease amount of blood coming back to the heart temporarily → LV size decreases → septum and mitral valve closer together)
-INCREASES HOCM murmur
-DECREASES aortic stenosis murmur
*rapid squatting (increase venous return → increased blood coming back to heart → increase LV size → septum and mitral valve farther apart)
-DECREASES HOCM murmur
-INCREASES aortic stenosis murmur
maneuvers that increase/decrease mitral valve prolapse murmur
*maneuvers that increase LV size put more tension on chordae → prevents mitral valve from going back into LA until later in systole
*standing → decreased venous return to heart → LV size small → less tension on chordae tendonae → mid-systolic click will occur sooner
*squatting → increased venous return → stretch on LV → mid-systolic click will occur later
effect of valsalva & standing maneuvers on murmurs
*simply put, valsalva decreases preload, which decreases stroke volume and LV size
*valsalva and/or standing → decreased venous return → decreased LV size & decreased stroke volume:
-aortic stenosis murmur: decreased
-HOCM murmur: increased
-mitral valve prolapse: earlier mid-systolic click
effect of squatting maneuver on murmurs
*simply put, squatting increases preload, which increases stroke volume and LV size; also increases afterload
*squatting → isometric leg muscle contraction → increased venous return → increased stroke volume & increased LV size:
-aortic stenosis murmur: increased
-HOCM murmur: decreased
-mitral valve prolapse: later mid-systolic click
effects of leg lift maneuver on murmurs
*simply put, leg life increases preload by returning volume to the heart and central cavity
*leg lift → increased venous return → increased stroke volume & increased LV size:
-aortic stenosis murmur: increased
-HOCM murmur: decreased
-mitral valve prolapse: later mid-systolic click
effects of hand grip/pressors maneuvers on murmurs
*simply put, hand grip/pressors serve to increase afterload
*hand grip/pressors → increased aortic pressure → decreased stroke volume, increased LV size, and increased LV pressure:
-aortic stenosis murmur: decreased
-HOCM murmur: decreased
-mitral valve prolapse: later mid-systolic click
-aortic/mitral regurgitation murmur: increased
-VSD: increased
the post-PVC beat: Brockenbrough sign
*the post-PVC beat occurs after the compensatory pause associated with the PVC
*diastolic BP decreases during compensatory pause (decreased afterload)
*LV EDP increases during compensatory pause (increased preload)
*increased contractility
*result: intensity of the murmur increases for aortic stenosis, HOCM, and pulmonic stenosis
