Heart Sounds and Murmurs

1. Heart Sounds and Murmurs J.B. Handler, M.D. Physician Assistant Program University of New England

2. 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 Abbreviations

3. 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/

4. Auscultation Areas

5. 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 hearMV closes before TV, accentuated with inspiration.

6. 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. IO

7. Splitting of 2nd Heart Sound

8. 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

9. 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

10. 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.

11. 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

12. 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.

13. Murmur Timing and Configurations

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.