Heart Sounds Basics

By the end of this course, you should be able to:    Identify the requirements for assessing heart sounds adequately.      List the characteristics of heart sounds.     Differentiate between normal heart sounds and murmurs.      Vibrations from the heart’s structures (valves) that can be heard and differentiated by a stethoscope (auscultation) NOTE: throughout this course, a condition name or other information in bold red font means there is a link to a sample of the sound associated with the term. Heart sounds are referred to as S1 S2 S3 S4 Abnormal heart sounds are referred to as Murmurs Clicks Snaps   The sudden acceleration/deceleration of blood flow The tensing of the valves and myocardium actual closure of valve leaflets is not heard vibrations due to tensing are heard ABNORMAL: hearing valves open   Intensity (loudness): influenced by size of individual location Location: where the heart sound is heard best Respiratory Variance: splitting or merging Radiation: confirms the sound's transmittal to neck/axilla Frequency (pitch): number of vibrations per sound Duration: length of time  Quality: descriptive sound Timing: when the sounds occur Shape: increase or decrease in sound intensity Grade 1: faint, hard to hear Grade 2: medium intensity Grade 3: moderately loud; clearly audible Grade 4: loud Grade 5: loud enough to be heard with stethoscope only partially on chest wall Grade 6: audible with stethoscope near, but not touching the chest wall THRILL: palpable vibration felt with hand on chest wall (usually denotes stenosis) Respiratory Variance: right-sided heart sound increase with inspiration Systole Diastole Early Mid Late Holo/Pan   The shape of a murmur describes the change of intensity throughout the cardiac cycle. Murmur types Crescendo: building in intensity Decrescendo: diminishing in intensity Crescendo – Decrescendo: build up–peak– diminish Uniform Shape - intensity over time   Dependencies Distance between the leaflet tips of the MV and TV at the onset of systole Mobility of leaflets (stiffness) How fast pressure rises in the ventricles Increased Intensity Short PRI: sound becomes accentuated when valve leaflets are too far apart and forced shut from a relatively wide distance Mild MS: stiffened leaflets cannot drift together and are forced to shut loudly when LV contracts Tachycardia: shortened diastole forces MV and TV leaflets together from a wider apart position – they have not had sufficient time to drift back together Decreased Intensity 1st degree AVB: delays onset of systole. Allows MV, TV leaflets sufficient time to drift back together from a relatively short distance apart MR: with moderate to severe MR, MV leaflets never fully close decreasing the audibility of S1 Stiffened LV: Hypertrophy/systemic HTN can increase pressure in LV, forcing early closure of MV leaflet which are already fairly close together Dependencies Blood flow velocity back toward semilunar valves from the aorta and PA after ventricular systole How quickly and suddenly that flow is arrested with valve closure Increased Intensity Occurs with either systemic or pulmonary artery HTN Diastolic pressures are elevated velocity of blood flow is increased S2 becomes louder Decreased Intensity Occurs with severe AS or PS Valve leaflets are rigid/fixed in position and de-accentuate the S2 sound Heartbeat cadence usually distinguishes S1 from S2 Diastole takes about twice as long as systole Pause between S2 and S1 is longer than between S1 and S2 Left sided events precede right sided events LV flow starts first/ends last MV closes – TV closes – PV opens – AoV opens SA node fires LV contraction begins first with closure of the MV Right heart lags ever so slightly due to anatomy of the conduction system TV valve closes Pulmonary arterial pressure is low Aortic pressure is high It takes longer for the LV pressure to build high enough to force open the AoV so the PV opens first Again, due to higher Ao pressure than PA pressure, the AoV closes first PV closes (look for dicrotic notch to indicate semilunar closure) The pressure during systole in the LV is much greater than in the RV You can predict that the MV closes before the TV in S1 LV flow starts first/ends last MV closes – TV closes – PV opens – AoV opens   1. Aortic 2. Pulmonic 3. Erb's Point 4. Tricuspid 5. Mitral/Apical Eliminate or decrease environmental noise Concentrate as you listen for each sound Avoid auscultating through clothes Keep stethoscope tubing off surfaces Ask the patient to breathe normally S3 and S4 sounds may merge with an increased heart rate Learn more: Select the name of each gallop to hear an audio clip of it.     Summation Gallop: three distinct heart sounds Quadruple Gallop:  all four heart sounds are audible Sound files: MedEdu, LLC Soft blowing, rasping, or rumbling sound heard on auscultation Origin: vibrations produced by the turbulent flow of blood within the heart and great vessels  Further categorized as systolic or diastolic Systolic murmur: most common Functional or innocent murmurs are common in children or young adults Usually disappears when patient sits upright Sample sound: Innocent heart murmur Sound file: teachingheartauscultation.com Increased rates of flow over normal or abnormal valves Stenosis: Forward flow through constricted or deformed valve Dilated Cardiomyopathy/Aortic Aneurysm: Forward flow of blood into a dilated chamber or vessel Regurgitation: Backward flow of blood through an incompetent valve Ventricular Septal Defect (VSD): Abnormal shunting of blood from a higher pressure chamber to a lower pressure chamber Aortic Stenosis: impaired blood flow through calcified or deformed (bicuspid) AoV Causes increased pumping pressure in the LV Listen for ejection murmur or ejection click High pitched – use diaphragm Auscultate at aortic area 2ICS, RSB Severe AS sound radiates to neck & apex Pulmonic Stenosis: impaired blood flow over calcified or deformed PV Causes increased pumping pressure in the RV Listen for ejection click Best heard at pulmonic area 2ICS, LSB May radiate to left shoulder and neck Sound files: teachingheartauscultation.com Image courtesy of Siemens Healthineers HQ        Aortic Stenosis Doppler Waveform Origin The sound that marks the approximate beginning of ventricular systole. Is created when the increase in intraventricular pressure during contraction exceeds the pressure within the atria causing a sudden closing of the AV valves. The S1 Heart Sound Lub: the way the sound is described Is a high frequency sound best heard with the diaphragm of the stethoscope auscultated over the tricuspid and mitral areas. On an ECG it is represented by the QRS or onset of ventricular Systole. The timing occurs during isovolumic contraction time.          Image and sound file: University of Nebraska Medical Center . Origin At the end of systole when the ventricles begin to relax The pressures within the heart become less than the pressures in the aorta and PA A brief backflow of blood causes the semilunar valves to shut The S2 Heart Sound Dub: the way the sound is described Closure of the semilunar valves (AoV closes slightly before PV) Isovolumic Relaxation Time (IVRT) Opening of AV valves Increased frequency and shorter duration than S1 Can be seend on ECG at T wave or onset of ventricular diastole Best heard at the aortic area (2ICS, RSB) or Erb’s Point (3ICS, LSB) High frequency: use diaphragm Varies with respirations: fused as one sound with expiration – are audibly separate during inspiration. This is called a normal or “physiologic splitting” Split S2 is best heard at the pulmonic area               Image and sound file: University of Nebraska Medical Center Etiology Follows S2 in early ventricular diastole Probably results from vibrations caused by abrupt ventricular distention and resistance to filling Normal sound for children and young adults Abnormal in adults over the age of 30 Diastole: divided into phases Passive filling Rapid filling Last 30% ejected with "atrial kick" Sound Specifics Left-sided heart sound May indicate CHF, anemia, or dilated cardiomyopathy (dilated LV due to over-distension secondary to over-filling)  Present with MR with increased atrial volume increases ventricular volume Heard with pericarditis and arterial HTN Ventricular gallop sound Cadence: “Ken-TUC-ky” Occurs in early – mid ventricular diastole (after T wave) Best heard at apex Low pitched Use bell           Image and sound file: University of Nebraska Medical Center   Late Stage of Diastole Marked by atrial kick Final blood volume forcefully ejected into the ventricles Stiffened and noncompliant ventricle (as in ventricular hypertrophy): increased pressure present in the atria can produce an S4 Atrial Gallop S4 sound, or atrial gallop, indicates increased resistance to ventricular filling Results from vibrations caused by forceful atrial ejection of blood into ventricles that don’t move or expand efficiently Heard over the tricuspid or mitral area when patient lies on left side Occurs just before S1 after atrial contraction                 Sound Specifics May be present in healthy adults, but is usually ABNORMAL Likely left-sided heart sound cause: stiffened, non-compliant ventricular muscle due to HTN, MI, CAD, or aortic stenosis Cadence: “Ten – nes – see” Best heard at apex dull use bell      Image and sound file: University of Nebraska Medical Center   Mitral Regurgitation: retrograde blood flow over incompetent MV into LA during systole Heard throughout systole with no interval between S1 and S2 Best heard with diaphragm at apex or mitral area Has a high-pitched blowing sound that often radiates to L axilla Tricuspid Regurgitation: retrograde blood flow over incompetent TV into RA during systole Heard throughout systole Best heard at tricuspid area  radiates to R sternum High pitched blowing sound that increases in intensity with inspiration Select the popup screens below to see samples of mitral and tricuspid regurgitations. Sound files: easyauscultation.com   Mitral Regurgitations MItral Regurgitations     Eccentric Mitral Regurgitation 3D Color Doppler of Mitral Regurgitation on TEE Mitral Regurgitation Doppler waveform on TEE Image files: 1 - Mitral regurgitation: drsvenkatesan.com/tag/eccentric-mitral-regurgitation/  2 and 3 - Courtesy of Siemens Healthineers HQ     Tricuspid Regurgitations Tricuspid Regurgitations       3D PISA Analysis of Tricuspid Regurgitation   Severe Tricuspid Regurgitation Image files: 1 - Courtesy of Siemens Healthineers HQ 2 - Tricuspic regurgitation: merckmanuals.com   Mitral Valve Prolapse Alternative names: Barlow’s syndrome, floppy-valve syndrome, or billowing mitral valve syndrome Bowing of valve leaflets into the LA during ventricular systole May be associated with MR Listen for a mid-systolic click              Aortic Insufficiency: retrograde flow of blood over incompetent AoV into LV during diastole High pitched crescendo – decrescendo murmur Best heard at onset of diastole Patient: sitting up, leaning forward, and exhaling Auscultate at aortic area; sound may radiate to neck Pulmonic Insufficiency: retrograde flow of blood over incompetent PV into RV in diastole Crescendo – decrescendo murmur that is enhanced with inspiration Best heard at 2 ICS, LSB Probably secondary to pulmonary arterial HTN To see examples of these insufficiencies, click the popup at the bottom of the screen. Sound files: easyauscultation.com Aortic & Pulmonic Insufficiencies Aortic & Pulmonic Insufficiencies         Aortic Insufficiency Pulmonic Insufficiency Mitral Stenosis: forward turbulent flow of blood from LA into LV through thickened, stenosed MV during diastole Often results from childhood rheumatic fever Low rumbling murmur is usually loudest at late diastole during atrial kick with accelerated flow of blood over MV Listen for opening snap earlier in diastole Best heard at mitral area Select the popup icon at the bottom of the screen to see an animation of mitral stenosis.              Severe MR due to rheumatic MV disease Mitral Stenosis Animation Mitral Stenosis Animation              Mitral stenosis animation by Steven Farmer, DO, University of Hawaii, Maui College Tricuspid Stenosis: forward turbulent flow of blood over thickened TV from RA to RV in diastole Listen for opening snap Best heard at tricuspid area Often undetected because it is usually associated with MS Pericardial Friction Rub: high-pitched, scratchy murmur associated with inflammation of the pericardial sac Often post MI            Pericardial Friction Rub Papillary Muscle Rupture:  may produce a loud clicking sound in mid-systole     Papillary Muscle Rupture Ventricular Aneurysm: muffled gallop rhythms heard in both systole and diastole Select the popup at the bottom of the screen to see an animated diagram of a ventricular aneurysm. Ventricular Septal Defects (VSD): holosystolic murmur due to turbulent flow of blood from a high pressure LV to a low pressure RV through a hole in the septum. May be associated with a palpable "thrill” Does not increase in intensity with inspiration Does not radiate The smaller the hole, the louder the murmur: sometimes classified as "the loudest of all murmurs"          Ventricular Aneurysm Animation Ventricular Aneurysm Animation   Animation produced by: Deep Animation Now that you have completed this course, you should be able to:   Identify the requirements for assessing heart sounds adequately.    List the characteristics of heart sounds.    Differentiate between normal heart sounds and murmurs. Earpieces or earbuds Binaurals   Connect the two earpieces   Should be gently bent for proper fit Tubing   As short as possible (12’’ – 15’’) to reduce the distance that sound must travel Bell Diaphragm        Bell – at least 1’’ in diameter Used to hear low-pitched sounds Held lightly against chest Diaphragm – at least 1 ½’’ in diameter Used to hear high frequency sounds Held firmly against the chest Stethoscope diaphragm/bell positioning   Auscultate to where the sound radiates Do not auscultate over the anatomical location of the valve Patient position Lying Sitting Left lateral decubitus Heart Sounds Basics This course is designed to provide you with an overview of heart sounds, their classifications, and their significance in treating heart conditions of various types. After completing this course, you will be able to understand the sounds of the heart and what those sounds mean.