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Home , Auscultation, Cardiac examination, Heart sounds, Pulse

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Crit Care Nurs Q Vol. 30, No. 2, pp. 166–180 Copyright c 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins Practical Cardiac

Daniel M. Shindler, MD, FACC

This article focuses on the practical use of the . The art of the cardiac physical exam- ination includes skillful auscultation. The article provides the author’s personal approach to the patient for the purpose of best hearing, recognizing, and interpreting sounds and murmurs. It should be used as a brief introduction to the art of auscultation. This article also attempts to illustrate and murmurs by using words and letters to phonate the sounds, and by presenting practical clinical examples where auscultation clearly influences cardiac diagnosis and treatment. The clinical sections attempt to go beyond what is available in standard textbooks by providing information and stethoscope techniques that are valuable and useful at the bedside. Key words: auscultation, murmur, stethoscope

HIS article focuses on the practical use mastered at the bedside. This article also at- T of the stethoscope. The art of the cardiac tempts to illustrate heart sounds and mur- includes skillful auscul- murs by using words and letters to phonate tation. Even in an era of advanced easily avail- the sounds, and by presenting practical clin- able technological bedside diagnostic tech- ical examples where auscultation clearly in- niques such as , there is still fluences cardiac diagnosis and treatment. We an important role for the hands-on approach begin by discussing proper stethoscope selec- to the patient for the purpose of evaluat- tion and use. ing and reassessing cardiac status. Knowing the cardiac history, monitoring the and CHOOSING A STETHOSCOPE pressure, and listening to the heart and are integral parts of nursing care. Proper It has been stated that proper auscultation use of the stethoscope is still relevant and im- of the heart depends less on what is around portant to patient care. This article provides the ears and more on what is between the the author’s personal approach to the patient ears. Nevertheless, there are certain easily for the purpose of best hearing, recognizing, recognized features that make a stethoscope and interpreting heart sounds and murmurs. It more capable of transmitting heart sounds to should be used as a brief introduction to the the ears. art of auscultation. Although there are many The cardiac stethoscope requires both a excellent audiovisual aids to auscultation, the bell and a diaphragm to transmit the full spec- should be honed and trum of heart sounds. The difference between the two is that the bell allows low-frequency sounds. The diaphragm filters those out when necessary. Both are used as needed to al- From the Departments of and low detection of all auditory aspects of heart Anesthesiology, UMDNJ Robert Wood Johnson sounds and murmurs. Medical School. There are cardiac that do not This article was prepared with the financial support have a bell. The bell effect is created by light of 3M. pressure on a specially designed stethoscope Corresponding author: Daniel M. Shindler, MD, FACC, diaphragm. When the stethoscope was first UMDNJ Robert Wood Johnson Medical School, 125 Pa- terson St, New Brunswick, New Jersey 08901 (e-mail: invented, there was no diaphragm, just a bell. [email protected]). The diaphragm effect could still be created 166 LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

Practical Cardiac Auscultation 167

Figure 1. 3M Littmann Electronic Stethoscope Model 3000 with ambient noise reduction.

by firm pressure on the skin to stretch it, re- justment of this angle to permit forward tilt- sulting in a makeshift temporary diaphragm. ing to align with the external ear canal and We still use this bell-push technique in every to create a complete seal that excludes am- patient. Examples for using the bell and the bient noise. A good habit to try to optimize diaphragm appropriately are presented in sub- this angle at the onset of auscultation con- sequent sections. sists of moving the head up and down in an Electronic stethoscopes can change filter exploratory manner while listening for im- frequency settings to toggle between bell proved audibility of heart sounds. Carrying a and diaphragm modes. New electronic stetho- stethoscope around by stuffing it into a labo- scopes with ambient noise reduction such as ratory coat pocket may change and misalign the Littmann Model 3000 (Fig 1) reduce dis- this critical angle. tracting ambient noise through noise cancel- Earpieces should feel comfortable. The fit lation rather than just filtering, so the heart should be snug without causing discomfort sounds remain unaffected and can actually be when used for prolonged periods of time. An selectively amplified. earpiece can be too large, allowing ambient Tubing should be kept comfortably short noise to enter. It can also be too small, too soft, (to better hear high-pitched heart sound com- or applied with too great a pressure—making ponents). The tubing should remain long it rest too deeply in the ear canal, with the enough to allow a comfortable listening pos- earpiece aperture partly or even completely ture. This is determined to some degree by the occluded. A common mistake is to choose ear- listener’s height, arm length, ability to bend pieces that are too small and enter too far. The the lower back, and degree of personal will- ear canal should be occluded, not invaded. ingness to lean over patients from the right Larger, looser-fitting earpieces can be made to side. fit more snugly during auscultation, if needed, Because of the of the ear canal, the by pressing the arms of the stethoscope to- angle of direction of earpieces is very impor- gether with the free hand. Listening from the tant. The external ear canal travels toward the right side of the patient keeps the stethoscope eardrum at an anterior angle. A good stetho- in a relatively straight line from the ears to the scope has angled earpieces to allow easy ad- chest. LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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PROPER CARE AND CLEANING OF interfere significantly with auscultation. Faint STETHOSCOPES sounds are masked by louder sounds. The loud sound does not even have to coincide The stethoscope is a medical tool. As such, with the faint sound. The ear instinctively it should be kept clean and regularly disin- tunes to the louder sound and ignores the fected to prevent spreading infection from pa- fainter sound. Proper auscultation technique tient to patient. Earpieces should be periodi- requires listening to one thing at a time. Faint cally inspected for cracks and for earwax ac- sounds require concentration. They should be cumulation. Tubing should also be visually in- listened to (without loud distractors) for as spected for cracks on a routine basis. Leaks in long as necessary. This allows the ear to be- the tubing due to cracks can also be detected come attuned to the full intensity of that par- by blowing into one earpiece while the other ticular sound level. Sometimes it also helps is obstructed. The absence of leaks can be fur- to close one’s eyes. Auscultation cannot be ther sought by abruptly breaking the seal of a hurried examination. The period of time the stethoscope bell with the skin during rou- necessary for proper examination will (hope- tine auscultation. Rapid removal of the bell fully) progressively decrease with experience. should elicit a pressure sensation in the ear Electronic stethoscopes with ambient noise when the tubing is intact. reduction are also available. They may dramat- ically improve the diagnostic yield of an aus- EXAMPLES OF BELL AND cultatory examination in a noisy environment DIAPHRAGM USE such as a moving ambulance, or a busy emer- gency department. As a rule, the bell is held lightly, and the diaphragm is pressed firmly against the skin EXAMINATION TECHNIQUE of the chest wall. The examiner should be- come adept at applying the stethoscope bell The patient is usually approached from the with as little pressure as possible. The pres- right side and the cardiac examination always sure should be no more than what is required begins with proper positioning of the patient. to create a seal to exclude ambient noise. This The patient should be positioned, and the ex- enhances the faint low-frequency vibrations amination bed or table should be adjusted to from ventricular and atrial gallops. As already allow sequential examination of the patient in mentioned, firm pressure with the bell makes the sitting, recumbent, and left lateral decu- the stethoscope behave like a diaphragm by bitus positions. Sitting positions include up- stretching the skin and making it filter heart right, reclining back at an approximately 45 sounds in the way a rigid diaphragm does— degree angle, and any other angle that opti- by damping vibrations. The high-pitched mur- mizes inspection. Additional patient murs of aortic regurgitation and some cases positions during advanced dynamic ausculta- of mitral regurgitation are better heard with tion may include standing and squatting, face the use of the diaphragm to filter out the down on the bed, and leaning forward while low-frequency components of other distract- standing or sitting. Both the examiner and the ing heart sounds. The diaphragm is pressed patient must be comfortable. Room temper- very firmly against the skin for this purpose. ature should be appropriate for the patient’s state of dress. The patient should be properly AMBIENT NOISE gowned so that the skin of the chest wall can be reached by the examiner without having to The room should be made as quiet as possi- fumble with the patient’s clothing. Proper aus- ble. Ambient noise must be minimized. High cultation should not be done through cloth- ambient noise levels and intermittent loud ing. The stethoscope should be applied di- sounds from speech or electronic equipment rectly on the skin. Lighting should be available LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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to cast tangential shadows on the skin of the The radial should not be used to time right side of the neck so that internal and ex- the during auscultation because ternal jugular can be inspected while si- there is a delay before the pulse arrives at the multaneously listening to the heart. . In the intensive care unit, elec- trocardiographic monitoring equipment may INSPECTION OF THE NECK VEINS be set to sound a beep to mark the QRS of the patient. This beep is also a marker of Inspection of the patient should precede and should be audible simultaneously with auscultation since there are many visual clues the carotid upstroke. to the presence, extent, and nature of heart The normal carotid pulse is felt in systole, disease. Once auscultation begins, it may be after the first heart sound is heard, and before useful to close the eyes temporarily to im- the second heart sound is heard. A weak and prove auditory concentration. During the rest delayed (parvus-et-tardus) pulse is palpated in of the time the eyes should be trained on the patients with aortic . There may also right side of the neck where the jugular ve- be a palpable shudder (called a thrill) in the nous pulsations are best seen. pulse of these patients. A bounding pulse is Inspection of the jugular venous pulsations felt in , aortic regurgitation, or helps in the timing of heart sounds and patent ductus arteriosus. A 2-component sys- murmurs. In the normal patient the most tolic pulse is called a bisferiens pulse. prominent jugular venous upstroke is the A wave. The A wave is produced by right INTEGRATING AUSCULTATION WITH atrial contraction and becomes visible just INSPECTION AND before the first heart sound is heard with the stethoscope. A triple-sensory (not for the southpaw) ap- Venous neck pulsations must be differenti- proach to the patient consists of visual infor- ated from arterial pulsations. Venous mation from the neck, auditory information are weak, not palpable. Venous pulses are from the stethoscope, and tactile (palpation) obliterated by pressure at the base of the neck, input from the free hand which is not holding altered by changes in body position, and af- the stethoscope. To place the stethoscope on fected by respiration and by pressure on the the chest at the point of maximal impulse, one abdomen (hepatojugular reflux). would find the impulse with the right hand, hold the stethoscope with the left hand, and PALPATION OF THE CAROTID place it directly over the impulse felt with the UPSTROKE right hand. Once the stethoscope is properly positioned with the left hand over the palpat- The carotid upstroke should be used to time ing right hand—it is possible to change the systole and to characterize the pulse as nor- stethoscope from left hand to right hand. The mal, weak and delayed, bounding, shudder- right hand can then vary the pressure exerted ing, or multicomponent.1 by the stethoscope and further fine-tune the Palpation of the right carotid arterial pulse position of the already properly positioned should also be performed from the patient’s chest piece. The eyes of the examiner con- right side. It can be done comfortably by using tinue to observe the venous neck pulsations the examiner’s left thumb when the left hand throughout this entire process. is free. When the right hand is free, the left carotid pulse is palpated with the examiner’s CONSISTENT APPROACH TO right index and middle . The carotid AUSCULTATION upstroke is felt after one hears the first heart sound and before one hears the second heart Auscultation should be systematic, with a sound. It is a good method to time systole. consistent approach from patient to patient. LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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One goal of the experienced examiner (while exhalation may slow the briefly, remaining methodical) is to identify memo- prolonging the cardiac cycle and thus provid- rable auscultatory features that are unique to ing more time to listen to a particular mur- the patient (much the same way that one rec- mur. Some subtle auscultatory findings such ognizes the voice of a long-lost acquaintance as rubs, gallops, and rumbles are transient and on the phone). may only be heard briefly during a few cardiac A systematic approach requires that heart cycles immediately after turning the patient sounds should be identified first and murmurs on his or her left side. should initially be ignored. The number of Patients with barrel chests due to dis- heart sounds per cardiac cycle is readily de- ease can be positioned semi-sitting and the termined. Triple rhythms (more than 2 heart stethoscope can be applied in the subxiphoid sounds per cycle) are thus identified early in region. An electronic stethoscope with ambi- the cardiac assessment. Respiratory splitting ent noise reduction may dramatically improve of the second heart sound, heard at the upper tone and clarity of heart sounds in a noisy left sternal border, is also identified and char- environment. acterized early in the examination. IDENTIFYING THE HEART SOUNDS SEQUENTIAL APPROACH The first and second heart sounds actu- The listening sequence can begin at the ally sound quite different. The first sound is point of maximal impulse at the cardiac apex, longer and lower pitched. The second sound or at the upper right sternal border. The is shorter and higher pitched. The loudness stethoscope is then walked up and down the of heart sounds changes with location. The left sternal border. The neck, clavicles, and second heart sound is louder at the base (up- other parts of the chest are also an integral per right and left sternal borders). The first part of the auscultatory examination. Some- heart sound is louder at the apex. This phe- times the heart sounds are distant and difficult nomenon is made most obvious by putting to hear but are still transmitted to the . the patient in the left lateral decubitus posi- Listening with the diaphragm over the right tion, finding the point of maximal impulse, clavicle may be very rewarding in such cases. putting the diaphragm there, and then com- An amplifying electronic stethoscope is also paring the relative loudness of the first and quite useful in such cases. second heart sounds by alternatively listen- ing back and forth between the apex and the SELECTIVE HEARING base. At slow heart rates, systole is noticeably Hearing should be selectively tuned for one shorter than . Consequently, the sec- auscultatory feature at a time. The rationale ond heart sound follows the shorter pause, is the same as when listening to an orchestra while the first heart sound follows the longer playing. After an initial overall impression of pause. sound, it is necessary to selectively tune in to an individual instrument to truly appreciate it. THE FIRST HEART SOUND

TIPS FOR IMPROVING AUSCULTATION The first heart sound (S1) marks the end of diastole and the beginning of systole. It is Distant, faint heart sounds may be heard heard at the time that the mitral and tricus- better by asking the patient to exhale. It pid valves are closing.2 The systolic carotid should be kept in mind, however, that held upstroke becomes palpable after (never be- expiration affects some auscultatory findings. fore) S1 is heard. S1 is produced predomi- Deep inspiration followed by slow deliberate nantly by mitral leaflet closure (M1). Tricuspid LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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valve closure (contributing to S1—making it components), but not louder. If S1 is louder, M1T1) can be heard best at the lower left or only present at the left lower sternal border, sternal border. Tricuspid closure closely fol- the inference is that the mitral component of lows the mitral component. This combined the first heart sound is decreased and the ex- first heart sound is slightly longer in compar- aminer is mainly hearing the tricuspid compo- ison to the shorter and sharper second heart nent of S1. sound. In other words, S1 is longer and also The intensity of S1 is variable in patients lower pitched compared to S2. S1 may sound with , and in those with a single, or closely spilt (reduplicated). The de- variable PR interval such as complete heart gree of reduplication of S1 does not change block and Wenckebach second-degree heart with respiration. block. Although the intensity of the first heart The examiner should become proficient in sound varies to some degree in most pa- distinguishing S1 from S2 and in recognizing tients with atrial fibrillation, it may be diffi- changes in loudness of S1. The intensity of S1 cult to ascertain that this indeed is the case is affected by the atrioventricular (AV) con- with rapid “irregularly irregular”heart sounds. duction interval. Patients with short AV in- The following technique for eliciting vari- tervals have a loud first heart sound. This is able intensity of heart sounds should be prac- illustrated in patients with the short PR in- ticed and honed in patients with atrial fib- terval of Wolff-Parkinson-White syndrome. In rillation and a slow ventricular response. It a patient with a short PR interval, the first also works well in patients with complete heart sound is loud owing to the short time heart block since the ventricular rate is usu- interval between maximal mitral leaflet open- ally slow. This approach for detecting vari- ing (after the P wave) and mitral leaflet clo- able intensity of the first heart sound con- sure (after the QRS). S1 is also loud in mitral sists of sliding the stethoscope away from stenosis. the area of maximal intensity to the point S1 is soft in patients with a long PR interval where the first heart sound is completely in- and delayed atrioventricular conduction. S1 audible. The extreme of “variable intensity” is produced when ventricular pressure rises is “audible S1 alternating with inaudible S1” rapidly during systole, exceeding the respec- and is a good way to start learning to recog- tive atrial pressures, and closing the AV valves. nize variable intensity of heart sounds. It is In patients with , S1 may be soft easier to detect a first heart sound that ac- or inaudible owing to a slower rate of ventric- tually disappears completely and returns in- ular pressure rise in systole. In patients with termittently. The examiner should progres- left heart failure, S1 may be inaudible where it sively distance the stethoscope from S1 so is usually heard the best—at the apex. In such that it becomes fainter and fainter and eventu- patients a simple stethoscope maneuver may ally becomes inaudible. In patients with vari- be very rewarding. The diaphragm is pressed able intensity, there will be a spot along this firmly at the apex while paying attention to stethoscope path where S1 “comes in and the intensity of S1. It is then pressed firmly at out”during different cardiac cycles. Once the the left lower sternal border, again selectively ear is trained, it will become easy to detect listening to S1. This alternating placement of more subtle variations in the intensity of heart the stethoscope is repeated as many times as sounds. necessary. In the normal patient, S1 will be louder at the apex (the so-called mitral area). THE SECOND HEART SOUND In this same normal patient, at the left lower sternal border (the so-called tricuspid area) S1 For the author, the auscultatory anchor- may be reduplicated (closely split mitral and point to auscultation is actually the second, tricuspid components), slightly longer (owing rather than the first, heart sound. This is done to the presence of both mitral and tricuspid by identifying the second heart sound and LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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“anchoring” the timing of everything else to tricuspid and closure sounds, re- this sound. Our reasons for using and teach- spectively. Fortunately, the aortic component ing this approach are explained below. of the second heart sound (A2) is heard there The second heart sound has been called as well. Thus, one can usually hear both the the key to heart disease.3 For us, it is also first and second heart sounds at the lower the key to beginning the auscultatory exam- left sternal border and at the apical left lateral ination. The aortic component of the second chest area. heart sound originates from clo- sure. In the normal patient it is easily heard THE THIRD HEART SOUND and identified at the upper left sternal border. Furthermore, it is widely transmitted and is The third heart sound, also called S3 gallop, usually audible in all the important ausculta- ventricular gallop, or protodiastolic gallop, is tory areas of the chest and neck. The second a low-frequency sound that is best heard with heart sound is sharper and shorter than the the bell of the stethoscope held lightly against first heart sound and can become easily rec- the skin. It is frequently present in healthy ognizable with practice. Phonating the first children and healthy young adults, and may and second heart sounds as “lub” and “dup,” be referred to in these cases as a physiologic respectively, illustrates that difference. S3. The physiologic S3 disappears by age 30 The beginning “stethoscopist” should be- at the latest. The finding of an S3 in older come thoroughly familiar with the second adults is usually ominous and is typically as- heart sound by listening to as many differ- sociated with decompensated systolic heart ent patients as possible. As mentioned, in ad- failure.4 It may disappear after medical treat- dition to “sharper and shorter,” the second ment. An S3 may be heard without heart fail- heart sound is widely transmitted across the ure in patients with diastolic . chest and should be listened to at the upper This may be due to hemodynamically signifi- right sternal border, upper left sternal border, cant mitral regurgitation. Congenital heart de- lower left sternal border, and in the apical left fects that cause left to right shunts may give lateral chest area. rise to an S3 owing to torrential early diastolic At the upper right sternal border, the blood flow into the left . For exam- second heart sound is usually louder than ple, patent ductus arteriosus, atrial septal de- anywhere else on the chest and it is single. It fect, and large ventricular septal defects can is single there, because at the upper right ster- all have an S3 in addition to their other aus- nal border, all one hears is aortic valve closure. cultatory features. The aortic valve is very close to the stetho- scope, which is why the second heart sound is SNAPS, PLOPS, AND KNOCKS louder there than anywhere else on the chest. At the upper left sternal border, the sec- Loud early diastolic sounds are not gallops.5 ond heart sound may be split. This may be The stenotic mitral valve opens with a loud mimicked by saying the word “butter” (the sound early after S2. This is the opening splitting is the “ter” in butter). The split- snap (OS) of mitral stenosis. As mitral steno- ting is called reduplication. The second heart sis progresses, left atrial pressure rises and sound is reduplicated at the upper left ster- the opening snap moves closer to S2. In nal border because in addition to aortic valve other words, the S2-OS interval gets shorter closure, one may also hear pulmonic valve with worsening mitral stenosis. There may closure. At the upper left sternal border— be an identical-to-the-ear, loud, early diastolic the pulmonic valve is very close to the sound in patients with a left atrial . stethoscope. This pedunculated large tumor abruptly stops The lower left sternal border and the apical short (restrained by the stalk) in early dias- left lateral chest area are best for transmitted tole on its path toward the mitral orifice, LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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creating a halting sound that is called a tumor entiate an S4 followed by S1 from S1 followed plop. by an ejection sound. Both S1 and ejection Finally, patients with constrictive pericardi- sounds have high-frequency components that tis due to thickened or calcified remain audible even when the bell is pressed may develop an early to middiastolic sound down. An S4 will become muffled or will com- owing to abrupt cessation of ventricular fill- pletely disappear when the skin is stretched ing. This is termed a pericardial knock. by pushing down on the bell. Some very-low- An echocardiogram can easily allow dis- frequency components of S4 may be palpable tinction between a snap and a plop. The at the apex without being audible. The search thick, hockey-stick-shaped stenotic mitral for an S4 should therefore combine palpation valve is easily distinguished from a large left with auscultation. By looking at one’s fingers atrial tumor using echocardiography. On the as they palpate the precordium, it may also other hand, pericardial constriction should be possible to see the S4. So an S4 can be be sought by searching for physical signs heard, felt, and seen in some patients. Owing in addition to ordering imaging studies such to the loss of atrial contraction, the S4 disap- as echocardiograms, chest computed tomo- pears with onset of atrial fibrillation. Having graphic scans, and cardiac magnetic reso- the patient several times may elicit a nance imaging. Patients with constrictive previously inaudible gallop. may exhibit dramatic abnormali- A right ventricular S4 may be found in con- ties in jugular venous pulsations, the pericar- ditions with right ventricular diastolic dys- dial knock may change in loudness with stand- function. Important clinical examples are pul- ing and squatting (louder on squatting), and monary hypertension and pulmonic valve there may be systolic retraction of the apical stenosis. Two important clues help distin- impulse. guish a right-sided S4: location and respira- tory variation. A right-sided S4 is best heard at the left lower sternal border rather than at THE the apex. A right-sided S4 gets louder on in- spiration. A left-sided S4 does not change dur- The fourth heart sound is also called an S4 ing respiration but may get fainter on inspira- gallop, atrial gallop, or presystolic gallop. It re- tion because of an increase in interposed lung quires active late diastolic left atrial contrac- tissue between the stethoscope and the left tion. The priming booster-pump action of left ventricle. atrial contraction may cause an audible low- frequency sound in clinical situations with di- astolic dysfunction. The S4 sound is caused MURMURS by tensing of the left ventricular myocardium and mitral valve apparatus. Important clini- Murmurs should always be evaluated af- cal examples include uncontrolled hyperten- ter the heart sounds. The carotid upstroke sion and acute . An S4 or the apical impulse should be used to time may also be present in , hy- the murmurs to decide if they are systolic pertrophic cardiomyopathy, and acute mitral or diastolic. Systolic murmurs can be simpli- regurgitation. fied into 2 broad categories: ejection quality The S4 should be searched for intention- or not.7 The systolic ejection murmur (SEM) ally. Otherwise it may be overlooked even by is over diagnosed in patient progress notes. an experienced examiner. An S4 is best heard To be ejection quality, the murmur should with the bell of the stethoscope held lightly get progressively louder, reach a peak, and against the skin.6 Forceful pressure may oblit- then get progressively softer. Murmurs can erate it. Increasing and decreasing the bell be further described as harsh, blowing, or pressure during auscultation can help differ- musical. LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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GRADING OF MURMUR LOUDNESS Seven of 10 school-age children can have inno- cent murmurs on careful auscultation.9 Flow The loudness of murmurs can be consis- in the may be audible as a tently classified by using the following grad- musical vibratory still’s murmur. ing system. Grade 1/6 murmurs are barely au- A systolic-diastolic venous hum is a dible even by experienced examiners under common normal physiological murmur in ideal listening conditions. They have been re- children, rare in adults.10 It is due to the ferred to as the “absence of silence.”Grade 2/6 torrential downward rush of blood from the murmurs are soft, audible with selective con- jugular veins into the superior vena cava. It centration, but may not be immediately appar- may rarely be loud and roaring, with a palpa- ent during a casual examination. Grade 3/6 ble thrill. It is usually best heard on the right murmurs are unmistakable. They are immedi- side of the neck, just over the clavicle with ately audible on applying the stethoscope, but the patient sitting. It decreases or disappears there is no palpable thrill. The presence of a when the patient assumes the recumbent po- palpable thrill makes the murmur a grade 4/6 sition. When the venous hum is also audible murmur or greater. Grades 5 and 6 are rare. at the right sternal border, over the sternum If the stethoscope can be partly lifted off the itself, or on the left sternal border, it can be chest, and the already loud murmur remains mistaken for the murmur of a patent ductus audible, the murmur is grade 5/6. Grade 6/6 arteriosus, or for a to-and-fro bellows-like murmurs are audible with the stethoscope aortic stenosis/regurgitation murmur. As held off the chest. To get transmitted through opposed to aortic and ductal murmurs, the the air to the stethoscope, these rare 6/6 venous hum can be dramatically altered by murmurs can be harsh with low frequencies, certain maneuvers. It can be obliterated by which may give them a sound much like the pressure over the jugular vein above the buzzing of a bee, or the clearing of a throat. point of maximal murmur, and can be made to decrease or disappear by changing from Clinical example the sitting to the supine position. Turning the A new systolic murmur in the course of head to the left will increase the loudness of acute myocardial infarction may be due to a a right supraclavicular venous hum. newly ruptured mitral , or it Other innocent murmurs are the supraclav- may be due to ventricular septal rupture. A icular , mammary souffle, and cardiores- mitral regurgitation jet directed into the pos- piratory murmur. teriorly located left is highly unlikely to create a palpable anterior precordial thrill AORTIC STENOSIS along with the murmur. Conversely, the jet of blood traveling from the high pressure pos- Patients with aortic stenosis invariably have teriorly located left ventricle, through a rup- a murmur. The typical murmur of aortic steno- tured ventricular septum into the anteriorly sis is systolic, ejection quality (also referred located lower-pressure right ventricle is quite to as crescendo-decrescendo). Ejection mur- likely to be both palpable and audible (grade murs start out soft, get progressively louder 4/6) at the anterior precordium. Simply plac- as blood flow accelerates across the stenotic ing the hand on the chest (to feel for the pres- valve, and, after reaching a peak intensity, ence or absence of a thrill) may help distin- become progressively softer. As the severity guish one murmur from the other. of stenosis worsens, the murmur reaches its peak later in systole (Fig. 2). INNOCENT MURMURS Patients with bicuspid aortic valves have a loud, early systolic ejection click prior to Murmurs in children and adolescents may the onset of the systolic murmur.11 Early sys- indicate congenital or acquired heart dis- tolic ejection clicks should be distinguished ease. More often they are innocent murmurs.8 from split first heart sounds. Aortic ejection LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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hemodynamically significant. Older patients may have atrial gallops with milder degrees of aortic stenosis because the left ventricle is noncompliant for other reasons—such as co- existing hypertension, or simply just due to the aging process. Conversely, the absence of an atrial gallop at any age makes severe aortic stenosis unlikely. Left ventricular ejection time may also be- come progressively prolonged by severe aor- tic stenosis. The resulting delayed closure of the stenotic aortic valve is manifested on aus- cultation as paradoxical splitting of the sec- ond heart sound. The unaffected P2 is audi- ble earlier than the delayed A2 in expiration. The second heart sound is split on expiration and becomes single on inspiration. This is the opposite of the normal inspiratory splitting of the second heart sound, hence the term para- doxical splitting. The intensity of A2 decreases with worsen- ing aortic stenosis. When the aortic leaflets become immobile, A2 becomes completely Figure 2. Auscultatory findings in aortic stenosis: inaudible. The examiner only hears a second ejection crescendo-decrescendo systolic murmur, heart sound (P2) in the pulmonic area. To ejection click, atrial gallop, wide paradoxical split- demonstrate this, the stethoscope is applied ting of the second heart sound (P2 precedes A2 to the upper left and upper right sternal bor- in expiration), delayed peaking of the systolic mur- ders in alternating fashion. The second heart mur with severe aortic stenosis. sound, in this case, is only heard at the upper left sternal border (pulmonic area). Since A2 sounds are loud and can be phonated as “lub- is gone, the second heart sound also remains TUK ... dup”(S1TUK ... S2). The “TUK” of single and does not split with respiration. aortic ejection occurs later than the tricus- While listening to the murmur of aortic pid component of the first heart sound (T1). stenosis, the patient may have premature The aortic ejection click TUK is louder, more ventricular contractions. The listener should widely transmitted, and may be loudest in the compare the loudness of the murmur from mitral area (in spite of its aortic origin). This beat to beat. The murmur that immediately aortic ejection click does not vary with res- follows the compensatory pause will be much piration. Patients with pulmonic stenosis may louder than the previous and subsequent also have an ejection click. The ejection click murmurs. of pulmonic stenosis decreases with inspira- tion, and the intensity of the pulmonic ejec- AORTIC REGURGITATION tion click can vary dramatically during the res- piratory cycle. The auscultatory hallmark of aortic re- As the left ventricle becomes hypertro- gurgitation is a high-pitched, blowing early phied, stiff, and noncompliant owing to the diastolic murmur. Hearing this subtle mur- aortic valve obstruction, the patient may de- mur in a critical care setting may dra- velop an audible atrial gallop (S4).12 The pres- matically influence diagnosis and treatment. ence of an atrial gallop in a young patient with A patient with may undergo aortic stenosis suggests that aortic stenosis is transesophageal echocardiography instead of LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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coronary . This murmur begins with the second heart sound, but may quickly taper and fade away. Patients with aortic re- gurgitation often have a systolic murmur as well. The sometimes loud but nondiagnostic systolic high-flow murmur may distract the in- experienced listener from the subtle but di- agnostic diastolic murmur. The examiner may be able to hear the diastolic murmur by hav- ing the patient sit, lean forward, exhale, and hold his or her breath. The diaphragm of the stethoscope should be pressed very hard while listening for this murmur on both sides of the upper sternal border.13 Patients with isolated aortic regurgitation may have an obvious systolic flow murmur with a subtle diastolic murmur. The flow murmur may get mistakenly dismissed as a functional innocent murmur if the listener does not hear the diastolic murmur, which is never functional (Fig. 3). Patients with both aortic regurgitation and aortic stenosis may have a harsh systolic murmur along with the diastolic blowing murmur. This combined Figure 3. Auscultatory findings in aortic regurgita- systolic-diastolic murmur sounds like a bel- tion: the murmur of aortic regurgitation begins in lows and has been called a to-and-fro mur- early diastole; there may be a systolic flow murmur; mur. The listener should also analyze the heart the diastolic murmur may become longer with pro- sounds. A decreased M1 may be due to pre- gressing severity. mature closure of the mitral valve by the jet of acute severe aortic regurgitation. A loud Hill’s sign: accentuated leg systolic pressure A2 is evidence against a calcified immobile with greater than 40 mmHg difference from stenotic aortic valve. An ejection click pro- the systolic pressure vides evidence for a bicuspid aortic valve. Muller’s sign: pulsation of the uvula with each Patients with worsening chronic severe aortic heartbeat regurgitation may actually develop a decrease Palmar click: palpable systolic flushing of the in the duration and loudness of their diastolic palms murmurs. At the same time they may exhibit Quincke’s pulse: cyclic reddening and blanch- many prominent physical findings owing to ing of the nail capillaries their bounding arterial pulses. The eponyms Traube’s sign: loud “pistol shot” sound heard of these physical findings are listed below. over the Water hammer pulse: brisk femoral pulsation Corrigan’s pulse: prominent pulsations of the similar to that felt with a water hammer—a ∗ carotid Victorian toy. Bisferiens pulse: double systolic arterial impulse—the so-called twice-beating heart De Musset’s sign: head nodding with each ∗The water hammer was a glass tube filled partly with wa- heartbeat ter or mercury in a vacuum. The water or mercury pro- Duroziez’s sign: systolic and diastolic femoral duced a slapping impact when the glass tube was turned artery bruit over. LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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One reason for stressing these physical find- ...ki (in mid-to-late systole) ...pause ...tup ings in an article on auscultation is that the (S2). The midsystolic click (produced by the diastolic murmurs of aortic regurgitation and prolapsing mitral valve) may be followed by a of pulmonic regurgitation sound the same, murmur of mitral regurgitation. Attention to but only the murmur of aortic regurgitation the location of the murmur helps identify the will be accompanied by the above physical prolapsing leaflet. The mitral regurgitation jet findings. in is directed away from the culprit leaflet. Posterior mitral leaflet pro- MITRAL REGURGITATION lapse will direct the mitral regurgitation jet to the anterior portion of the left atrium. The The murmur of mitral regurgitation is murmur in this case of posterior mitral leaflet plateau-shaped. It does not get louder and prolapse will be heard best at the base of softer like an ejection murmur. When it is the heart at the upper left sternal border. In holosystolic, it begins in early systole and re- contrast, the murmur of anterior mitral leaflet mains uniform until it ends with S2. The mur- prolapse is directed toward the posterior por- mur is typically heard well at the apex and tion of the left atrium. Consequently, the ex- may extend to the left axillary region. Un- aminer may be surprised by a murmur below like the murmur of aortic stenosis, it does not the left scapula in patients with anterior mitral radiate to the neck. Mitral regurgitation can leaflet prolapse. Since the heart sounds may be present in clinical entities such as mitral not be transmitted to the back along with the valve prolapse, inferior myocardial infarction, murmur, the unsuspecting or inexperienced dilated cardiomyopathy, and hypertrophic examiner may dismiss this murmur as breath cardiomyopathy. sounds. The distinction between anterior and posterior leaflet prolapse is clinically impor- MITRAL VALVE PROLAPSE tant. The operation to repair posterior mitral leaflet prolapse is technically less challenging. An alternate name for mitral valve prolapse The murmur and click of mitral valve pro- is a name that describes the auscultatory find- lapse are dramatically altered by standing and ings: click-murmur syndrome. In turn, the squatting. Standing brings the click closer to click of mitral valve prolapse has an alternate S1 and may make it easier to hear separately name that describes it by what it is not: none- from S1 and S2. Squatting moves the click jection click. The term nonejection refers to closer to S2 but, more importantly for the ex- the timing. Mitral valve prolapse was not de- aminer, increases the loudness of the late sys- scribed until 1963. Mid-to-late systolic clicks tolic murmur.14 were thought to be extracardiac until Bar- low’s description of the intracardiac mid-to- HYPERTROPHIC CARDIOMYOPATHY late systolic buckling of the mitral valve into the left atrium. This negative name may be Hypertrophic cardiomyopathy is a leading thought to imply (wrongly) that a mid-to-late cause of sudden death in the young athlete, systolic nonejection click is also a noncardiac so it is important to recognize this murmur. As click. opposed to the fixed gradient of valvular aor- Ejection clicks have already been discussed. tic stenosis, patients with hypertrophic car- They closely follow the first heart sound and diomyopathy have murmurs that are altered in may be the best clinical clue to the pres- a unique manner by changes in cardiac hemo- ence of a bicuspid aortic valve. In contrast, dynamics. A sequence of serial hemodynamic the nonejection clicks of mitral valve prolapse events can occur as outflow to the from occur later in systole. The timing of the the left ventricle becomes hampered by lo- phonic for the mitral prolapse click (ki) calized ventricular septal hypertrophy below sounds like “look it up”—luh (S1) ... pause the aortic valve. Left-ventricular ejection is LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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followed by outflow obstruction. This may be ing down”and closing the glottis will increase followed by mitral regurgitation, which serves the intrathoracic pressure and decrease left to depressurize the outflow obstruction. The ventricular volume—increasing the loudness sequence of ejection, obstruction, regurgita- of the murmur. tion can also explain the behavior of murmurs that can be heard in this entity. The left ven- MYOCARDIAL INFARCTION AND MITRAL tricle begins to eject in systole, which may REGURGITATION give rise to an ejection murmur. In ausculta- tion terms, the examiner can clearly distin- Acute inferior myocardial infarction can be guish the first heart sound as a separate sound accompanied by acute mitral regurgitation. In before the murmur begins. The hypertrophy contrast to chronic mitral regurgitation, acute of the can create a regurgitation into a noncompliant left atrium dynamic gradient in the left-ventricular out- may create auscultatory evidence of that fact. flow, making the murmur respond dramati- A loud S4 suggests a forceful atrial contrac- cally to dynamic auscultation. Having the pa- tion. A loud P2 indicates pulmonary hyperten- tient squat during auscultation will decrease sion. The murmur of acute mitral regurgita- the loudness of the murmur. When the pa- tion may be lower pitched (“rumbling”) than tient stands back up from the squatting po- the typical high-pitched (“blowing”) murmur sition, the murmur becomes much louder. In of chronic mitral regurgitation. the squatting position, there is increased ve- nous return to the heart, which increases the PERICARDIAL RUB left ventricular volume and reduces the de- gree of outflow obstruction. On standing back In the clinical practice of medicine it is up, the left-ventricular volume decreases be- rare for a physical finding alone to make a cause of the decreased venous return and also definitive diagnosis.15 The presence of a peri- because of the usually increased heart rate. cardial rub on auscultation is sufficient to The dynamic nature of the murmur is also make the diagnosis of pericarditis. A patient exemplified by performing a Valsalva maneu- with new-onset chest pain and a pericardial ver. In hypertrophic cardiomyopathy, “bear- rub on auscultation will not get whisked to

Figure 4. Simulating a rub by holding the stethoscope and scratching the dorsal surface of the hand. LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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the catheterization laboratory from the emer- gency department, and may get an echocar- diogram instead. Pericardial rubs are easy to diagnose when they have all 3 components— two components are heard in diastole and one is heard in systole. A classic 3-component rub can be phonated as “cha-cha-cha.” Rubs have been compared to the creaking leather of a new saddle, or the crunching sound made by stepping on fresh dry snow. A rub may sound superficial to the examiner—as if it is originating “halfway up the stethoscope.” Rubs may sometimes sound musical, like the sound of a wet sliding over glass, and unfortunately may consequently get mistaken for murmurs. Some rubs sound like sandpa- per; hence the term friction rub. To us, the term friction rub belongs in the Department of Redundancy Department. Pericardial rubs are notoriously evanescent; so they should be sought “repeatedly and often.” Post–open heart surgery and dialysis patients are quite likely to develop transient rubs while in the hospital. A 3-component rub can be mimicked by holding the diaphragm of the stethoscope in the clenched hand and delivering 3 quick scratches to the outside surface of that hand while listening with the stethoscope (Fig 4).

AUSCULTATION PHONICS

Heart sounds can be illustrated by using familiar sounds or words to mimic their na- ture and timing. Figure 5 shows the timing of the nonejection click of mitral valve prolapse. The click is relatively loud and sharp, so the Figure 5. Phonics illustrating the timing of clicks consonant “k”is employed. The timing of the and gallops. S1, midsystolic click, and S2 sequence is re- markably similar to the phrase “look it up.” purpose. Finally, the last “ta” of the Spanish In contrast, the timing of an ejection click in word “patata” is used to illustrate the timing cases of bicuspid aortic valve is approximated of the middiastolic S3 gallop. The words “Ten- by saying “lutuk” quickly (because the delay nessee”and “Kentucky”have also been used to between S1 and the ejection click is much illustrate the timing of S4 and S3 respectively. shorter). The timing of S4 followed by S1 is no different, but there is no click. Gallops rarely CONCLUSION sound sharp, so no consonant is used. Instead, “luh”illustrates the muffled thud of the typical In summary, the goal of this article is to S4. “Luh lub” said quickly accomplishes this present practical information on the use of the LWW/CCNQ LWWJ306-08 March 7, 2007 23:32 Char Count=

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stethoscope. Phonics are presented to clar- sive because it is difficult to find in the cur- ify the differences in the timing of different rent literature. The clinical sections attempt to heart sounds. This is neither a comprehen- go beyond what is available in standard text- sive, nor a balanced, presentation. The focus books by providing information and stetho- is on selected practical aspects. The section scope techniques that are valuable and useful on choosing and using a stethoscope is exten- at the bedside.

REFERENCES

1. O’Rourke MF.The arterial pulse in health and disease. 9. Fogel DH. The innocent systolic murmur in children: Am Heart J. 1971;82(5):687–702. a clinical study of its incidence and characteristics. 2. Laniado S, Yellin EL, Miller H, Frater RW.Temporal re- Am Heart J. 1960;59:844–855. lation of the first heart sound to closure of the mitral 10. Fowler NO, Gause R. The cervical venous hum. Am valve. Circulation. 1973;47(5):1006–1014. Heart J. 1964;67:135–136. 3. Leatham A. The second heart sound, key to ausculta- 11. Waider W, Craige E. First heart sound and ejec- tion of the heart. Acta Cardiol. 1964;19:395. tion sounds. Echocardiographic and phonocardio- 4. Timmis AJ. The third heart sound. Br Med J (Clin Res graphic correlation with valvular events. Am J Car- Ed). 1987;294(6568):326–327. diol. 1975;35(3):346–356. 5. Martinez-Lopez JI. Sounds of the heart in diastole. Am 12. Wood P. Aortic stenosis. Am J Cardiol. 1958;1(5): J Cardiol. 1974;34(5):594–601. 553–571. 6. Bethell HJ, Nixon PG. Understanding the atrial sound. 13. Dressler W, Rubin R. Complex shape and variability Br Heart J. 1973;35(3):229–235. of the diastolic murmur of aortic regurgitation. Am J 7. Leatham A. Splitting of heart sounds and a Cardiol. 1966;18(4):616–621. classification of systolic murmurs. Circulation. 14. Devereux RB, Perloff JK, Reichek N, Josephson ME. 1957;16(3):417–421. Mitral valve prolapse. Circulation. 1976;54(1):3–14. 8. Weaver WF, Walker GH. Innocent cardiovascular 15. Spodick DH. Pericardial rub. Prospective, multiple murmurs in the adult. Circulation. 1964;29:702– observer investigation of pericardial friction in 100 707. patients. Am J Cardiol. 1975;35(3):357–362.