Heart murmurs are heard best at five specific spots on the chest, each corresponding to a region where blood flow through a particular valve or structure sends vibrations most clearly to the surface. These spots are not directly over the valves themselves, which is a common source of confusion. Instead, they sit along the path that sound travels as it moves through the heart chambers and great vessels toward the chest wall. Understanding where to place the stethoscope and why those spots work is the foundation of cardiac auscultation.
The Five Classic Auscultation Points
The traditional teaching identifies four valve-related areas plus a fifth listening post known as Erb’s point. Each is named for the valve best assessed there, though the naming convention can be misleading because the stethoscope is not sitting directly on top of the valve in question. The areas are defined by their relationship to the sternum (breastbone) and the intercostal spaces, which are the gaps between ribs counted downward from the collarbone.
- Aortic area: Second intercostal space at the right sternal border. This is where you listen for murmurs related to the aortic valve, particularly aortic stenosis, which produces a harsh crescendo-decrescendo sound radiating toward the neck.
- Pulmonary area: Second intercostal space at the left sternal border. Murmurs arising from the pulmonary valve, such as pulmonary stenosis, are best picked up here.
- Erb’s point: Third intercostal space at the left sternal border. This spot sits between the aortic and tricuspid areas and is especially useful for detecting aortic regurgitation, which produces a soft, blowing diastolic murmur that can be easy to miss elsewhere.
- Tricuspid area: Fourth or fifth intercostal space at the left lower sternal border. Murmurs from the tricuspid valve, as well as ventricular septal defects, are heard here.
- Mitral area: At the cardiac apex, which is typically in the fifth intercostal space at the midclavicular line on the left side. This is where mitral regurgitation and mitral stenosis murmurs are loudest.
A physiologic revision of these areas, proposed decades ago, argued that the traditional names were too rigid. That revision suggested broader zones rather than pinpoint spots, with the “left ventricular area” centering on the apex beat and extending medially and laterally, the “aortic area” spanning from the third left interspace across the manubrium to the first through third right interspaces, and the “pulmonary area” covering the second left interspace up toward the clavicle and down to the third interspace.1The American Journal of Medicine. A revision of the “classic” areas of auscultation of the health: A physiologic approach In practice, most clinicians still learn the five discrete points first, then develop a sense for how sound spreads across these wider zones with experience.
Why the Stethoscope Goes There and Not Over the Valve
The heart’s valves are buried deep within the mediastinum, and sound does not travel in a straight line from a valve to the nearest patch of skin. Heart sounds and murmurs originate as vibrations of the valve leaflets and the turbulent blood flow passing through them, then travel as transverse vibrations along the walls of the ventricles and great vessels. Where those structures make contact with the inner chest wall, vibrations emerge at the surface and radiate outward like ripples.2PubMed Central. Biophysics of Heart Sounds and Its Application to Clinical Auscultation The aortic valve, for example, sits in the center of the chest, but the ascending aorta angles to the right and comes close to the chest wall near the second right intercostal space. That is why the “aortic area” is there rather than directly over the valve.
An additional principle is that murmurs are loudest in the cardiac chamber or vessel that is less distensible, meaning the cavity that stretches less easily.2PubMed Central. Biophysics of Heart Sounds and Its Application to Clinical Auscultation This is why mitral regurgitation, where blood jets backward into the relatively thin-walled left atrium, produces a loud murmur at the apex even though the regurgitant flow is heading away from the chest wall. The left atrium vibrates more readily than the thick-walled left ventricle, and those vibrations propagate to the surface.
The Story Behind Erb’s Point
Erb’s point is sometimes treated as an afterthought in teaching, but it is arguably the most clinically versatile of the five locations. Historically, the name is linked to Wilhelm Erb, a nineteenth-century neurologist who specialized in the neurological complications of syphilis. Syphilitic aortitis was a common cause of aortic valve incompetence in his era, and the resulting murmur of aortic regurgitation happened to be best heard at the third left intercostal space near the sternum. That association is believed to be why Erb’s name became attached to this auscultation point.3PubMed. Searching the Roots of Erb’s Auscultation Point
Today, syphilitic aortitis is rare, but Erb’s point remains valuable. Because it sits at a crossroads between the aortic, pulmonary, and tricuspid areas, it can pick up murmurs that might be faint at any single classic point. Aortic regurgitation, in particular, is notoriously easy to miss if you skip Erb’s point and listen only at the second right interspace.
Matching Murmurs to Locations
Knowing the five points is only useful if you understand which murmur belongs where. The location of maximum intensity, combined with the timing of the murmur within the cardiac cycle, gives a strong first guess about which valve is involved.
Aortic stenosis is the textbook example of a murmur best heard at the aortic area. It peaks in midsystole and often radiates to the carotid arteries in the neck. Aortic regurgitation, by contrast, is a diastolic murmur best heard at Erb’s point or the aortic area, often requiring the patient to sit up, lean forward, and hold their breath at the end of expiration so the heart moves closer to the chest wall.
Mitral regurgitation produces a holosystolic (lasting all of systole) murmur loudest at the apex, with radiation toward the left axilla. In rare and severe cases, the murmur of mitral regurgitation can radiate in unusual directions. A medical curiosity first documented in the early 1960s showed that the murmur could travel all the way to the top of the patient’s head, a finding known as the Merendino sign.4PubMed Central. Murmur on top of the head: bioprosthetic mitral valve insufficiency This is an extreme example, but it illustrates how sound vibrations can propagate far from their origin along bony structures.
A ventricular septal defect produces a loud holosystolic murmur best heard at the left lower sternal border, the tricuspid area. In small defects, the murmur can be surprisingly loud because the jet of blood passing through a tiny hole generates intense turbulence. The location of peak intensity can shift slightly depending on the angle of the jet: sometimes it is heard best at the mid or upper left sternal border instead.5PubMed Central. Diagnosis and Management of Ventricular Septal Defects
How Breathing and Body Maneuvers Change What You Hear
Placing the stethoscope in the right spot is the starting point, but experienced clinicians go further by using dynamic maneuvers to tease apart murmurs that might otherwise sound alike. This is sometimes called dynamic auscultation, and it exploits the way that changes in blood return to the heart, blood pressure, and heart chamber size alter murmur intensity.
The simplest maneuver is respiration. When you breathe in, negative pressure in the chest pulls more blood into the right side of the heart, temporarily increasing flow across the tricuspid and pulmonary valves. This means right-sided murmurs get louder with inspiration. A landmark study found that this inspiratory augmentation identified right-sided murmurs with perfect sensitivity and about 88% specificity.6PubMed. Bedside diagnosis of systolic murmurs If a murmur gets louder when the patient breathes in, you can be fairly confident it originates from the right heart. This principle is sometimes called Carvallo’s maneuver and is one of the most reliable bedside tests in cardiology.7PubMed. Aids to cardiac auscultation
A case report illustrates this dramatically: a patient with straight back syndrome had a systolic murmur that varied from a barely audible grade I during inspiration to a grade IV during expiration. Catheterization showed that the narrow chest cage was compressing the right ventricular outflow tract only when the lungs deflated, creating a pressure gradient that disappeared with each breath in.8PubMed Central. A mechanism of a cardiac murmur with respiratory variation in a patient with straight back syndrome
Beyond respiration, three other maneuvers come up repeatedly in clinical practice. The Valsalva maneuver (bearing down as if straining) reduces blood return to the heart, shrinks the ventricles, and makes most murmurs softer. The exception is hypertrophic cardiomyopathy, where the reduced ventricular volume worsens the obstruction and makes the murmur louder. The same study found that a Valsalva-induced increase in murmur intensity identified hypertrophic cardiomyopathy with 65% sensitivity and 96% specificity.6PubMed. Bedside diagnosis of systolic murmurs Squatting, which suddenly increases blood return and raises afterload, has the opposite effect: it makes the hypertrophic cardiomyopathy murmur softer and makes the murmurs of mitral regurgitation and ventricular septal defects louder.
Handgrip is another useful tool. Clenching the fists raises afterload (the resistance the heart pumps against), which amplifies regurgitant murmurs because more blood is pushed backward through a leaky valve. The study found that handgrip augmented the murmur of mitral regurgitation and ventricular septal defects with about 68% sensitivity and 92% specificity.6PubMed. Bedside diagnosis of systolic murmurs These maneuvers change preload, afterload, and chamber dimensions in predictable ways, and together with location and timing, they narrow the diagnostic possibilities significantly.9PubMed. On systolic murmurs and cardiovascular physiological maneuvers
Patient Positioning and Stethoscope Choice
Where you place the stethoscope matters, but so does how the patient is positioned. Mitral stenosis, a low-pitched rumbling murmur, is famously easy to miss unless the patient is rolled into the left lateral decubitus position, lying on their left side. This brings the apex of the heart closer to the chest wall and makes the faint diastolic rumble audible. One study on trainee performance noted that the inability to position patients in the left lateral decubitus position during testing contributed to poor detection of gallop sounds and low-pitched murmurs.10PubMed Central. Teaching Cardiac Auscultation: Effectiveness of Virtual Simulation-Based Training on Improving Cardiac Auscultatory Skills in Post-graduate Trainees in the COVID-19 Era For aortic regurgitation, sitting the patient upright and leaning them forward at end-expiration brings the aortic root closer to the chest, making the soft diastolic blowing murmur easier to catch.
The stethoscope itself plays a role. The bell, when applied lightly, is better for low-frequency sounds like mitral stenosis and S3 gallops. The diaphragm, pressed firmly, filters out low frequencies and is better for high-pitched sounds like aortic regurgitation and normal heart sounds. A study comparing the bell and diaphragm found measurable differences even in blood pressure readings, with the bell tending to yield slightly higher diastolic values, reflecting its greater sensitivity to low-frequency sounds.11PubMed Central. Comparison of stethoscope bell and diaphragm, and of stethoscope tube length, for clinical blood pressure measurement The practical takeaway: use the bell at the apex when hunting for mitral stenosis, and the diaphragm at Erb’s point when listening for aortic regurgitation.
How Reliable Is Human Auscultation
Knowing the right spots and maneuvers does not guarantee accuracy. Auscultation is a skill with wide performance variability, and the evidence on this point is sobering. A systematic review of studies comparing auscultation to echocardiography found that the sensitivity of heart auscultation for detecting valve disease ranged from 30% to 100%, with specificity ranging from 28% to 100%.12BMJ Open. Diagnostic accuracy of heart auscultation for detecting valve disease: a systematic review That is an enormous spread, and it largely reflects differences in examiner skill and the type of valve disease being sought.
Agreement between examiners is also imperfect. A study of general practitioners, cardiologists, and medical students listening to the same patients found that overall agreement on whether a murmur was present averaged about 81% compared with a reference standard, with a median kappa of 0.67. Cardiologists did best, medical students did worst, and having more than five years of clinical experience roughly doubled the odds of agreeing with the reference.13PubMed Central. Interrater and intrarater agreement on heart murmurs Louder, more distinct murmurs were easier to agree on, which makes intuitive sense: a grade III/VI pansystolic murmur is hard to miss, while a faint grade I/VI murmur at the apex can be ambiguous.
Perhaps most striking is that auscultation skills do not automatically improve with seniority. A multicenter study of medical students, trainees, and faculty physicians found that exam scores improved from early to late medical school, but showed no further improvement after that. Practicing physicians and faculty performed no better than students and residents. Only cardiologists with specific auscultation expertise tested significantly above the rest.14JAMA Internal Medicine. Competency in Cardiac Examination Skills in Medical Students, Trainees, Physicians, and Faculty: A Multicenter Study The skill, in other words, is use-it-or-lose-it. Without deliberate practice and feedback, the ear does not sharpen on its own.
Digital Stethoscopes and AI-Assisted Listening
Given the variability of human auscultation, there has been growing interest in whether technology can close the gap. Electronic stethoscopes amplify heart sounds and can filter noise, while AI algorithms trained on thousands of recordings can flag murmurs that a human ear might miss.
A study comparing an electronic stethoscope to a conventional acoustic one for screening children with congenital heart disease found that the electronic device detected murmurs in 64% of confirmed cases versus 58% for the acoustic stethoscope. Both had 100% specificity, meaning neither produced false positives. However, the difference was not statistically significant, suggesting that the electronic stethoscope on its own, without AI analysis, did not offer a meaningful advantage.15PubMed Central. Evaluation of the electronic stethoscope (FONODOC) as a cardiac screening tool during the preoperative evaluation of children
Where things get more interesting is when AI is layered on top. A deep learning algorithm designed to analyze digital stethoscope recordings achieved roughly 93% sensitivity and 86% specificity for detecting clinically significant aortic stenosis. For mitral regurgitation, which is harder to detect by auscultation, sensitivity was lower at about 66%, but specificity was high at roughly 95%.16PubMed Central. Deep Learning Algorithm for Automated Cardiac Murmur Detection via a Digital Stethoscope Platform These numbers are competitive with or better than most human examiners, especially for aortic stenosis. A separate FDA-cleared AI system deployed on a digital stethoscope platform has also shown promise in real-world screening for moderate-to-severe valve disease.17PubMed Central. Artificial-intelligence-enabled digital stethoscope improves point-of-care screening for moderate-to-severe valvular heart disease
These tools still require someone to place the stethoscope at the right spot. The AI analyzes the sound, but the recording quality depends entirely on correct placement over the auscultation points. In that sense, the foundational anatomy is not going away even as the technology improves.
From Ear-to-Chest to the Modern Exam
Before the stethoscope existed, physicians had to press their ear directly against the patient’s bare chest to hear the heart. This “immediate auscultation” was socially awkward and technically limited, making it unpopular in practice.18The American Journal of Cardiology. Milestones in Cardiac Auscultation René Laennec’s invention of the stethoscope in 1816 solved both problems at once, creating a distance between doctor and patient while amplifying the sounds being transmitted. Over the following two centuries, clinicians mapped the relationships between valve anatomy, blood flow, chest wall contact, and sound transmission that produced the auscultation points still in use today.
The stethoscope’s basic design has been remarkably stable since then. Tubing got shorter, earpieces got more ergonomic, and the combination bell-and-diaphragm chestpiece became standard, but the core principle remains the same: channel vibrations from a specific spot on the chest wall through a sealed air column to the examiner’s ears. What has changed most is the recognition that the instrument is only as good as the person wielding it, and that systematic approaches to placement, positioning, and dynamic maneuvers are what separate a useful cardiac exam from a ritual that misses half of what it is listening for.