Heart murmurs are described using a systematic framework that covers timing, location, intensity, quality, shape, and radiation. Each component tells you something different about what the heart is doing, and documenting all of them together gives a complete picture of the murmur. Whether you’re learning cardiac auscultation for the first time or brushing up, this framework is the standard approach used across clinical settings.
Timing: When the Murmur Occurs
Timing is the single most important feature because it immediately narrows the list of possible causes. Every murmur falls into one of two main categories based on where it sits in the cardiac cycle: systolic (between S1 and S2, when the ventricles contract) or diastolic (between S2 and the next S1, when the ventricles relax). A third category, continuous murmurs, begins in systole and extends past S2 into diastole without interruption.
Within those broad categories, you refine further by specifying early, mid, or late. A holosystolic murmur starts right at S1 and continues all the way to S2, filling the entire systolic interval. This pattern is classic for blood leaking backward through a valve that should be closed. A midsystolic (or “ejection”) murmur begins shortly after S1, reflecting blood being pushed forward through a narrowed or stiff valve. Early diastolic murmurs start immediately after S2, while late diastolic murmurs occur just before the next S1 and typically point to a narrowed valve between an atrium and ventricle.
Location: Where You Hear It Best
Each heart valve has a traditional auscultation area on the chest wall where sounds from that valve are heard most clearly:
- Aortic area: second intercostal space at the right sternal border
- Pulmonic area: second intercostal space at the left sternal border
- Tricuspid area: left lower sternal border
- Mitral area: fifth intercostal space at the left midclavicular line (the apex of the heart)
Identifying where the murmur is loudest points toward which valve is involved. You should also note whether the murmur radiates, meaning it can be heard in areas away from the point of maximum intensity. A murmur from a narrowed aortic valve classically radiates up into the neck along the carotid arteries. A murmur from a leaking mitral valve often radiates to the left axilla (armpit area). Radiation patterns are worth documenting because they add diagnostic specificity.
Intensity: The Levine Grading Scale
Murmur loudness is graded on a six-point scale originally proposed by cardiologist Samuel Levine. The grades are typically written as a fraction, such as “grade III/VI,” to show you’re using this specific system.
- Grade I: so faint it can only be heard with special effort and concentration
- Grade II: faint but immediately audible once you place the stethoscope
- Grade III: moderately loud, easy to hear
- Grade IV: very loud, accompanied by a palpable thrill (a vibration you can feel with your hand on the chest wall)
- Grade V: extremely loud, audible with just the edge of the stethoscope touching the chest
- Grade VI: so loud it can be heard with the stethoscope lifted slightly off the chest
The key dividing line is at grade IV. Any murmur at grade IV or above produces a thrill. If you can feel a vibration under your hand but call the murmur grade III, something doesn’t add up. Louder murmurs do tend to correlate with more significant pathology, but a quiet murmur does not automatically mean it’s harmless.
Quality: Pitch and Character
Quality captures what the murmur actually sounds like. Start with pitch: is it high-frequency or low-frequency? High-pitched murmurs are best heard with the diaphragm of the stethoscope pressed firmly against the skin. Low-pitched murmurs come through better with the bell held lightly.
Beyond pitch, several descriptive terms are used to characterize the sound:
- Blowing: a soft, whooshing quality. The classic example is the early diastolic murmur of a leaking aortic valve, heard best at the left lower sternal border as blood flows backward into the left ventricle.
- Harsh: a rough, grating quality. Small holes between the heart’s chambers (like a small atrial septal defect) tend to produce harsh murmurs because blood forces through a narrow opening at high velocity.
- Rumbling: a low-pitched, rolling sound. Mid-diastolic rumbles at the apex are associated with a narrowed mitral valve or conditions that mimic it.
- Musical: a tonal, almost melodic quality that stands out distinctly from the other types.
- Squeaky: less common, sometimes described in specific valve abnormalities.
These terms are subjective, and two listeners might choose different words. That’s fine. The goal is to convey the overall character so the next person reading your note can anticipate what they’ll hear.
Shape: How Intensity Changes Over Time
The shape, or configuration, describes whether the murmur gets louder, quieter, or stays the same as it progresses. Four profiles cover most murmurs:
- Crescendo: starts soft and builds in intensity. A late diastolic murmur that crescendos into S1 suggests a narrowed mitral or tricuspid valve during atrial contraction.
- Decrescendo: starts loud and fades. The blowing diastolic murmur of aortic regurgitation follows this pattern as the pressure difference between the aorta and ventricle decreases.
- Crescendo-decrescendo (diamond-shaped): builds to a peak and then fades. This is the signature shape of aortic stenosis, where blood accelerates through a narrowed valve opening and then decelerates.
- Plateau: stays at the same intensity throughout. Holosystolic murmurs from mitral or tricuspid regurgitation often have a plateau shape because the pressure gradient driving the backward flow remains relatively constant.
Putting It All Together
A complete murmur description strings these components into a single statement. For example: “A grade III/VI, harsh, crescendo-decrescendo systolic murmur heard best at the right upper sternal border, radiating to the carotids.” That one sentence tells the listener the murmur is moderately loud, rough-sounding, diamond-shaped, occurs during ventricular contraction, is loudest over the aortic area, and travels up to the neck. It paints a clear picture of aortic stenosis without ever naming the diagnosis.
A useful order to follow when documenting: timing first, then intensity (grade), quality (pitch and character), shape, location of maximum intensity, and radiation. Some clinicians vary the sequence, but covering all six components is what matters.
How Dynamic Maneuvers Refine the Description
Sometimes two murmurs sound similar, and you need an extra step to tell them apart. Certain physical maneuvers change how much blood flows through the heart, which in turn changes murmur intensity in predictable ways. Noting how a murmur responds to these maneuvers adds a powerful layer to your description.
The Valsalva maneuver (bearing down as if straining) reduces the amount of blood returning to the heart. This makes most murmurs quieter, including aortic stenosis and mitral regurgitation. The notable exception is hypertrophic obstructive cardiomyopathy (HOCM), where the murmur gets louder because less blood in the ventricle allows the obstruction to worsen.
Squatting does the opposite. It increases blood return to the heart and raises the resistance blood must push against when leaving. This makes aortic stenosis, aortic regurgitation, and mitral regurgitation louder while reducing the HOCM murmur. Isometric handgrip (sustained squeezing) similarly raises resistance and reduces murmurs from HOCM, aortic stenosis, and mitral valve prolapse.
The practical takeaway: if a systolic murmur gets louder with Valsalva and quieter with squatting, that pattern strongly suggests HOCM rather than aortic stenosis, even though both can produce crescendo-decrescendo systolic murmurs at baseline.
Innocent Versus Pathologic Murmurs
Not every murmur signals a structural problem. Innocent (also called “functional” or “benign”) murmurs are common, especially in children, and reflect normal blood flow turbulence rather than valve disease. They tend to be soft (grade I or II), systolic, and have a musical or vibratory quality. They typically occur in the midsystolic window, are heard at the left sternal border, and do not radiate. They also change with position, often getting quieter when the patient sits or stands.
Pathologic murmurs, by contrast, are more likely to be loud (grade III or above), diastolic, holosystolic, or associated with a thrill. They frequently radiate and may come with other abnormal heart sounds. Any diastolic murmur is considered pathologic until proven otherwise, because normal forward blood flow during diastole is usually silent. Recognizing these red flags in your description helps distinguish murmurs that need further workup from those that can be monitored without concern.