Which of the following statements best describes innocent murmurs?

• A. Heard in the 2nd to 4th intercostal spaces with little radiation, grade 1–2, low to medium pitch, and decrease or disappear upon sitting.
• B. Radiates to the carotids and is harsh in quality.
• C. Usually associated with anemia or fever.
• D. Always indicates underlying heart disease.

Answer: (A)

Innocent murmurs are harmless, flow-related sounds that occur without underlying heart disease. They are typically soft and short, usually graded I–II, and tend to be nonradiating. A hallmark is that they are best heard at the left-sided lower chest (often described as the 2nd to 4th intercostal spaces) with a low to medium pitch, and they tend to diminish or disappear when the patient sits up or changes position. This physiologic, nonpathologic pattern helps distinguish them from murmurs due to valve disease, which often radiate to the carotids and can be harsher in quality. While flow murmurs can be associated with conditions like anemia or fever due to increased blood flow, they are not definitive of heart disease. The described features—location in the upper left chest, minimal radiation, soft grade, low-to-mid pitch, and reduction with sitting—fit an innocent murmur best.