A heart murmur is a distinct whooshing or swishing sound heard during a physical examination, occurring between the normal “lub-dub” of the heartbeat. This noise is caused by turbulent or abnormal blood flow moving across the heart valves or through the heart chambers. While many heart murmurs are considered “innocent” or harmless, the finding must always be evaluated by a healthcare professional. A murmur can sometimes signal an underlying cardiac problem, requiring standardized tracking and communication using the International Classification of Diseases, 10th Revision (ICD-10) coding system.
The Role and Structure of ICD-10 Codes
The ICD-10 system, the International Classification of Diseases, 10th Revision, is a global standard developed by the World Health Organization (WHO) for classifying and coding health information. This system provides a common language for tracking diseases, injuries, signs, symptoms, and abnormal findings, which is crucial for epidemiology, resource allocation, and medical research. In the United States, a modified version called ICD-10-CM (Clinical Modification) is used for reporting diagnoses across all healthcare settings, including for billing and reimbursement purposes.
An ICD-10 code is an alphanumeric code that can range from three to seven characters in length. The first three characters define the general category of the condition. Subsequent characters add increasing levels of detail and specificity, allowing coders to capture anatomical sites, causes, and the severity of a condition. This structure ensures that health data is consistently recorded and understood across different providers and countries.
Identifying the ICD-10 Code for Heart Murmurs
When a healthcare provider identifies a heart murmur but has not yet determined the specific underlying cause, the finding is coded using the general category R01, which covers “Cardiac murmurs and other cardiac sounds.” This category is located within the chapter for Symptoms, Signs, and Abnormal Clinical and Laboratory Findings, confirming that a murmur is initially classified as a symptom rather than a definitive disease. Within the R01 category, distinct codes are used to specify the nature of the murmur.
The most common code used when a murmur is heard but its significance is unknown is R01.1, “Cardiac murmur, unspecified.” This code is applied when a provider notes the presence of a murmur but has not yet completed the diagnostic workup to link it to a specific cardiac disease. If the physician determines that the murmur is harmless—a frequent finding in children or during periods of rapid blood flow—the code R01.0 is used for “Benign and innocent cardiac murmurs.” This designation indicates that the sound is a functional murmur and not a sign of a structural heart problem.
A third code in this group, R01.2, is used for “Other cardiac sounds,” which serves as a catch-all for abnormal heart sounds not classified as a typical heart murmur. The choice between R01.0 and R01.1 communicates the provider’s clinical assessment. While R01.0 suggests no further investigation is necessary, R01.1 signals an unexplained finding requiring additional evaluation to rule out a pathological cause. These R01 codes are typically used as secondary codes to explain a patient’s status, not as the primary diagnosis.
Clinical Specificity and Coding for Underlying Causes
The ultimate goal of clinical practice is to move beyond the symptom code (R01.x) to a definitive diagnosis, since a murmur often manifests an underlying cardiac condition. When a complete diagnostic workup, such as an echocardiogram, reveals the structural cause of the abnormal blood flow, the coding shifts to reflect this specific disease. This transition from a sign/symptom code to a disease code is a fundamental principle of ICD-10 coding.
A pathological heart murmur is frequently caused by a disorder of one of the heart’s four valves, which can be narrowed (stenosis) or leaky (regurgitation or insufficiency). If a murmur is caused by a mitral valve problem, the code is drawn from the I34 category, which covers “Nonrheumatic mitral valve disorders.” If the cause is identified as a narrowing of the aortic valve, the code falls under the I35 category for “Nonrheumatic aortic valve disorders.”
The timing of the murmur, whether it occurs when the heart contracts (systolic) or when it relaxes (diastolic), often provides the first clue that directs the diagnostic process toward these specific valve disorders. Diastolic murmurs, for instance, are almost always pathological and suggest a serious issue like aortic or mitral stenosis, which have specific codes in the I34-I37 range. Using these disease-specific codes ensures the medical record accurately reflects the patient’s condition and justifies necessary treatment, such as medication or surgical intervention.