From the Guidelines
The most reliable bedside finding to indicate moderate to severe aortic insufficiency is a diastolic murmur, as it directly reflects the regurgitation of blood from the aorta back into the left ventricle during diastole. This murmur is typically described as a high-pitched, blowing, decrescendo sound heard best at the left sternal border with the patient leaning forward and holding their breath after expiration. The intensity of the murmur suggests significant regurgitation volume, which is a key indicator of the severity of aortic insufficiency 1.
Key Findings
- A diastolic murmur is a direct indicator of valvular incompetence, which defines aortic regurgitation
- The intensity of the murmur suggests significant regurgitation volume
- Other findings such as widened pulse pressure and rapid/collapsing pulse are associated with aortic regurgitation but are less specific and typically appear in more advanced disease
- The S4 heart sound is more commonly associated with left ventricular hypertrophy or ischemia rather than being a primary finding in aortic insufficiency
Diagnosis and Assessment
According to the European Heart Journal, the diagnosis of chronic severe AR can usually be made on the basis of the diastolic murmur, displaced LV impulse, wide pulse pressure, and characteristic peripheral findings that reflect wide pulse pressure 1. Echocardiography is also indicated to confirm the diagnosis of AR, assess the cause of AR, and provide a semiquantitative estimate of the severity of AR 1.
Severity Assessment
The severity of AR can be assessed using various parameters such as regurgitant volume, regurgitant fraction, and regurgitant orifice area, as well as indirect measures such as the rate of decline in regurgitant gradient and the degree of reversal in pulse wave velocity in the descending aorta 1. However, the diastolic murmur remains the most reliable bedside finding to indicate moderate to severe aortic insufficiency.
From the Research
Findings Indicative of Moderate to Severe Aortic Insufficiency (AI)
- The presence of an early diastolic murmur is a significant finding for ruling in AR, with a positive likelihood ratio of 8.8-32.0 for detecting mild or greater AR and 4.0-8.3 for detecting moderate or greater AR 2
- The absence of an early diastolic murmur is useful for ruling out AR, with a negative likelihood ratio of 0.2-0.3 for mild or greater AR and 0.1 for moderate or greater AR 2
- Both systolic and diastolic murmurs can be heard in most patients with moderate to severe AR, with 100% of subjects with moderate and severe AR having diastolic murmurs 3
- High grade AR, low diastolic blood pressure, high peak velocity of the AR jet, and high systolic blood pressure are significant determinants of diastolic murmur 3
Clinical Examination Findings
- Cardiologists' precision for detecting diastolic murmurs is moderate using audiotapes and good in the clinical setting 2
- Clinical examination by cardiologists is accurate for detecting AR, but not enough is known about the examinations of less-expert clinicians 2
- Systolic murmur is present in 62.5% to 100% of subjects with no to severe AR, while diastolic murmur is present in 12.5% to 100% of subjects with no to severe AR 3