What are the clinical signs of aortic regurgitation (AR) and how can they be demonstrated step by step in a physical examination?

Clinical Signs of Aortic Regurgitation and Step-by-Step Physical Examination

The diagnosis of chronic severe AR can 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

Key Distinguishing Features: Acute vs. Chronic AR

Peripheral signs are attenuated in acute AR, which contrasts with poor functional tolerance. 1 In acute AR, pulse pressure may not be increased because systolic pressure is reduced and diastolic pressure equilibrates rapidly with elevated left ventricular diastolic pressure. 2 Conversely, chronic AR produces exaggerated arterial pulsations and low diastolic pressure, representing the first and main clinical signs for quantifying severity. 1

Step-by-Step Physical Examination

Step 1: Auscultation for the Diastolic Murmur

• Listen for a high-pitched, blowing diastolic murmur beginning immediately after the aortic component of S2, best heard along the left sternal border with the patient sitting up and leaning forward in full expiration. 1
• Assess murmur location: When the diastolic murmur is louder in the third and fourth right intercostal spaces than in the third and fourth left intercostal spaces, the AR likely results from aortic root dilatation rather than from a deformity of the leaflets alone. 1
• Listen for an Austin-Flint rumble (a low-pitched mid-to-late diastolic rumble at the apex), which is a specific finding for severe AR. 1
• Assess for a third heart sound (S3), often heard as a manifestation of the volume load and not necessarily an indication of heart failure. 1

Step 2: Palpate the Apical Impulse

• Locate the point of maximal impulse (PMI): In chronic severe AR, the LV impulse is displaced laterally and inferiorly due to LV dilation. 1
• Assess the character: The impulse is typically hyperdynamic and sustained, reflecting the increased stroke volume. 3

Step 3: Measure Blood Pressure and Assess Pulse Pressure

• Measure systolic and diastolic blood pressure: Volume overload from significant AR leads to increased total stroke volume, resulting in systolic hypertension. 2 Diastolic blood pressure falls because blood regurgitates from the aorta back into the left ventricle throughout diastole. 2
• Calculate pulse pressure: Wide pulse pressure (systolic minus diastolic >60 mmHg) is characteristic of chronic severe AR. 1, 3

Step 4: Examine Peripheral Arterial Pulsations

The following peripheral signs reflect the wide pulse pressure and are best demonstrated in chronic severe AR:

• Corrigan's pulse (water-hammer pulse): Palpate the radial artery with the patient's arm elevated above the head. A bounding, rapidly rising and collapsing pulse indicates severe AR. 3
• de Musset's sign: Observe for head bobbing with each heartbeat while the patient is sitting upright. 3
• Quincke's sign: Apply gentle pressure to the nail bed and observe for visible capillary pulsations (alternating redness and pallor). 3
• Traube's sign (pistol-shot sounds): Auscultate over the femoral artery to hear sharp systolic sounds. 3
• Duroziez's sign: Apply gradual pressure with the stethoscope over the femoral artery until a systolic murmur is heard, then apply slightly more pressure to elicit a diastolic murmur. 3
• Hill's sign: Measure blood pressure in the leg (popliteal artery) and compare to arm blood pressure. A difference >20 mmHg (leg systolic pressure higher) suggests severe AR. 3

Step 5: Assess for Signs of Heart Failure

• Inspect for jugular venous distension in acute severe AR, which may indicate elevated right-sided pressures from pulmonary edema. 3
• Auscultate the lungs for crackles indicating pulmonary edema, particularly in acute AR. 3
• Assess for peripheral edema in advanced cases with biventricular failure. 3

Critical Clinical Pitfalls

In acute severe AR, the classic peripheral signs are absent or minimal because the left ventricle has not had time to dilate and the pulse pressure may be normal or only slightly widened. 1, 2 This can lead to underestimation of severity. Instead, acute AR presents with severe pulmonary edema, hypotension, and tachycardia requiring emergency intervention. 2, 4, 3

A third heart sound does not necessarily indicate heart failure in AR—it is often simply a manifestation of the volume load. 1 Do not mistake this for decompensation without additional supporting evidence.

Peripheral signs may be less prominent in patients with reduced stroke volume due to LV systolic dysfunction or concurrent conditions that reduce cardiac output. 1 Always integrate physical findings with echocardiographic assessment for definitive severity grading.