What is the appropriate management for a patient presenting with a collapsing pulse, potentially indicative of aortic regurgitation, and a history of hypertension, rheumatic fever, or aortic valve disease?

Management of Collapsing Pulse (Aortic Regurgitation)

A collapsing pulse indicates significant aortic regurgitation requiring immediate echocardiographic assessment to determine severity and guide urgent versus elective management, with acute severe AR representing a surgical emergency and chronic severe AR requiring intervention based on symptoms, LV dysfunction (LVEF <50-55%), or severe LV dilation (LVESD >50mm). 1

Immediate Diagnostic Approach

Clinical Assessment

• Distinguish acute from chronic AR immediately, as this determines urgency of intervention 1
• In acute severe AR, look for pulmonary edema, hypotension, cardiogenic shock, and shortened/soft diastolic murmur (not the typical long decrescendo murmur) 1
• Pulse pressure may be normal in acute AR because systolic pressure drops and diastolic pressure equilibrates rapidly with elevated LV pressure 1, 2
• In chronic AR, expect wide pulse pressure with systolic hypertension, bounding pulses, and the classic long decrescendo diastolic murmur 3

Urgent Imaging

• Obtain transthoracic echocardiography (TTE) immediately to assess AR severity, LV size/function, and identify the underlying cause 1
• If aortic dissection is suspected (acute chest/back pain, new AR), proceed directly to transesophageal echocardiography (TEE) or CT imaging—TEE has 98-100% sensitivity and 95-100% specificity for dissection 1
• TTE alone has only 60-80% sensitivity for aortic dissection and is insufficient to rule it out 1

Acute Severe Aortic Regurgitation Management

Immediate Medical Stabilization

• Initiate nitroprusside to reduce afterload and augment forward flow 1
• Consider inotropic support with dopamine or dobutamine to improve cardiac output and reduce LV end-diastolic pressure 1
• Never use intra-aortic balloon counterpulsation—it is absolutely contraindicated as it worsens regurgitant volume by augmenting diastolic aortic pressure 1
• Avoid or use beta blockers extremely cautiously (except in aortic dissection) because blocking compensatory tachycardia can precipitate cardiovascular collapse 1

Surgical Intervention

• Proceed to urgent aortic valve replacement (AVR) without delay, especially with hypotension, pulmonary edema, or low cardiac output 1
• Early surgery reduces in-hospital mortality by absolute risk reduction of 5.9% compared to medical therapy (HR 0.56, P=0.003) 1
• Do not wait for medical stabilization—death from pulmonary edema, arrhythmias, or circulatory collapse is common even with intensive medical management 1

Chronic Aortic Regurgitation Management

Severity Staging and Monitoring

Classify patients using the stage-based approach 1:

Stage C (Asymptomatic Severe AR):

• Severe AR parameters: vena contracta >0.6cm, regurgitant volume ≥60mL/beat, regurgitant fraction ≥50%, ERO ≥0.3cm², holodiastolic flow reversal in abdominal aorta 1, 4
• C1: Normal LVEF (>55%) and LVESD ≤50mm—monitor every 6-12 months 1
• C2: LVEF ≤55% OR LVESD >50mm (or indexed >25mm/m²)—proceed to surgery 1

Stage D (Symptomatic Severe AR):

• Any symptoms (dyspnea, angina, heart failure) with severe AR—immediate surgical referral regardless of LV function 1, 3

Medical Management for Chronic AR

• Control hypertension aggressively if systolic BP >140mmHg using vasodilators that do not slow heart rate 5, 2
• First-line agents: ACE inhibitors, ARBs, or dihydropyridine calcium channel blockers (nifedipine, amlodipine) 5, 2
• Avoid beta blockers—they prolong diastole, increase regurgitant volume per beat, and worsen AR 5, 2
• Vasodilator therapy may delay progression to surgery in asymptomatic patients with normal LV function, though data are inconsistent 6, 3

Surgical Timing for Chronic AR

Operate when ANY of the following occur 1, 7:

• Development of symptoms (even mild Class II symptoms carry 6.3% yearly mortality) 7
• LVEF falls to ≤50-55% (even if asymptomatic—5.8% yearly mortality risk) 1, 7
• LVESD reaches >50mm or indexed >25mm/m² (7.8% yearly mortality risk) 1, 7
• Progressive LV dilation on serial imaging 8

Do not wait for severe symptoms or marked LV dysfunction—postoperative outcomes worsen significantly once LVEF drops below these thresholds 7, 8

Surveillance Protocol

• Asymptomatic severe AR with normal LV function: Clinical and echocardiographic evaluation every 6-12 months 1
• Moderate AR: Echocardiography every 1-2 years, with more frequent imaging (every 3-6 months) if LV changes develop 5
• Mild AR: Annual clinical follow-up is sufficient 1

Critical Pitfalls to Avoid

• Do not underestimate acute AR severity—the diastolic murmur may be short and soft, and pulse pressure may be normal, leading to delayed diagnosis 1
• Do not delay surgery in acute severe AR for medical optimization—mortality remains high despite intensive care 1
• Do not use balloon counterpulsation in any form of AR—it is absolutely contraindicated 1
• Do not wait for symptoms in chronic severe AR if LV dysfunction or severe dilation develops—irreversible myocardial damage occurs 7, 8
• Do not rely on ejection fraction alone—it may remain "normal" despite contractile dysfunction due to the low afterload state of AR 3, 8
• Do not use beta blockers for blood pressure control in AR—they worsen hemodynamics 5, 2

Special Considerations

Infective Endocarditis with AR

• Proceed to surgery without delay if hemodynamic instability, heart failure, or pulmonary edema develops 1
• Early surgery reduces in-hospital mortality (HR 0.56) even in the setting of active infection 1

Aortic Dissection with AR

• Immediate surgical intervention is required for Type A dissection with AR 1
• Use beta blockers cautiously for rate control in dissection, but prioritize surgical repair over medical management 1