Aortic Regurgitation

🫀 Aortic Regurgitation (AR, “Aortic Incompetence”) = backward flow of blood from the aorta into the LV during diastole due to valve malcoaptation. ➡️ Produces LV volume overload, eccentric hypertrophy, and progressive dilatation. ⚡ Chronic AR develops insidiously, whereas acute AR is catastrophic (flash pulmonary oedema + cardiogenic shock).

📖 About

• Prevalence lower than AS but important in younger patients and those with connective tissue disease.
• Pathophysiology: volume overload → eccentric LV hypertrophy → progressive dilatation → eventual systolic dysfunction + heart failure.
• In severe AR, the regurgitant jet can impair coronary perfusion → exertional angina even with normal coronaries.

🫀 Anatomy

• Normal valve: 3 cusps (left coronary, right coronary, non-coronary).
• Sinuses of Valsalva ensure coronary filling in diastole.
• Effective cusp coaptation during diastole prevents regurgitation.

🧬 Aetiology

• Valve leaflet pathology OR aortic root dilatation → incomplete closure.
• Acute AR: LV has no time to adapt → pulmonary oedema + shock.
• Chronic AR: LV adapts with eccentric hypertrophy but decompensates over time.

⚠️ Causes

🩺 Clinical Features

• Acute AR: Severe dyspnoea, hypotension, flash pulmonary oedema, shock.
• Chronic AR: Asymptomatic for years → then exertional dyspnoea, orthopnoea, palpitations, angina, heart failure.
• Murmur: High-pitched, early diastolic “blowing” murmur, left sternal edge, louder on sitting forward in expiration.
• Pulse: Wide pulse pressure; collapsing “water-hammer” (Corrigan’s) pulse.

👨‍🏫 Eponymous Signs

• Austin Flint: Mid-diastolic rumble (regurgitant jet hits mitral leaflet).
• Corrigan: Bounding “water hammer” pulse.
• Quincke: Capillary pulsations in nailbed.
• De Musset: Head bobbing with each beat.
• Traube: “Pistol shot” femoral sounds.
• Hill’s Sign: Leg systolic > arm by >20 mmHg (severe if >60).

🧪 Investigations

• Bloods: FBC, CRP, blood cultures (if IE suspected).
• CXR: Cardiomegaly, LV dilation, ± dilated ascending aorta.
• ECG: LVH ± strain, conduction delay, ischaemia.
• Echocardiography: Key for severity grading, LV function, aortic root assessment.
• Cardiac MRI: Best for regurgitant volume & root dimensions.
• Cardiac catheterisation: Coronary anatomy pre-surgery.

⚡ Complications

• Progressive LV failure & pulmonary oedema.
• Acute decompensation (endocarditis/dissection).
• Aortic aneurysm or rupture (root disease).
• Sudden death (arrhythmia, shock).

💊 Management

• 👀 Medical: – Vasodilators (ACEi, nifedipine, hydralazine) to reduce afterload. – Diuretics for symptomatic relief. – Avoid β-blockers in acute AR (slows HR → worsens regurgitation). – Serial echo surveillance for LV function (EF, LVEDD, LVESD).
• 🔪 SAVR (surgical valve replacement): Definitive. Indications: any symptomatic severe AR; asymptomatic with EF <50%, LVESD ≥50 mm, or LVEDD ≥70 mm.
• 🩻 TAVI/TAVR: Not yet standard for isolated AR, but emerging role in high-risk cases.
• 🚨 Emergency surgery: Acute severe AR (endocarditis or dissection).

✂️ Indications for Surgery (Key Rules)

• Any symptomatic severe AR.
• Asymptomatic with LVEF <50%.
• Severe AR + LVESD ≥50 mm (“rule of 50”).
• Marfan/CTD with root dilatation >50 mm.

📊 Prognosis

• Asymptomatic + normal LV → excellent prognosis with monitoring.
• Once symptomatic or LV dysfunction develops → poor outlook unless surgically corrected.
• Timely valve replacement restores near-normal life expectancy in most.

📚 References

• 2017 ESC/EACTS Guidelines
• AHA/ACC Guidelines 2020
• Otto CM, NEJM 2020: “Aortic Regurgitation and Its Management.”