Sandbox/AIRSG

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]

Overview

Aortic insufficiency refers to the retrograde or backward flow of blood from the aorta into the left ventricle during diastole.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Aortic dissection
• Infective endocarditis

Common Causes

• Bicuspid aortic valve
• Senile or degenerative calcific aortic valve disease
• Hypertension
• Idiopthic dialation of the aorta
• Myxomatous degeneration
• Rheumatic fever

Management

Acute aortic insufficiency

Shown below is an algorithm summarizing the approach to acute aortic insufficiency (AI)

Abbreviations: BP: blood pressure; CXR: chest X-ray; ECG: electrocardiogram; LV: left ventricle

Characterize the symptoms: ❑ Sudden and severe dyspnea ❑ Chest pain ❑ Palpitations

Inquire about past medical history: ❑ Previously healthy ❑ Cardiac disease: ❑ Hypertension ❑ Bicuspid aortic valve ❑ Rheumatic fever ❑ Pulmonary disease

Examine the patient: Vitals ❑ Heart rate: tachycardia may be present to compensate for a reduced stroke volume ❑ Blood pressure: wide pulse pressure (systolic BP - diastolic BP ≥ 60 mmHg) Cardiovascular ❑ Pulses ❑ Corrigan's pulse:A rapid upstroke and collapse of the carotid artery pulse ❑ Cardiac auscultation ❑ Early diastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Murmur increases with: sitting forward, expiration, handgrip ❑ An S3 gallop may be present (suggestive of left ventricular dysfunction) ❑ Austin Flint murmur: a soft mid-diastolic rumble, best heard at the cardiac apex ❑ Traube's sign: Systolic and diastolic murmurs described as 'pistol shots' heard over the femoral artery when it is gradually compressed ❑ Search for other signs suggestive of aortic insufficiency ❑ Müller's sign: systolic pulsations of uvula ❑ de Musset's sign: head bobbing with each heart beat ❑ Hill's sign: A ≥ 20 mmHg difference in popliteal and brachial systolic cuff pressures, seen in chronic severe AR. Considered to be an artifact of sphygmomanometric lower limb pressure measurement ❑ Quincke's sign: Pulsation of the capillary bed in the nail Respiratory ❑ Pulmonary auscultation: search for rales (seen when congestive heart failure has developed)

Order imaging studies: ❑ Order an echocardiography, assess: ❑ Valve morphology ❑ Pressure gradient ❑ Aortic valve area ❑ Ejection fraction ❑ LV wall thickness and motility ❑ Order a CXR ❑ For acute AI, a CXR might be normal ❑ Increase cardiac silhouette (if the etiology is aortic dissection) ❑ Widened mediastinum (if the etiology is aortic root dilation) ❑ Pulmonary congestion (suggestive of HF) ❑ Order a ECG ❑ Might see nonspecific changes of ST and T wave (due to LV enlargement) ❑ If aortic dissection is the cause, the right coronary artery may be compromised and you may see ischemic changes in the territory of the right coronary artery

Treatment ❑ The use of nitroprusside and inotropic agents (such as: dopamine and dobutamine) help reduce the LV end-diastolic pressure before surgery ❑ Avoid the use of beta blockers because may block compensating tachycardia

Infective endocarditis

Aortic dissection

Mild or moderate

Severe

❑ Urgent surgical intervention ❑ Aortic valve replacement ❑ Intra-aortic balloon counterpulsation is contraindicated

Antibiotic treatment A complete list of pathogen specific antibiotics regimens with appropriate dosages and duration of treatment is available here

Chronic aortic insufficiency

Shown below is an algorithm summarizing the approach to chronic aortic insufficiency

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Do's

❑

Don'ts

❑ Do not use beta blockers in AI of causes other than AD as it will block the compensation tachycardia. ❑ Do not use intra-aortic baloon counterpulsation in severe acute AI as it will increase the aortic diastolic pressure and the regurgitant volume.

References

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