Sandbox/AIRSG

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

Aortic Regurgitation Resident Survival Guide Microchapters
Overview
Causes
FIRE
Diagnosis Acute Chronic
Treatment Acute Chronic Type of Valve and Anticoagulation
Do's
Don'ts

Overview

Aortic regurgitation (AR) refers to the retrograde or backward flow of blood from the aorta into the left ventricle during diastole. The presentation depends on the response and adaptability of the left ventricle to the increased diastolic volume, in chronic AR the left ventricle has adapted by dilatation of its walls. However, in acute AR, a rapid increase in the diastolic volume is not tolerated by a normal size ventricle and this could lead to cardiogenic shock. The most common causes of acute aortic regurgitation are aortic dissection and infective endocarditis and the preferred treatment in both cases surgical intervention. The most common cause of chronic AR is bicuspid aortic valve and the treatment will depend on the stage of the disease. Acute AR is a life-threatening condition and must be recognized and treated promptly.

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
• Idiopathic dilatation of the aorta
• Myxomatous degeneration
• Rheumatic fever

Click here for the complete list of causes.

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The algorithm below is based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.

Boxes in salmon color signify that an urgent management is needed.

Abbreviations: ECG: electrocardiogram; TTE: transthoracic echocardiography; TEE: transesophageal echocardiography; S1: first heart sound; P2: second heart sound, pulmonary component; S3: third heart sound

Identify cardinal findings that increase the pretest probability of aortic regurgitation Acute aortic regurgitation ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Decreased or absent S1 ❑ Increased P2 ❑ Sudden onset of dyspnea Chronic aortic regurgitation ❑ High pitched holodiastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Increases with sitting forward, expiration and handgrip ❑ Wide pulse pressure (≥ 60 mmHg) ❑ S3 ❑ Corrigan's pulse: a rapid upstroke and collapse of the carotid artery pulse

Does the patient have any of the following findings that require urgent management? ❑ Tachycardia ❑ Hypotension ❑ Altered mental status ❑ Tachypnea ❑ Oliguria ❑ Cold extremities

YES

NO

Initiate resuscitation measures: ❑ Secure airway ❑ Administer oxygen ❑ 2 wide bore IV access ❑ ECG monitor ❑ Monitor vitals continuously ❑ ICU admission Initiate medical therapy ❑ Administer nitroprusside 0.3-0.5 υg/kg/min IV (max 10 υg/kg/min), AND ❑ Administer dobutamine 0.5 υg/kg/min IV (max 20 υg/kg/min) ❑ Administer beta blockers in high suspicion of aortic dissection Do not use them for other causes as they will block the compensatory tachycardia Order urgent TTE ❑ Confirm aortic regurgitation ❑ Additional findings according to etiology: ❑ Vegetations on the leaflets ❑ Aortic root dissection In high suspicion of aortic dissection or when TTE is nondiagnostic, perform a TEE

Proceed to Complete Diagnostic Approach

What is the etiology based on clinical findings and echo?

Type A aortic dissection Diagnostic clues: ❑ Chest pain of the following characteristics: ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Syncope ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Aortic root dissection found on TTE ❑ Previous history of: ❑ Marfan syndrome ❑ Connective tissue disorder

Infective endocarditis Diagnostic clues: ❑ Persistent fever ❑ New valvular regurgitation murmur ❑ Previous blood culture positive ❑ Vegetations found on TTE ❑ High risk factors: ❑ Pre-existing cardiac abnormality ❑ Prosthetic valve ❑ Recent surgical or medical procedures ❑ Intravenous drug use ❑ Recent bacterial infection ❑ History of previous endocarditis ❑ Evaluate the modified Duke criteria (click here to see the modified Duke criteria ) ❑ Order blood cultures (if they have not been previously ordered)

❑ Immediate surgical intervention

❑ Immediate surgical intervention

Click here for aortic dissection resident survival guide

Click here for infective endocarditis resident survival guide

Diagnosis

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.

Abbreviations: BP: blood pressure; CXR: chest X-ray; ECG: electrocardiogram; LV: left ventricle; MI: myocardial infarction; TTE: transthoracic echocardiography; TEE: transesophageal echocardiography; TAVR: transcatheter aortic valve replacement; S1: first heart sound; S2: second heart sound; S3: third heart sound;

Acute Aortic Regurgitation

Characterize the symptoms: ❑ Sudden and severe dyspnea ❑ Palpitations ❑ Altered mental status ❑ Cold extremities ❑ Oliguria Symptoms suggestive of aortic dissection ❑ Chest pain ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Interscapular ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Syncope Symptoms suggestive of infective endocarditis ❑ Fever ❑ Sweats ❑ Fatigue ❑ Pleuritic chest pain ❑ Back pain ❑ Weakness ❑ Myalgias

Inquire about past medical history: ❑ Cardiac disease: ❑ Hypertension ❑ Bicuspid aortic valve ❑ Rheumatic fever ❑ Marfan syndrome ❑ Connective tissue disorder ❑ Prosthetic valves ❑ Intravenous drug use ❑ Substances used in the mixture ❑ Sharing the equipment ❑ The process of cleaning the equipment ❑ Previous infective endocarditis

Examine the patient: Vitals ❑ Temperature ❑ Fever (suggestive of infective endocarditis) ❑ Heart rate ❑ Tachycardia ❑ Blood pressure ❑ Systolic BP differential > 20 mmHg ❑ Hypertension (suggestive of aortic dissection) ❑ Hypotension (suggestive of severe regurgitation) ❑ Respiratory rate ❑ Tachypnea Cardiovascular examination ❑ Pulses ❑ Weak ❑ Jugular venous distension ❑ Cardiac auscultation ❑ Murmur ❑ Low pitched early diastolic murmur (may be absent) ❑ Best heard at the right 2nd intercostal space in aortic dissection ❑ Heart sounds ❑ Decreased or absent S1 ❑ Increased P2 (suggestive of pulmonary hypertension) ❑ S3 and S4 may be present ❑ Apical diastolic rumble Respiratory examination ❑ Rales (suggestive of pulmonary congestion) ❑ Wheeze

Order labs and tests: ❑ TTE (most important test) (Class I; Level of Evidence: B) In high suspicion of aortic dissection, perform a TEE ❑ Chest X-ray ❑ Increase cardiac silhouette (suggestive of aortic dissection) ❑ Widened mediastinum (suggestive of aortic root dilation) ❑ Pulmonary congestion (suggestive of pulmonary edema or pulmonary hypertension) ❑ ECG ❑ Nonspecific changes of ST and T wave (due to LV enlargement) ❑ Right coronary artery ischemic changes (suggestive of aortic dissection) ❑ ST elevation in II, III, aVF (Inferior MI) ❑ ST elevation in V3R and V4R (Right ventricle MI) ❑ ST depression in V1-V3 (Posterior MI) ❑ Blood culture (if suspected infective endocarditis) ❑ Cardiac enzymes (Troponin, CK-MB)

Determine the etiology of the acute aortic regurgitation

Aortic dissection Diagnostic clues: ❑ Chest pain of the following characteristics: ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Syncope ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Previous history of: ❑ Marfan syndrome ❑ Connective tissue disorder

Infective endocarditis Diagnostic clues: ❑ Persistent fever ❑ New valvular regurgitation murmur ❑ Positive blood culture ❑ Vegetations found on TTE ❑ High risk factors: ❑ Pre-existing cardiac abnormality ❑ Prosthetic valve ❑ Recent surgical or medical procedures ❑ Intravenous drug use ❑ Recent bacterial infection ❑ History of previous endocarditis ❑ Evaluate the modified Duke criteria (click here to see)

Other causes ❑ Complication of: ❑ TAVR ❑ Percutaneous aortic balloon dilation ❑ Prosthetic valve dysfunction ❑ Blunt chest trauma

Click here for aortic dissection resident survival guide

Click here for infective endocarditis resident survival guide

Chronic Aortic Regurgitation

Characterize the symptoms: ❑ Asymptomatic ❑ Dyspnea on exertion ❑ Orthopnea ❑ Paroxysmal nocturnal dyspnea ❑ Palpitations ❑ Chest pain ❑ Shortness of breath ❑ Cough ❑ Altered mental status ❑ Syncope ❑ Fatigue

Inquire about past medical history: ❑ Cardiac disease: ❑ Hypertension ❑ Bicuspid aortic valve ❑ Rheumatic fever ❑ Pulmonary disease ❑ Trauma ❑ Syphilis ❑ Ankylosing spondylitis ❑ Acromegaly ❑ Marfan syndrome ❑ Ehlers-Danlos syndrome ❑ Giant cell arteritis ❑ Takayasu's arteritis ❑ Previous cardiac surgery

Examine the patient: Vitals ❑ Heart rate: ❑ Tachycardia (suggestive of reduced stroke volume) ❑ Blood pressure: ❑ Wide pulse pressure (≥ 60 mmHg) Cardiovascular examination ❑ Pulses ❑ Corrigan's pulse: a rapid upstroke and collapse of the carotid artery pulse ❑ Cardiac auscultation ❑ Murmur ❑ High pitched holodiastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Murmur increases with sitting forward, expiration and handgrip ❑ Austin Flint murmur: a soft mid-diastolic rumble, best heard at the cardiac apex (suggestive of severe regurgitation) ❑ Heart sounds ❑ S2: decreased or absent A2; normal P2 ❑ S3 may be present (suggestive of left ventricular dysfunction) ❑ S4 may also be present ❑ Search for other characteristic signs suggestive of aortic regurgitation ❑ Traube's sign: 'pistol shot' pulse heard over the femoral artery ❑ Müller's sign: systolic pulsations of uvula ❑ de Musset's sign: head bobbing with each heart beat ❑ Hill's sign: ≥ 20 mmHg difference in popliteal and brachial systolic cuff pressures (suggestive of chronic severe AR) ❑ Quincke's sign: pulsation of the capillary bed in the nail Respiratory examination ❑ Rales (seen when congestive heart failure has developed)

Order imaging studies: ❑ TTE (most important evaluation test) (Class I; Level of Evidence: B) ❑ Chest X-ray ❑ Increase cardiac silhouette (suggestive of aortic dissection) ❑ Widened mediastinum (suggestive of aortic root dilation) ❑ Pulmonary congestion (suggestive of HF) ❑ ECG ❑ Nonspecific changes of ST and T wave (due to LV enlargement)

Classify aortic regurgitation based on the following findings on TTE: ❑ Vena contracta ❑ Jet/LVOT ❑ Regurgitant volume ❑ Regurgitant fraction ❑ Effective regurgitant orifice

Risk of AI (Stage A) ❑ No regurgitation

Mild (Stage B) ❑ Vena contracta <0.3 cm ❑ Jet/LVOT <25% ❑ Regurgitant volume <30 mL/beat ❑ Regurgitant fraction <30% ❑ Effective regurgitant orifice <0.10 cm²

Moderate (Stage B) ❑ Vena contracta 0.3-0.6 cm ❑ Jet/LVOT 25-64% ❑ Regurgitant volume 30-59 mL/beat ❑ Regurgitant fraction 30-49% ❑ Effective regurgitant orifice 0.10-0.29 cm²

Severe ❑ Vena contracta >0.6 cm ❑ Jet/LVOT ≥ 65% ❑ Regurgitant volume ≥60 mL/beat ❑ Regurgitant fraction ≥50% ❑ Effective regurgitant orifice ≥ 0.30 cm² ❑ Holodiastolic flow reversal in the proximal abdominal aorta

Asymptomatic Stage C1 ❑ Normal LVEF ❑ Mild to moderate dilatation Stage C2 ❑ LV systolic dysfunction ❑ Decreased LVEF or severe LV dilatation

Symptomatic (Stage D) ❑ Normal or decreased LV systolic function ❑ Moderate to severe LV dilatation

Treatment

Treatment of Acute Aortic Regurgitation

Shown below is an algorithm for the treatment of acute aortic regurgitation according to the 2014 AHA/ACC Guidelines for the Management of Valvular Heart Disease and the 2010 ACCF/AHA Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease

Determine the etiology and the grade of regurgitation

Infective endocarditis

Type A aortic dissection

Mild or moderate regurgitation (Stage B)

Severe regurgitation (Stage C or D)

Mild or moderate regurgitation (Stage B)

Severe regurgitation (Stage C or D)

Does the patient has any of the following? ❑ S.aureus infection ❑ Fungal infection ❑ Large vegetation

Replacement of supra-coronary ascending aorta

Aortic root replacement, OR Valve-sparing aortic root replacement

No

Yes

❑ Initiate antibiotic treatment Click here for a complete list of pathogen specific antibiotics regimens

❑ Schedule for AVR (Class I; Level of Evidence: B)

If the patient does not get better after 5-7 days: ❑ Schedule for AVR (Class I; Level of Evidence: B)

Treatment of Chronic Aortic Regurgitation

Shown below is an algorithm summarizing the treatment approach to chronic aortic regurgitation according to the 2014 AHA/ACC Guidelines on the Management of Valvular Heart Disease.

Abbreviations: TTE: transthoracic echocardiography; AVR: aortic valve replacement; CCB: calcium channel blocker; ACE: angiotensin converting enzyme; ARB: angiotensin receptor blocker

What is the stage of aortic regurgitation according to the TTE?

No regurgitation (Stage A)

Progressive regurgitation (Stage B) Mild ❑ Vena contracta <0.3 cm ❑ Jet/LVOT <25% ❑ Regurgitant volume <30 mL/beat ❑ Regurgitant fraction <30% ❑ Effective regurgitant orifice <0.10 cm² Moderate ❑ Vena contracta 0.3-0.6 cm ❑ Jet/LVOT 25-64% ❑ Regurgitant volume 30-59 mL/beat ❑ Regurgitant fraction 30-49% ❑ Effective regurgitant orifice 0.10-0.29 cm²

Severe regurgitation ❑ Vena contracta >0.6 cm ❑ Jet/LVOT ≥ 65% ❑ Regurgitant volume ≥60 mL/beat ❑ Regurgitant fraction ≥50% ❑ Effective regurgitant orifice ≥ 0.30 cm² ❑ Holodiastolic flow reversal in the proximal abdominal aorta

Is the patient symptomatic?

Asymptomatic patients ❑ Normal valve ❑ Bicuspid valve ❑ Sclerotic valve

Asymptomatic patients ❑ Control hypertension preferably with ❑ Dihydropyridine CCB, or ❑ ACE inhibitors/ARBs (Class I; Level of Evidence: B)

NO (Stage C)

YES (Stage D)

❑ No treatment is needed

❑ Perform a periodic echo (Class I; Level of Evidence:B) ❑ Every 3 -5 years for mild regurgitation ❑ Every 1 - 2 years for moderate regurgitation

Stage C1 ❑ Normal LVEF ❑ Mild to moderate dilatation

Stage C2 ❑ LV systolic dysfunction, and ❑ Decreased LVEF, or ❑ Severe LV dilatation

If patient undergoes another cardiac surgery: ❑ Schedule for AVR (Class IIa; Level of Evidence: C)

❑ Perform a periodic echocardiogram every 6 - 12 months (Class I; Level of Evidence: B) ❑ Perform an exercise stress test

❑ Schedule for AVR (Class I; Level of Evidence: B) ❑ Initiate medical therapy with ACE inhibitors/ARBs or beta blockers if patient has contraindications for surgery

Does the patient developed symptoms in the stress test?

YES

NO

❑ Initiate medical therapy with vasodilators ❑ Nifedipine 30-60 mg/day ❑ Hydralazine 10-25 mg/ q8hrs

❑ No treatment is needed

If the patient undergoes another cardiac surgery: ❑ Schedule for AVR (Class IIa; Level of Evidence: C)

Type of Valve and Discharge Anticoagulation Therapy

Abbreviations: AVR: Aortic valve replacement; INR: International normalized ratio; TAVR Tansthoracic aortic valve replacement

Determine: ❑ Age ❑ Contraindications for anticoagulation ❑ Major bleeding diathesis or coagulopathy ❑ Uncontrolled severe hypertension (systolic blood pressure >200 mmHg) ❑ Recent head trauma ❑ Platelet count < 100 000 ❑ Pregnancy ❑ Hypersensitivity to warfarin ❑ Hemorrhagic stroke

❑ Patients ≤ 60 years old (Class IIa; Level of Evidence: B), AND ❑ No contraindication for anticoagulation

❑ Patients 60 - 70 years old ❑ No contraindication for anticoagulation

❑ Patients ≥ 70 years old (Class IIa; Level of Evidence: B), OR ❑ Patients with contraindications for anticoagulation therapy (Class I; Level of Evidence: C)

Mechanical Prosthesis Avoid the use of direct thrombin inhibitors or anti-Xa agents in patients with mechanical prosthesis (Class III; Level of Evidence: B)

Either a bioprosthesic or mechanical valve is reasonable (Class IIa; Level of Evidence: B).

Bioprosthesis

Patient with risk factors†

Patient without risk factors†

Surgical AVR

TAVR

Administer for long term: ❑ Warfarin to achieve INR of 3.0 ❑ Aspirin 75-100 mg/d

Administer for long term: ❑ Warfarin to achieve INR of 2.5 ❑ Aspirin 75-100 mg/d

❑ Administer warfarin to achieve INR of 2.5 for 3 months ❑ Then administer aspirin 75-100 mg/d long term

Administer for 6 months: ❑ Clopidogrel 75 mg/d ❑ Aspirin 75-100 mg/d

†Risk factors for thromboembolism include atrial fibrillation, hypercoagulable conditions, left ventricle dysfunction, and previous thromboembolism.

Do's

❑ Perform a cardiac MRI in patients with moderate or severe AR with an inconclusive TTE to assess LV systolic function, systolic and diastolic volumes, and measurement of AR severity. (Class I; Level of Evidence: B)
❑ Exercise stress test could be useful to assess symptomatic status and functional capacity of patents with severe aortic regurgitation
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Don'ts

❑ Do not use beta blockers in aortic regurgitation that is not caused by aortic dissection as it will block the compensatory tachycardia.
❑ Do not use intra-aortic baloon counterpulsation in severe acute AI as it will increase the aortic diastolic pressure and the regurgitant volume.
❑ Do not give antibiotics to patients with known VHD before blood cultures are obtained for unexplained fever. (Class III; Level of Evidence: C)
❑ Do not give ACE inhibitors to pregnant patients with aortic regurgitation. (Class III; Level of Evidence: B)
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References

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