Thursday, April 15, 2010

April 15th - MHH - Aortic Insufficiency

Today at MHH a patient with endocarditis and severe Aortic Insufficiency was presented.  What follows is a quick board-relevant focus on Aortic Insufficiency.  One must think of the disease in the context of whether the AI is acute or chronic.

The more common causes of Chronic Aortic Insufficiency/Regurgitation are:
Bicuspid Aortic Valve
Aortic Dissection

Infective Endocarditis
Calcific Disease of the Aorta/Myxomatous Degeneration
Marfan Syndrome
Rheumatic Heart Disease
Other Rheumatic Conditions (i.e. Rheumatoid Arthritis, Anklyosing Spondylitis, Reactive Arthritis)

Acute AI is usually causes by one of the following:
Infective Endocarditis
Trauma/Dissection of the Ascending Aorta

Depend somewhat on whether the patient has acute or chronic Aortic Insufficiency.
Acute AI usually presents with sudden onset of pulmonary edema and dyspnea
Chronic AI usually presents with progressive symptoms of congestive heart failure. 
Also - keep in mind the symptoms associated with the cause of AI (i.e. fever with endocarditis)
Physical Exam Findings
Patients will present with symptoms of cardiogenic shock - Tachycardia is common.  Look for Pulsus Paradoxus.  May have difference in BP between both arms due to dissection.  The murmur is a very soft  diastolic murmur at the LUSB (or it can he heard at the RUSB with aortic dissection).  The murmur is actually infrequently heard since the equilibrium of pressures occurs quickly. 

Patients with have a widened pulse pressure (Systolic - Diastolic < 100). S1 is soft or sometimes absent.  A Decresendo murmur at the LUSB is common (like acute, this murmur may may be at the RUSB with aortic dissection). A concurrent S3 is commonly heard. 
Multiple other Physical Exam Findings can be present due to the wide pulse pressure - Muller Sign (uvular pulsation), De Musset Sign (Head bobbing in synchrony with systole), Traube sign (Pistol Shot Femoral Murmur), Durosiez Sign (Femoral Mumur heard with compression), Corrigan Pulse (Rapid Upstoke when quick collapse), Becker's Sign (Retinal Pulsations), Quincke Pulse (capillary pulsations)

Should include an EKG (may show Left axis and/or LVH), CXR (cardiomegaly, interstitial pulmonary edema, wide mediastinum?) and TTE.  Perform a CT or TEE if suspecting dissection. Most patients should have a serum RPR/VDRL sent.

Acute Aortic Insufficiency will usually need emergent valve replacement. In the meantime, IV nitroprusside or nitroglycerin can be used for preload reduction.  Lasix for volume overload.  Supportive care with dobutamine should be administered for cardiogenic shock.  DO NOT Place an intra-aortic balloon pump!

Medications (i.e. vasodilators such as ACEI, nifedipine or hydralazine) can be given to:
1- Reduce symptoms
2- Patients that have Hypertension
3- Patients with Severe AI that may be asymptomatic, but have LV dilatation

Surgery (AV Replacement) is indicated for:
1- Symptomatic patients that have severe AI regardless of LVEF
2- Asymptomatic patients with severe AI and LVEF <50%
3 -Chronic severe AR when undergoing other cardiac surgery (i.e. CABG)

The most important determinant factor is LVEF.
In patients without  symptoms and normal LVEF, an echo is required every 2-3 years
In patients with symptoms or decreased LVEF, an echo is needed every 6-12 months

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