Education & Fellowships
Cardiothoracic Surgery Service
LAC+USC Medical Center Student Handout
Valvular Heart Disease
The Aortic Valve
- The usual AV Area (AVA) is 2.5-3.5 Cm2.
- The aortic valve is a trileaflet structure that sits at the junction of the left ventricular outflow tract and the beginning of the aorta. The coronary ostia may be found one to two centimeters above the annulus to both the right and left. The valve has a common corridor of tissue with the mitral valve and the conduction system is located near the junction of the right and non-coronary leaflets. The usual pathology of the valve is either calcification with functional and structural stenosis or destruction of the leaflets with resultant insufficiency.
Aortic Stenosis (AS)
- The most frequent etiology for aortic valve stenosis is senile calcific stenosis, second is calcification of a congenital (bicuspid) valve , the third most frequent is rheumatic heart disease. The incidence of rheumatic disease has decreased in the last few decades but it is still prevalent.
- The pathology is that of CONCENTRIC LEFT VENTRICULAR HYPERTROPHY.
- Usual symptoms include syncope, angina, SOB b/o CHF.
- Symptoms begin with an AVA of < 1.0.
- Severe aortic stenosis with AVA < 0.7.
- Critical aortic stenosis with AVA < 0.5.
- Once symptoms begin, life expectancy is 2-3 years.
- The greatest risk is that of sudden cardiac death.
- Signs include a holosystolic murmur at the right second ICS, weak and delayed peripheral pulses.
- CXR shows minimal changes initially but cardiomegaly later.
- EKG shows LV strain pattern in the left lateral leads.
- Diagnosis is by ECHO and cardiac cath.
- If patient > 35 y/o, study the coronary arteries as well.
- Indications for surgery:
- onset of symptoms
- Progressive increase in the LVESV (LVESV: left ventricular end systolic volume)
- Procedure of choice is Aortic Valve Replacement (AVR), repair may be done rarely and with poor short term results. AVR may be accomplished with either a mechanical or bioprosthetic heart valve. The Ross procedure is also a good alternative.
Aortic Insufficiency (AI)
- Aortic root dilatation in patients >40 y/o is usually from aortic degeneration. In patients <40 y/o it is from Marfan's syndrome.
- The most frequent presentation is combined As / AI. Other etiologies include:
- congenital (bicuspid)
- ankylosing spondylitis
- Symptoms usually include SOB, palpitations, angina.
- Signs include a diastolic murmur, bobbing head, low diastolic BP.
- CXR shows signs of congestive heart failure or/and cardiomegaly (cor bovinum)
- EKG shows LV strain pattern but cardiomegaly is eccentric.
- Indications for surgery include:
- Progressive enlargement of LVESV
- Procedure is Aortic Valve Replacement (AVR).
The Mitral Valve
- The usual etiology for pathology is post-rheumatic heart disease. The next most common etiology and growing is myxomatous degeneration.
- The mitral valve area (MVA) is 4-6 Cm2.
- The mitral valve sits anatomically between the aortic valve, the circumflex artery and the coronary sinus.
Mitral Valve Stenosis (MS)
- Symptoms begin when MVA is < 1.5.
- Usual etiology is RHD.
- Symptoms are SOB, DOE, PND, all part of CHF.
- Left atrium will progressively dilate until very large, this can lead to atrial fibrillation and clot formation.
- Historically, pregnant females with MS at delivery would have cardiovascular collapse and require left thoracotomy and closed commissurotomy.
- Diagnosis is by ECHO and cardiac cath.
- Indications for surgery include symptoms, presence of transvalvular gradient by cath of > 4 mm Hg.
- Surgical correction involves:
- open commissurotomy or repair plus annular ring
- mitral valve replacement
Mitral Regurgitation (MR)
- Usual etiology is rheumatic heart disease, endocarditis, but most commonly now in the US is myxomatous degenertion and prolapse (floppy valve disease).
- Patient will present with symptoms of CHF.
- Eventually LV will become compromised because of regurgitant fraction creating a progressive cardiac dilatation.
- A systolic murmur will be heard at the apical area of the precordium.
- Indications for surgery are symptoms of CHF.
- Surgery may include:
- Valvuloplasty with implantation of annular ring
- Mitral valve replacement.
- Even with surgery, LV may be so compromised that patient may not come off CPB or continue with symptoms of CHF.
The Tricuspid Valve
- The usual tricuspid valve area is 4-6 Cm2.
- The major anatomic structure to be protected during surgery is the AV node.
- The usual pathology of the tricuspid valve includes endocarditis (IVDA), carcinoid tumors.
- The most frequent etiology for TV insufficiency is MV disease.
Tricuspid Stenosis (TS)
- Most frequent etiology is congenital, rheumatic heart disease, neoplasms.
- Symptoms are infrequent but signs are dramatic: pulstile JVD, hepatomegaly, ascites, peripheral edema.
- The right atrium is enlarged, atrial fibrillation is frequent.
- CXR shows an oligemic pulmonary vasculature.
- EKG shows atrial fibrillation and right atrial enlargment.
- Indications for surgery is the diagnosis of TS.
- Diagnosis can be made by ECHO and cardiac cath.
- Procedure of choice is open commissurotomy, may need tricuspic valve replacement (TVR).
Tricuspid Regurgitation (TR)
- The most frequent etiology for TR is physiologic as a reflection from left sided heart disease, second is endocarditis, third is neoplastic (carcinoid).
- If TR is not suspected, at time of surgery when MV is looked at, TEE may be utilized to evaluate the tricuspid valve.
- Symptoms and signs are same as for TS, however, the patient may have a pulsatile liver and less peripheral edema but more ascites.
- If TR is strictly functional and the valve leaflets are intact, an annuloplasty may solve the problem.
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