VALVULAR HEART DISEASEAORTIC VALVEBackground • Trileaflet structure • Usual pathology is either: o Calcification with functional and structural stenosis or o Destruction of the leaflets with resultant insufficiencyAortic Stenosis (AS) • Causes 1. Senile calcific stenosis 2. Calcification of a congenital (bicuspid) valve 3. Rheumatic heart disease (secondary to RFi) • The pathology is that of CONCENTRIC LEFT VENTRICULAR HYPERTROPHY due to ventricular dilatation as a result of outflow obstruction • Symptoms include 1. SOB 2. Angina 3. Syncope 4. Those of CHF – orthopnoea, PND, oedema • Signs include a 1. Holosystolic murmur at the right second ICS radiating to the carotids 2. 3. Weak and delayed peripheral pulses • CXR shows minimal changes initially but cardiomegaly later. • Diagnosis is by ECHO and if +ve then cardiac catheterisation (inc pressure across valve) • Indications for surgery: 1. Symptoms 2. Increase in 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. Prognosis poor – life expectancy 2-3 years, the greatest risk is that of sudden cardiac death.
Aortic Regurgitation / Insufficiency (AI) • Casues include (>40) aortic degeneration, (<40 y/o) Marfans syndrome. • Most frequently presents in combination with Aortic Stenosis. Other etiologies incl: o endocarditis o aneurysm o congenital (bicuspid) o luetic o traumatic o rheumatic o atherosclerotic o ankylosing spondylitis o dissection o iatrogenic • Symptoms usually include: o SOB o Palpitations o Angina. • Signs include: o Diastolic murmur o Bobbing head o Wide pulse pressure (collapsing pulse) o Slow rising pulse • CXR shows signs of congestive heart failure or/and cardiomegaly (cor bovinum) • Indications for surgery include: 1.Symptoms 2.Increase end systolic volume • Procedure is Aortic Valve Replacement (AVR).The Mitral ValveBackground • The usual etiology for pathology is post-rheumatic heart disease. The next most common etiology and growing is myxomatous degeneration. • The mitral valve sits anatomically between the aortic valve, the circumflex artery and the coronary sinus.
Mitral Valve Stenosis (MS) • Usual etiology is RHD. • Symptoms are: 1. SOB 2. Angina 3. PND, orthopnoea, oedema, syncope - 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: 1. open commissurotomy or repair plus annular ring 2. mitral valve replacementMitral 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 apex radiating to axilla • Indications for surgery are symptoms of CHF. • Surgery may include: 1. Valvuloplasty with implantation of annular ring 2. Mitral valve replacement. • Even with surgery, LV may be so compromised that patient may not come off CPB or continue with symptoms of CHF.
i Rheumatic Fever – condition affecting children aged 5-15. It follows Group A Streptococcal pharangeal infection.Due to antibody-mediated autoimmune where antibodies against the bacteria cross react to cause multi-organ failure,particularly pancarditis and rheumatism. Pancarditis may cause valvular damage that predisposes to bacterialendocarditis later in life.