Valvular Heart Disease Flashcards
What are the most common reasons for aortic stenosis?
senile calcific: seen in 2-7% of population over 65 yrs. atherosclerotic like process
bicuspid Aortic Valve: congenital, 1-2% of population- presents with stenosis in 5th/6th decade of life - associated with coarctation, aortic root dilatation, aortic dissection, associated with aneurysm of aorta above the valve
Rheumatic Aortic stenosis
Describe the Pathophysiology of aortic stenosis?
- pressure overload of the left ventricle
- LV = hypertophic compensation
- Diastolic dysfunction ( stiff heart due to hypertophy)
- supply/demand for myocardial energetics = angina
- fixed cardiac output = syncope/presyncope on exertion
- progressive fibrosis
- irreversible myocardial dysfunction/heart failure
describe the classic ‘history’ of aortic stenosis
- Angina
- syncope
- dyspnoea
- murmur (quiet)
- may be asymptomatic
what might you include in an exam for aortic stenosis?
- blood pressure (narrow pulse pressure)
- cardiac apex = sustained heaving due to pressure
- aortic murmur radiating to carotids
- second heart sound soft in severe condition
what sort of management do we use for aortic stenosis?
- avoid strenuous exertion
- control hypertension (beta blocekers)
- control CV risk factors
- medication does NOT improve survival
- if symptomatic = requires aortic valve replacement
Describe the acute causes of aortic regurgitation
- worsening of chronic cause
- infective endocarditis
- aortic dissection
- aortic trauma
- pregnancy
Describe the difference in pathophysiology between acute aortic regurgitation and chronic aortic regurgitation
ACUTE
- abrupt large volume overload into non-compliant LV = pulmonary oedema and circulatory collapse
CHRONIC
- LV compensates- volume overload leads to hypertrophy, LV dimensions increase as does ejection fraction
- during exercise afterload reduces and is fairly well tolerated
- over time= myocardial dysfunction
what signs might we observe in Aortic Regurgitation?
- third heart sound due to abrupt blood ‘stopping’ in fixed volume LV
- murmur (diastolic) and louder with expiration- duration of murmur corresponds to severity of disease
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what sort of managmenet do we utilize in patients with aortic regurg?
ACUTE = surgical emergency
CHRONIC = if symptomatic, valve replacement
if asymptomatic= ACE inhibitors, follow up and elective surgery
Describe the pathophysiology of Mitral stenosis
- Increased LA pressure and resulting pulmonary pressures
- longstanding MS causes persistently elevated PA pressures and increased pulmonary vascular resistance (secondary pulmonary hypertension)
- eventually RV failure
- LV is “protected”
- A fib is common
Describe the symptoms of Mitral stenosis
- dyspnoea (usually only in exertion)
- orthopnea
- paroxysmal nocturnal dyspnea
- recurrent chest infections
- oedema
- palpitation
how do we treat mitral stenosis?
Medical: surveillance, anticoag, beta blockers, diuretics for congestion
surgical: percutaneous mitral balloon valvuloplasty, replacement
Describe the pathophysiology of Mitral Regurgitation
ACUTE:
- sudden volume overload in unprepared LV
- LA pressure increases = pulmonary oedema
CHRONIC
- chronic volume overload
- compensatory eccentric LV Hypertrophy
- increased Stroke volume and Left ventricular ejection fraction
- LA enlarges
CHRONIC DEcompensated
- LV function declines
- increased left ventricular end systolic volume and end diastolic pressure = pulmonary oedema
How do we treat acute and crhonic Mitral regurgitation?
ACUTE:
- diuretics, baloon pump, surgery
- antibiotics if endocarditis
CHRONIC
- surgery is sever or symptomatic
- diuretics, ACEi, rate control of Afib, anticoag,
- percutaneous mitral vavle repair
why do we prefer Mitral valve repair vs. replacement when indicated?
- repaire doesn’t mandate warfarin use, but replacement mandates lifelong warfarin use
- LV function is better preserved with repair vs. replacement
- reserve replacement for valves which are not repairable
