Valvular Heart Disease Flashcards
Examples of diseases affecting the heart
Mitral stenosis
Mitral regurgitation
Aortic Stenosis
Aortic regurgitation
*Clinical presentation of mitral stenosis
Pulmonary hypertension ->
dyspnoea, pink frothy sputum, left atrial dilatation, right ventricular hypertrophy, palpitations.
Malar flush due to low CO.
Opening snap and diastolic murmur.
What causes malaria flush?
Low CO
associated with mitral stenosis due to the resulting CO2 retention and its vasodilatory effects
What is malar flush?
plum-red discolouration of the high cheeks
When listening to heart sound of patient, what would be characteristic of mitral stenosis?
Mid-diastolic murmur
Pathophysiology of mitral stenosis
Inflammation -> Mitral valve thickened/calcified obstructing normal flow from LA to LV.
Therefore LA pressure increases to maintain CO: Raised LA pressure -> LA hypertrophy and dilatation -> palpitations.
Raised LA pressure -> pulmonary hypertension -> RV hypertrophy, dilation and failure with subsequent tricuspid regurgitation.
Raised pulmonary pressure also causes the development of pulmonary capillary oedema (especially with atrial fibrillation)
Aetiology of mitral stenosis
Rheumatic valvular disease (usually Strep pyogenes) - main
Others:
Infective endocarditis (3.3%)
Mitral annular calcification (2.7%)
*Diagnostic tests of mitral stenosis?
CXR: LA enlargement, pulmonary oedema/congestion, occasionally calcified mitral valve.
ECG: AF, LA enlargement, RV hypertrophy
Echocardiography: assess mitral valve mobility, gradient and measure mitral valve area.
What is area of normal mitral valve?
4-6 cm^2
At what size do symptoms of mitral stenosis occur
When mitral valve area is less than 2 cm^2
Treatment of mitral stenosis
- Diuretics (furosemide) - for fluid overload
- Beta-blockers e.g. Atenolol and digoxin which control heart rate and thus prolong diastole for better diastolic filling
- Percutaneous mitral balloon valvotomy
- Excise segments of valve, or mitral valve replacement
Also: Infective endocarditis prophylaxis (amoxicillin?)
(Rate control + anticoagulation)
*Clinical presentation of mitral regurgitation
*Pansystolic murmur (at apex radiating to axilla)
Mid-systolic click and late systolic murmur in mitral prolapse
Deviated apex beat.
Variable haemodynamic effects:
Palpitation due to increased stroke volume
Fatigue and lethargy due to reduced CO
Right heart failure and eventual congestive cardiac failure symptoms.
Dyspnoea
What heart sound would you associate with mitral regurgitation
pan-systolic murmur
Pathophysiology of mitral regurgitation
Mitral valve fails to prevent reflux of blood. Regurgitation into the LA -> increased LA dilation and eventually pressure -> increased pulmonary pressure -> pulmonary hypertension
Progressive left atrial dilatation and right ventricular dysfunction due to pulmonary hypertension.
Progressive left ventricular volume overload leads to dilatation and progressive heart failure.
Pure volume overload due to leakage of blood into left atrium during systole
Aetiology of mitral regurgitation
Due to abnormalities of the valve leaflets, chordae tendinae, papillary muscles or left ventricle.
Most frequent cause is Myxomatous Degeneration (MVP) - weakening of chord tendinae, resulting in a floppy mitral valve that prolapses.
Dilatation of mitral valve annulus (fibrous ring attached to mitral valve leaflets). Mitral valve prolapse. Infective endocarditis. Rheumatic valvular disease. Marfan’s and Ehler-Danlos.
Papillary muscle dysfunction/rupture.
Epidemiology of mitral regurgitation
Second most common valvular condition requiring surgery
Mild physiological mitral regurgitation (MR) is seen in 80% of normal individuals
*Diagnostic test of mitral regurgitation
*Echocardiography:
• Estimation of left atrium and left ventricle size and function
• Also gives valve structure assessment
• Transoesophageal is very helpful
CXR:
• Left atrial enlargement and central pulmonary artery enlargement
ECG:
• May show left atrial enlargement, atrial fibrillation and left ventricle hypertrophy in severe MR
• But NOT diagnostic
Treatment of mitral regurgitation
Repair preferred over replacement (repair when any symptoms at rest or exercise)
Meds:
ACE-inhibitor as vasodilator (smooth muscle relaxer) e.g. ramipril or hydralazine
Beta blocker (Atenolol), calcium channel antagonist and digoxin for heart rate control of AF
Anticoagulation also in AF and flutter
Diuretics e.g. furosemide for fluid overload
*Clinical presentation of aortic stenosis
Any elderly person with chest pain, exertion dyspnoea or syncope (loss of consciousness due to lack of blood).
Slow rising carotid pulse.
Left ventricular hypertrophy -> Prominent 4th heart sound
SAD:
Syncope, angina, dyspnoea (on exertion due to HF).
Heart failure and sudden death
Heart Sounds:
-Ejection systolic murmur
-soft or absent second heart sound
(-loudness does NOT tell you anything about severity)
*What heart sound would you associate with aortic stenosis
Early systolic murmur
Pathophysiology of aortic stenosis
Aortic valve thickened/calcified obstructing normal flow.
Obstructed LV outflow -> Increased afterload -> Increased LV pressure -> Compensatory LV hypertrophy -> Relative ischaemia (of LV myocardium as hypertrophy increases blood demand) -> Angina, arrythmia and LV failure -> Reduced cardiac output.
Aetiology of aortic stenosis
Calcific degeneration:
Calcific aortic valvular disease (CAVD) - calcification of aortic valve resulting in stenosis, mainly in elderly.
(Calcification of a) Congenital bicuspid aortic valve (BAV) - has 2 cusps, not 3 due to genetic disease - most common congenital heart disease
Rheumatic valvular disease.
Epidemiology of aortic stenosis
Most common valvular condition requiring surgery.
Primarily a disease of ageing
Congenital is second most common cause.
Most common cause of valvular disease in western world.
*Diagnostic tests of aortic stenosis
Echocardiography:
- Left ventricular size & function; LV hypertrophy, dilation and ejection fraction
- Doppler derived gradient and valve area (AVA), allows for the assessment of the pressure gradient across the valve during systole.
ECG: LV hypertrophy; LA delay; LV strain pattern seen as:
Depressed ST segments and T-wave inversion in leads I, aVL, V5 and V6
CXR: LV hypertrophy; calcified aortic valve
Treatment of aortic stenosis
Rigorous dental care due to high risk of Infective Endocarditis
Aortic Valve replacement,
Transcatheter aortic valve replacement (TAVI) - percutaneous alternative for surgical replacement,
Surgical valvuloplasty or Balloon valvuloplasty also
Sequelae of aortic stenosis
Left sided HF
Sudden death