Valvular Heart Disease Flashcards
Normal size of opening of mitral valve
4-6cm
Aetiology of mitral stenosis
Rheumatic heart disease
Congenital MS
Systemic conditions
Classification of mitral stenosis and pathophysiology
MV orifice<2cm
A-V pressure gradient increases LA pressure increases Pulmonary venous and capillary pressures increase PVR increases Pulmonary hypertension develops RH dilatation Left heart will be normal
Symptoms of mitral stenosis
Dyspnoea which could include pulmonary oedema
Haemoptysis due to rupture of capillaries
Systemic embolization due to enlargements of left atrium
IE
Chest pain
Hoarseness due to compression of left recurrent laryngeal nerve
Clinical examination for mitral stenosis
Red cheeks Normal pulse Prominent A wave in JVP Tapping apex beat with diastolic thrill RV heave Sound between S2 and S1
Investigations for mitral stenosis
ECG (not great but if P>0.12s)
CXR (LA enlargement)
Echocardiography (can see the narrowing)
Cardiac magnetic resonance
Treatment for mitral stenosis
Diuretics and restricted Na intake
If AF then SR restoration or ventricular rate control and anticoagulation
Aetiology of mitral regurgitation
Rheumatic heart disease Mitral valve prolapse (more common) IE Degenerative Functional due to LV and annular dilatation (the left ventricular is hypertrophic and pulls apart it's valve)
Pathophysiology of MR
Not a fixed ERO (effective regurgitant orifice) as depends on preload, afterload and LV contractility
LV will compensate
LV compensation in acute MR
ESP and ESV drop and wall tension drops
LV compensation in chronic MR
EDV increases so ESV returns to normal but eccentric LVH develops
LA compliance in MR
Can be increased, reduced or a combination
Reduced because of the pressure rise, a thickening of the atrial myocardium, increase in PVR and remodeling with PHT
Increased because of the volume enlargement but AF
Acute MR clinical signs
Breathlessness, pulmonary oedema, cardiogenic shock
Chronic MR signs
Fatigue, exhaustion (low CO), right heart failure, dyspnoea or palpitations due to AFib
Clinical examination signs of MR
Normal or reduced pulse in heart failure JVP prominent if RH failure present Brisk and hyperdynamic apex beat RV heave On auscultation, reduced S1 and split s2
Laboratory investigations for MR
ECG: LA enlargement so p>0.12s and RVH (prominent R wave in R precordial leads)
CXR: cardiomegaly, LA enlargement, calcification of mitral annulus
Treatment for mitral regurgitation
For acute, preload and afterload reduction (sodium nitroprusside, dobutamine)
For chronic, maybe LV function preservation
Normal size of aortic valve
3-4cm
Aetiology of aortic valve stenosis
Degenerative
Rheumatic
Could be bicuspid instead of tricuspid
Size of stenosis aortic valve
<1.5-2cm2
Size of stenosis aortic valve
<1.5-2cm2
Rheumatic aortic stenosis
Adhesion, fusion and retraction
Degenerative aortic stenosis
Linked to arthrosclerosis, a slow inflammatory process resulting in thickening and calcification of the cusps from bases to free margins
Effects of AS on the heart
Increased LV systolic pressure Hypertrophy Increased LVEDP PHT Increased MVO2 Myocardial ischemia LV failure
Symptoms of AS
Has a long asymptomatic phase
Chest pain, syncope/dizziness, breathlessness, heart failure
Clinical examination for AS
Small pulse volume that's slowly rising Prominent JVP if right heart failure Low BP Vigourous and sustained apex beat RV heave Late peaking on auscultation which is loud at base and radiates to carotids
Laboratory examination for AS
ECG: LV strain
CXR calcification
Echocardiography shows LV function and hypertrophy
Medical treatment for AS
Only for heart failure
Aetiology of AR at aorta
Dilated aorta
Connective tissue disorders
Aetiology of AR
Bicuspid aortic valve
Rheumatic heart disease
Endocarditis
Myxomatous degeneration
Cause of LV failure in AR
LV accommodates SV and regVol Increased pressure Hypertrophy and dilatation Increased MVO2 Myocardial ischemia
Symptoms of AR
Chronic - long asymptomatic then exertional breathlessness
Acute- poorly tolerated as wall tension can’t adapt
Clinical examination of AR
Large volume and collapsing pulse
Wide pulse pressure
Hyperdynamic, displaced apex beat
Early diastolic with decrescendo but normal S1 and S2
Lab investigations of AR
ECG: ST change as LV strain
CXR: cardiomegaly in chronic
Echocardiography: thickening,prolapse, vegetations, number of cusps, LV function, dilatation and hypertrophy
Doppler assessment of regurgitation flow
Medical treatment of AR
Vasodilators delay timing for surgery
Medical treatment of AR
Vasodilators delay timing for surgery
Causes of cardiac ischaemia
Arthrosclerosis Embolism Coronary thrombosis Aortic dissection Arteritides(inflammation) Congenital
Manifestations (results) of IHDx
Angina MI Arrythmias Chronic heart failure Sudden death
2 most dangerous types of coronary artery disease
Left main stem stenosis or 3 vessel artery disease
When would coronary artery bypass grafting surgery be done
If any CAD is symptomatic
Or if it’s LMSS or 3VDx
Patient criteria for CABG
Adequate Lung, mental, hepatic function
Ascending aorta and distal coronary artery targets OK
LV EF>20%
What vessels can be used in CABG
Reversed saphenous vein (back of leg)
Internal mammary arteries
Radial arteries
Problems from sternotomy
Wire infection
Painful wires
Sternal dehiscence
Sternal malunion
Post operative problems in cardiac surgery
Cardiac tamponade (large pericardial effusion)
Death
Stroke
Cardiac tamponade after surgery
Fluid around the heart.
Primary features are raised CVP, tachycardia, low BP
Secondary features are oliguria, needing more oxygen and metabolic acidosis
Treated by chest reopening
Long-term outcomes of CABG
50% have no further cardiac problems 10 years later
Majority of problems are minor and can be controlled with medication
5% need a repeat CABG
Main types of surgery for ages
Adult- aortic and mitral valves
Paediatrics- all four with roughly equal frequency
Three most common valve problems needing surgery in Aberdeen
Senile tricuspid AS
Bicuspid AS
Degenerative MR
Rheumatic fever
A relapsing illness related to streptococcal infections.
Causes pancarditis (whole heart inflammation) with skin and joint manifestations and Sydenham’s chorea/st Vitus dance
Treated with aspirin and bed rest
Chronic rheumatic heart disease
Gradually progressive MVDx and AVDx , worldwide most common heart problem
Causes death in pregnancy and sometimes means cardiac surgery is performed during pregnancy
Organisms that causes endocarditis
Strep viridans - subacute
Then staph. Aureus - acute
Chances of cures with different valves for endocarditis
NVE- 90% chance with ABx
PVE- 50% chance with ABx
Chances cute higher for viridans too
Indications for endocarditis surgery
Severe valvular regurgitation
Large vegetations
Persistent pyrexia
Progressive renal failure
Give IV ABx 6 weeks after surgery
Aortic stenosis
HF, angina, syncope, incidental
Easily heard murmur and loss of aortic S2
LVH, AV gradient of over 59mmHg
AVR for severe
Aortic regurgitation
HF, angina or incidental
Difficult murmur
AVR for severe especially with LV regurgitation
In severe, LV is filled with contrast after one diastolic interval during aortography
Mitral stenosis
Difficult murmur unless severe or exercised
May have presystolic accentuation
Surgery if MVA on echo is <1.5cm
Mitral regurgitation
Easy murmur
Associated with LV and LA dilatation and AF and pulmonary hypertension if severe
MVR if severe
On echo, systolic blood flow reversal in pulmonary veins (severe)
Cardiopulmonary bypass
Blood drained from RA and returned to AA
CFB machine operated by perfusionists takes over heart and lung
Systemic anticoagulation used and induced hypothermia
There will be non-pulsatile flow and max time is 12 hours. Maximum cardiac ischaemic time is 6.
Air embolism is more common in open cardiac surgery eg valve replacement than CABG
Choice of heart valve prosthesis
Biological don’t need warfarin but wear out after 15 years
Mechanical do but wear out after 40
Mitral valve repair can be possible in degenerative MR instead of replacement
Choice of heart valve prosthesis
Biological don’t need warfarin but wear out after 15 years
Mechanical do but wear out after 40
Mitral valve repair can be possible in degenerative MR instead of replacement
