1. Valvular Heart Disease
Dr James Peerless
June 2015

2. Valvular Heart Disease
Valvular heart disease affects 5% of patients >65y in the developed world
Stenotic valvular heart disease (AS & MS) are most clinically significant.
In assessment:
assess the significance of the lesion in relation to the proposed surgery
plan according to the haemodynamic picture

3. Aortic Stenosis

4. AS - Pathophysiology AS  fixed cardiac output
unable to compensate for reduction in SVR caused by the vasodilating effect of GA
2% of >65 have severe AS
4% of >85 have severe AS
Male > female
Degenerative calcific AS
Congenital bicuspid AS (2% of ppln.)

6. Presentation History (symptoms correlate poorly with disease severity)
Chest pain
Syncope
SOB
(symptoms correlate poorly with disease severity)
Examination
Slow rising pulse
Narrow PP
Ejection sys. murmur

7. Presentation ECG CXR Echocardiography LVH with strain ?LA enlargement
remains normal until left ventricle begins to fail
calcified aortic annulus
Echocardiography

8. Grading of AS Normal Mild Moderate Severe Critical Valve Area (cm2)
3 – 4
> 1.5
1 – 1.5
< 1
< 0.6
Peak Gradient (mmHg)
< 10
< 40
< 65
> 65
Mean Gradient (mmHg)
< 5
< 25
> 40
> 70
Ao Jet Velocity (ms-1)
< 2
< 3
< 4
> 4

10. Pre-operative Care
Assessment of AS severity and LV function if possible, by echo
If surgery cannot be delayed, treat as per moderate/severe AS
Stenosis typically worsens ~0.1 cm2.yr-1

11. Peri-operative Care Monitoring Goals
To maintain haemodynamic stability
A-line
CVP (for inotropes, and fluid management)
Goals
Avoid hypotension ( myocardial hypoperfusion and ischaemia)
Maintain SVR, and adequate volume loading
Sinus rhythm
Low-normal HR
Normal electrolyte concentrations

12. Peri-operative Care
Regional anaesthesia must be approached with extreme caution
In severe cases, e.g. and including obstetrics, access to CPB should be available.

13. Post-operative Care Low threshold for HDU admission Fluid balance
Appropriate BP
Vasoconstrictor infusions may be required
Pain management

14. Mitral Stenosis

15. Mitral Stenosis Valve Area/ cm2 Normal Valve 4 – 6 Mild 1.5 – 2.5
Moderate
1.0 – 1.5
Severe
< 1

16. Mitral Stenosis Cause Pathophysiology
Normal LV, but is small and poorly filled.
Rheumatic fever, streptococcal infection
Majority are mixed valve disease
Pathophysiology
Left atrial dilatation (maintains low PAP)
Increasing LAP  pulm. HTN
Pulm. HTN  right heart hypertrophy
Secondary RH failure with PV & TV regurg.

17. Presentation History Examination Dyspnoea Haemoptysis
Recurrent bronchitis
Fatigue
Palpitations
Examination
Malar flush
Peripheral cyanosis
Tapping apex beat
Low-pitched diastolic murmur
Right heart failure

19. Presentation Investigations ECG CXR Echocardiography P mitrale AF
Valve calcification
Large LA; evidence of pulmonary congestion
Splaying of carina
Echocardiography
Gradient and valve area measurements

21. Pre-operative Care Hx, Ex, Invx
Patients frequently dyspnoeic from lung transudates
Increased work of breathing
Reduced compliance
Poor functional capacity patients (<4METs) should be considered for MV replacement

22. Peri-operative Care Relatively fixed cardiac output, similar to AS.
LV filling is optimised with a slow HR
Monitor CVP, treat arrhythmias aggressively.
Regional anaesthesia may be very hazardous.
Risk of pulm. oedema
Large boluses, head-down position
Uterine contractions

23. Peri-operative Care Goals Low-normal HR Maintain Sinus rhythm
Adequate preload
High-normal SVR
Avoid increasing PVR (pH, PaO2, PaCO2)

24. MCQs

25. MCQs In assessing severity of aortic stenosis:
The pressure gradient across the valve is the most accurate method.
Angiography is not always required.
Exercise tolerance is a good measure of severity.
The pressure gradient measured at angiography will be higher than that found on the echocardiogram.
The pressure gradient severity tends to be over estimated in pregnancy.

26. MCQs
Important factors in the intraoperative care of the patient with aortic stenosis include:
Avoiding hypotension.
Maintaining systemic vascular resistance.
Avoiding tachycardias.
Never using regional anaesthesia.
Avoiding intubation.

27. MCQs When considering the aetiology of aortic stenosis:
Aortic sclerosis is a benign variant.
Stenosis is common without calcification.
Bicuspid valves are more common in younger patients.
Rheumatic disease is a common cause of isolated aortic stenosis.
Bicuspid valves are best seen on echo in diastole.

28. Reference CEACCP 12(3) CEACCP 5(1)