Anesthesia management of Mitral stenosis

1. MITRAL STENOSIS
Anesthetic considerations
Dr.Harshil Joshi
DM Cardiac Anesthesia Resident

2. Mitral Stenosis
• Mitral valve is present between LA & LV
• Normal mitral valve orifice area (MVA): 4-6cm2
• MVA <2.5cm2
leads to symptoms
• Decrease in Mitral valve orifice area leading to chronic &
fixed mechanical obstruction to LV filling is termed as MS.

3. Natural History- untreated MS
• Progressive, lifelong disease
• Usually slow & stable in the early years
• Progressive acceleration in the later years
• 20-40 year latency from rheumatic fever to symptom onset in
developed countries
• After symptoms-- additional 10 years before disabling
symptoms

4. Causes
• Rheumatic Heart disease
• SLE
• Carcinoid syndrome
• Active Infective Endocarditis
• Left atrial myxoma
• Congenital mitral stenosis
• Massive Annular Calcification

5. Rheumatic mitral stenosis
• More common in females (2/3rd
of all pts)
• Symptoms occur two decades after onset of Rheumatic fever
• Age of presentation
– Earlier in 20s-30s
– Now in 40s-50s (slower progression)
• Isolated MS in 40% cases of RHD
– Remaining 60% cases associated with other valvular
diseases- MR/AR

6. Rheumatic fever- Jones criteria
Major criteria
• Carditis
• Arthritis
• Subcutaneous nodules
• Chorea
• Erythema marginatum
Minor Criteria
Clinical
• Fever
• Arthralgia
• P/H rheumatic fever / RHD
Laboratory
• Acute phase reactants:
leucocytosis, ESR, CR
proteins
• Prolonged PR interval

7. RF - Essential criteria
• Evidence for recent streptococcal infection as indicated by
– Increased anti streptococcal antibody titers
– Positive throat cultures
– Recent scarlet fever

8. Symptoms
• Valve area > 1.5 cm2
usually does not produce
symptoms at rest
• Dyspnoea in patients with mild MS usually
precipitated by
– Exercise
– Emotional stress
– Fever, Infection
– Anaemia
– Pregnancy
– Atrial fibrillation with rapid ventricular response
– Thyrotoxicosis

9. Symptoms…
• Dyspnoea
• PND
• Orthopnea
• Palpitations
• Fatigue
• Chest pain (RVH,CAD)
• Cough
• Hemoptysis
• Atrial fibrillation
• Systemic embolism
• Pulmonary infection
• Right sided failure
– Hepatic Congestion
– Edema

10. General examination
• Mitral facies
‘Pink purple patches on the cheeks, cyanotic skin
changes from low cardiac output’
• Pulse – low volume pulse
• Blood pressure

11. Examination
Inspection
• Engorged vein in neck
Palpation:
• Tapping apex beat
• Palpable S1
• Parasternal heave
• Palpable S2
• Diastolic thrill
Auscultation:
• S1 is short, sharp , accentuated
(loud, snapping)
• S2 audible
• Opening snap after S2
• A2 to OS interval inversely
proportional to severity
• Diastolic rumble: length
proportional to severity
• In severe MS with low flow-
S1, OS & rumble may be
inaudible

12. Features of PHT
Palpation:
• Parasternal heave
• Palpable S2
Auscultation:
• ESM over pulmonary area
• SM which increases on
inspiration heard along the
left sternal border
-Functional TR
• Graham Steel murmur –
pulmonary Regurgitation

13. Complications
• Atrial dysrhythmias
• Systemic embolization (10-25%)
– Risk of embolization is related to age, presence of atrial
fibrillation, previous embolic events
• Congestive heart failure
• Pulmonary infarcts (result of severe CHF)
• Endocarditis
• Pulmonary infections

14. Normal mitral valve
• MVA > 4 cm2
(4- 6 cm2
)
• Diastolic mitral valve flow of 150- 200 ml/
sec/ diastole
• Diastolic transvalvular pressure gradient of
less than 2 mmHg

15. Classification
Mild Moderate Severe
Mean gradient (mm Hg) < 5 5- 10 > 10
Pulmonary artery systolic
pressure (mm Hg)
< 30 30- 50 > 50
Valve area (cm2
) > 1.5 1.0- 1.5 < 1.0

16.  Pre-operative Optimization
of patient
Atrial fibrillation
Sinus rhythm/control of ventricular rate
1. Digoxin (emergent IV digitalization:- loading dose
0.25mg iv over 15 minutes followed by 0.1mg every
hour till response occur or total dose of 0.5-1.0mg.
Monitor ECG, BP, CVP; HR <60bpm- Stop)
2. CCB (verapamil/diltiazem: 0.075-0.15mg/kg IV)
3. β-blocker (esmolol: 1mg IV)
4. Amiodarone (loading: 100mg IV,
infusion: 1mg/min IV for 6 hrs.
0.5mg/min for next 18 hrs)
5. Cardioversion in hemodynamic unstable patients

17. – Pulmonary HTN/Edema/RVF
1. Oxygen
2. Diuretic
Loop diuretics
High dose deleterious
Combine with vasodilator
3. Digitalis
4. Morphine (0.1mg/kg)

18. 5. Vasodilators (NTG)
Pulmonary vasodilation (↓PAP)
Start from small dose (0.5–10 μg/kg/min)
S/E: systemic hypotension
6. Nesiritide
Recombinant BNP
Arterial & venous dilatation
Controls dyspnoea in Acute heart failure
7. Myofilament calcium sensitizer
(Levosimendan)
Inodilators (↑es myocardial contractile
strength, dilatation of systemic, pulmonary &
coronary artery)

19. 8. Inotropic agents
Norepinephrine
Dopamine
Dobutamine
9. Inodilators
Amrinone
Milrinone

20. • ANAESTHETIC MANAGEMENT
medications to continue intra operatively
• Diuretics- Evaluate fluid status
Check electrolytes on day of
surgery
• Drugs to control AF ( Digoxin, beta blockers,
Amiodarone) Continue in perioperative
period
• Patients on pulmonary vasodilators
(sildenafile,bosentan)

21. • Watch serum potassium- in patients
receiving digoxin and diuretics
• Warfarin- switch to heparin perioperative for
better control.
Titrate to APTT 1.5-2 times normal
Continue post op.
• Management of anticoagulation
perioperatively should balance risks of
bleeding with the risk of thrombosis and
systemic embolization

22. Management of Anesthesia
Anesthetic goals
Heart rate/
rhythm
Sinus rhythm, control
ventricular rate (70-
90bpm)
Avoid tachycardia
Preload Normal or increased Avoid under-load/
overload
After-load Maintain normal after
load
Avoid sudden
increase/reduction in
afterload
Contractility Usually LV systolic
function: N
But may be reduced in
long history
Avoid cardio-
depressant drugs
Pulmonary HTN/RV
dysfunction
Normal oxygenation,
acid base status
Avoid hypoxia,
hypercarbia, acidosis

23. • ANAESTHETIC MANAGEMENT
• Premedication
• Adequate dose prevents anxiety and tachycardia.
While overdose cause hypoventilation &
hypotension(↑pvr &↓c.o.) exacerbate pulmonary
hypertension.
Morphine 0.1-0.2mg/kg
Clonidine 30ug iv 30 min before surgery
Small dose Benzodiazepenes can be given
( reduce dose of morphine)
• Anticholinergics- avoided as they increase heart
rate

24. Pre medication
• To decrease anxiety & any associated likelihood of adverse
circulatory responses produced by tachycardia
Class Drug Dose (mg/kg) Route
BZPs Diazepam 0.1-0.15 PO, IM
Lorazepam 0.03-0.06 PO, IM
Midazolam 0.03-0.07 IM
Opioids Morphine 0.2 IM
Meperidine 1.0-1.5 IM

25. • Monitoring
• ECG, BP, Spo2, capnography, temperature
• Invasive monitoring-
-Direct arterial pressure
-CVP- measure loading conditions and means of
transfusing inotropes/dilators
-Pulmonary artery catheter-
- Monitor Pulmonary Artery Pressure ( PAP)- useful in
PAH
- Helpful for confirming the adequacy of cardiac
function, intravascular fluid volume, ventilation, and
oxygenation.
- PCWP reflect LA pressure but not LVEDP because
of mitral stenosis.

26. 2- D ECHO2- D ECHO
Mitral valve areaMitral valve area
MV characteristics ( Wilkins score )MV characteristics ( Wilkins score )
LA – LV gradientLA – LV gradient
Mitral regurgitationMitral regurgitation
Dimensions of LA , LA clot from TEEDimensions of LA , LA clot from TEE
Pulmonary hypertensionPulmonary hypertension
Other valvular pathologyOther valvular pathology
LV functionLV function

27. • ANAESTHETIC MANAGEMENT
• Induction
• Etomidate best for hemodynamic stabilty .
• Any intravenous induction drug except
ketamine( H.R.)
• Should be double diluted and given slowly.
• Midazolam,Narcotic( morphine 0.5mg/kg or
Fentanyl 5-10 ug/kg)
• Avoid Propofol- direct and indirect effects on
ventricular preload

28. • Muscle relaxants
Vecuronium + Narcotics- dangerous
bradycardia. Hence pancuronium preferred
unless basal heart rate is high
Rocuronium- vagolytic. Hence slightly HR
and PAP↓
• Avoid atracurium- histamine release
• Benzodiazepenes (midazolam) – use
cautiously as can cause profound
vasodilatation with narcotics.

29. Non-opioid induction agents
Thiopentone Propofol Etomidate Ketamine BZP
MAP ↓ ↓ ↔ ↑ ↓
HR ↑ ↓ ↔ ↑ ↓
CO ↓ ↓ ↔ ↑ ↓
SVR ↓ ↓ ↔/↓ ↑ ↓
PVR ↔ ↔/↓ ↓ ↑ ↔
contr ↓ ↔/ ↓ ↔ ↔/↑ ↔

30. Muscle Relaxants
Pan Vec Roc Atra Miv Sch
MAP ↑ - ↑ ↓ ↓ ↓
HR ↑ - ↑ ↔ ↔ ↓
CO ↑ - ↑ ↑ ↑ -
SVR - - - ↓ ↓ -
Histamine - - - + + -

31. • Maintainence
• A balanced anesthesia that includes low
concentrations of a volatile anesthetic is desirable.
Avoid halothane- arrythmogenic
• Isoflurane(tachy cardia),Sevoflurane(ideal).
• Nitrous oxide – Increases PVR . Best avoided in PAH
• Vasodilator therapy ( NTG/ Nitroprusside 0.5-1
ug/kg/min)- desirable in severe PAH
• Intraoperative fluid replacement must be carefully
titrated
• Reversal- slowly to help ameliorate any drug-induced
tachycardia caused by the anticholinergic drug in
the mixture.

32. • Post operative management
• MV replacement-improves hemodynamics , obstruction to
LV filling resolved
• Mean gr. 4-7 mm hg across prosthetic valve remain.
• If pulmonary hypertension & rv failure – support of
choice is milrinone, dobutamine , nitricoxide & pg E1
• Inotropic support and vasodilator therapy should be
continued for prolonged ( 24-48 hrs) in patients
with severe PAH.
• May require a period of mechanical ventilation:
- avoid Pain and hypoventilation(PVR)
• Relief of postoperative pain with neuraxial opioids
useful

33. Post-operative
Management
• Monitoring
• Oxygen
• Pain relief: multimodal
including neuroaxial
opioids
• Intravenous fluids
• Anticoagulants
Complication
• Pulmonary
congestion/edema
• Thrombo-embolism
• Heart failure

34. Summary of MS
• Is a low & fixed cardiac output condition
• Stress condition like pregnancy, labour & sepsis, condition become
worst- CHF, pulmonary edema, AF
• Patients may be on diuretics, digitalis & anticoagulant therapy
• Peri-operatively these patients have to be managed as per
medications & guidelines
• Tachycardia has to be avoided at any cost
• Pulmonary vasculature resistance has to be reduced
• Preload & afterload both should be maintained

35. Summary
• Valvular heart disease poses challenge during anesthesia
• We should know pathophysiology of each valvular heart
diseases
• Most of the time, valvular heart diseases occur in combination
• Our aim is to maintain normal cardiac output & tissue
perfusion by regulating heart rate/rhythm, preload, afterload,
myocardial contractility.
• Use of regional anesthesia is not contraindicated in theses
patients, but proper patients selection & precaution are must.

36. References
• Kaplan’s Cardiac Anesthesia; 5th
edition
• Miller’s Anesthesia; 7th
edition
• Clinical Anesthesia; Barash, Cullen, Stoelting, 5th
edition
• Stoelting’s Anesthesia & Co-existing Disease; 5th
edition
• Harrison’s Internal Medicine; 17th
edition
• Wylie & Churchill- Davidson’s A Practice of Anesthesia; 7th
edition
• Clinical Anesthesia; Morgan 4th
edition

37. THANK YOU