Mitral stenosis in pregnancy- pathophysiology & anaesthetic management

1. Mitral Stenosis in
Pregnancy: Anesthetic
Consideration
Dr. Souvik Maitra MD, DNB, EDIC
Asst. Prof
AIIMS, New Delhi
SGPGI- PG ARC- 2019

2. “Mitral stenosis may be concealed under a quarter of a
dollar. It is the most difficult of all heart diseases to
diagnose.”
- Sir William Osler
SGPGI- PG ARC-

3. Chief Complains
• 27y female, G2 P1, village dweller, presented at 39
week of amenorrhea with progressive shortness of
breath and palpitation for last 4 months
• Scheduled for elective LSCS
SGPGI- PG ARC-

4. HoPI
• Shortness of breath- insidious in onset at around 22 wk of
amenorrhea, gradually progressing, without any seasonal variation,
initially exertional, now patient c/o SOB with ordinary activity.
• Palpitation- Occasional, increased with activity
• No h/o hemoptysis
• No h/o similar illness in the past
• No history suggestive of acute rheumatic fever in the past
SGPGI- PG ARC-

5. Physical Examination
• Built & nutrition- average
• BMI 22
• BP 100/70, low volume regular pulse, PR 86/min
• Bi pedal edema +
• Raised JVP
• Right parasternal heave +
• S1- loud, P2- loud
• Mid- diastolic murmur in the mitral area
• PA- 38 week of gestation
SGPGI- PG ARC-

6. What is the clinical diagnosis?
•27y female at 39 week gestation with mitral
stenosis with pulmonary hypertension in sinus
rhythm.
SGPGI- PG ARC-

7. How will you confirm diagnosis?
• 2D Echocardiography with Doppler
• Valve area (normal 4-6 cm2)
• Transvalvular pressure gradient
• LA dimension
• PA pressure
• RV function
• Presence of LA clot
• Any other valvular lesion
SGPGI- PG ARC-

8. Assessment of severity
How mitral stenosis is classified?
SGPGI- PG ARC-

9. Clinical staging of MS
ACC/ AHA 2014
What are the stages of MS?
SGPGI- PG ARC-

10. How to classify dyspnea? NYHA Classification
• Class I - No symptoms and no limitation in ordinary physical activity,
e.g. shortness of breath when walking, climbing stairs etc.
• Class II - Mild symptoms (mild shortness of breath and/or angina) and
slight limitation during ordinary activity.
• Class III - Marked limitation in activity due to symptoms, even during
less-than-ordinary activity, e.g. walking short distances (20- 100
m).Comfortable only at rest.
• Class IV - Severe limitations. Experiences symptoms even while at
rest. Mostly bedbound patients.
SGPGI- PG ARC- 2019
SGPGI- PG ARC-

11. Final diagnosis
• 27y old term pregnant woman at 39 week of gestation
with singleton live fetus with severe mitral stenosis
(valve area 0.9 cm2), moderate pulmonary
hypertension (PA pressure 40 mm Hg) , in sinus
rhythm currently NYHA III scheduled for elective LSCS.
SGPGI- PG ARC-

12. What are the causes of MS?
• Rheumatic heart disease
• LA myxoma
• Congenital
• IE with large vegetations
• SLE, RA
• Mitral annular calcification
~50% of all rheumatic MS patients don’t have a history of rheumatic
fever in childhood.
SGPGI- PG ARC-

13. Epidemiology
• Isolated MS- 40% of all RHD
• MS with MR- 40% of all RHD
• Rest 20% are multivalvular lesion
• Onset of symptoms- 4th decades of life (in Western
countries)
• Usually 2nd or 3rd decades- in India
SGPGI- PG ARC-

14. Alteration in CVS examination in pregnancy
• JVP- Normal/ raised
• Carotid pulse- Normal volume
• Peripheral pulse- Well filled
• Apex beat- Crisp, displaced superiorly, laterally
• S1- Loud, widely split (early closure of mitral valve)
• S2- unchanged
• S3- May be heard
• RV pulsation may be palpable in thin build women
• Newmurmursareheardinmorethan90%ofpregnantwomen
SGPGI- PG ARC-

15. Mitral Stenosis: Clinical features
• Progressive dyspnea
• Palpitation
• Fatigue/ syncope
• Embolism- Stroke/ AMI
• Hemoptysis
• Persistent cough
• Left RLN palsy
• Edema/ ascites/ hepatomegaly
SGPGI- PG ARC-
Ortner Syndrome

16. What are the findings in general survey in
patients with MS?
•Malar flush- ‘mitral facies’
•BP- Usually low normal
•Peripheral pulse- low volume/ irregularly irregular
•Pedal edema - (?RVF/ ? normal in pregnancy)
•Build & nutrition- May be under-nurished
SGPGI- PG ARC-
Uncommon in Indian
patients

17. What are the classic findings in CVS
examination: Inspection
• Raised JVP
• Visible thrill in the mitral area- may be seen in thin
built patients
SGPGI- PG ARC-

18. •Tapping apex beat
•Right parasternal heave
•Palpable P2
•Palpable diastolic thrill in mitral area
What are the classic findings in CVS
examination: Palpation
SGPGI- PG ARC-

19. •S1- sharp, short & accentuated
•Low pitched, mid- diastolic rumbling
murmur in the mitral area with
presystolic accentuation
•OS- high pitched, just after S2
•Loud, narrow split P2
What are the classic findings in CVS
examination: Auscultation
SGPGI- PG ARC-

20. Why there is pre systolic accentuation?
“Atrial Kick”
Increased flow across
MV at end-diastole
Accentuation of
murmur before systole
Patients must be on sinus rhythm
SGPGI- PG ARC-

21. How the auscultatory findings change with severity?
SGPGI- PG ARC-
Severe MS
Higher pressure gradient
between LA & LV
Early opening of MV

22. What are the D/D of mid- diastolic murmur?
Mitral stenosis
Tricuspid stenosis (rarely associated with rheumatic MS)
ASD with increased flow across tricuspid valve
Ball- valve LA thrombus
LA myxoma
MR causing increased flow in MV
Austin flint murmur
SGPGI- PG ARC-

23. What happens to the JVP waves in MS?
• Large a- wave when RA pressure is elevated
• Loss of a- wave in AF
• Large v wave or c-v wave when there is TR
SGPGI- PG ARC-

24. What are the typical ECG features in MS?
 Bifid P wave- ‘P mitrale’
 RAD
 RVH
 AF
Second half of ‘P” wave may be taller
Negative 2nd half P in V1
QRS is POSITIVE (dominant R wave) in Lead II, Lead III and aVF
QRS is NEGATIVE (dominant S wave) in Lead I
1. RAD 2. Dominant R wave in V 1 3. Dominant S wave in V5/V6
4. QRS duration <120 ms
SGPGI- PG ARC-

25. What are the ECG features in Afib?
• Irregularly irregular rhythm.
• No P waves.
• Absence of an isoelectric
baseline.
• Variable ventricular rate.
• QRS complexes usually < 120
ms
• Fibrillatory waves may be
present and either fine
(amplitude < 0.5mm) or coarse
(amplitude >0.5mm).
SGPGI- PG ARC-

26. How will assess cardiovascular risk in this
patient?
SGPGI- PG ARC-

27. What is the WHO classification of maternal cardiac
diseases?
SGPGI- PG ARC-

28. What are the pathological changes in mitral valve?
SGPGI- PG ARC-

29. SGPGI- PG ARC-
SGPGI- PG ARC-

30. SGPGI- PG ARC-

31. What is shape of PV curve in MS?
SGPGI- PG ARC-

32. How mitral stenosis is different in
pregnancy?
SGPGI- PG ARC-

33. What are the cardiovascular change in pregnancy?
• Cardiac output increases up to 50%
• Stroke volume increases 20- 30%
• Heart rate increased by 10- 15%
• Blood volume increases by 40- 45%
• SVR decreases throughout pregnancy ~5-10%
• Mean systemic filling pressure increases
SGPGI- PG ARC-

34. Why parturient with MS decompensates?
SGPGI- PG ARC- 2019
SGPGI- PG ARC-

35. SGPGI- PG ARC-
SGPGI- PG ARC-

36. MS & pregnancy outcome
• 67% pregnant women in severe MS develop
significant cardiac events
• IUGR/ IUFD- around 40% untreated cases
• Pregnant women with MVA<1.5 cm2 usually
become symptomatic- even if they are
asymptomatic before pregnancy
Usually NYHA status degrades one stage in pregnancy
SGPGI- PG ARC-

37. Principles of medical management
• Anticoagulation
• Ventricular rate control
• Maintenance of sinus rhythm
• Diuresis
• Bed rest- particularly important in pregnancy
SGPGI- PG ARC-

38. Anticoagulation
Anticoagulation with VKA in MS with
AF (paroxysmal/ persistent/ permanent)
LA thrombus
Prior embolic/ thrombotic events
SGPGI- PG ARC-

39. Anticoagulation in Pregnancy
• SC/IV heparin for up to 12 weeks antepartum (aPTT
1.5–2.5-times of normal)
• Warfarin from 12 to 36 weeks (maintain INR 2.5–3.0)
• SC/IV heparin after 36 weeks
• LMWH is preferred over UFH
• Anti factor X-a level monitoring is recommended in
pregnancy
SGPGI- PG ARC-

40. How safe are the anticoagulants in pregnancy?
• Warfarin- Risk of embryopathy, miscarriage & hemorrhage
C/I in first & third trimester
UFH/ LMWH- does not cross placenta
Higher dose of UFH/LMWH required
UFH to be discontinued at least 6h before LSCS/ induction of labor
LMWH to be discontinued 12h before LSCS/induction of labor
 Higher plasma volume
 Higher renal clearance
 Metabolism by placental
heparinase
SGPGI- PG ARC-

41. Rate & rhythm control in pregnancy
• Beta blocker- Metoprolol/ Atenolol- ? Fetal growth
restriction
• Calcium channel blocker- Verapamil may be used
• Digoxin- unreliable effects in pregnancy
SGPGI- PG ARC-

42. Diuretics in pregnancy
• Furosemide, bumetanide, hydrochlorothiazide- can be
used
• Maternal hypovolemia to be avoided- risk of low
cardiac output
• Oligohydramnios & fetal dys-electrolytemia can occur
The BMJ 2018
SGPGI- PG ARC-

43. MS with AF with unstable hemodynamics?
•Cardioversion is the choice
•Safe to the fetus at all trimester
•Transient fetal bradycardia- fetal monitoring
required
•IV heparin- when AF is for more than 48h
SGPGI- PG ARC-

44. Intervention in Pregnancy
• Percutaneous mitral balloon commissurotomy
is reasonable for pregnant patients with severe
MS (mitral valve area ≤1.5 cm2, stage D) with
valve morphology favorable, who remain
symptomatic with NYHA class III to IV HF
symptoms despite medical therapy.
• Preferably be performed after 20 weeks of
gestation
• Presence of LA thrombus is a contraindication
ACC/ AHA 2014
SGPGI- PG ARC-

45. What is favorable valve morphology?
• A mitral valve with a score <8 to 9 with no more than moderate mitral
regurgitation is deemed the best candidate for PBMV.
SGPGI- PG ARC-

46. Does surgery have any role?
• Surgical commissurotomy- Carries high fetal risk (2-
10%)
• MV replacement (CPB)- Risk of fetal loss may be up to
20- 30%
Maternal risk 2-8%
• Patients with severe MS should undergo intervention
before pregnancy
SGPGI- PG ARC-

47. Obstetric Management
SGPGI- PG ARC-

48. Vaginal birth vs LSCS
• “Vaginal delivery, with epidural analgesia, is preferred
for the majority of women. Invasive monitoring
should be used in symptomatic women and those
with severe MS. ”
RCOG 2006
SGPGI- PG ARC-

49. Vaginal birth vs LSCS
• Mild MS, and in patients with moderate or severe MS
in NYHA class I/II without pulmonary hypertension-
Vaginal delivery
• Moderate or severe MS who are in NYHA class III/ IV
or have pulmonary hypertension despite medical
therapy- LSCS can be considered
SGPGI- PG ARC-
ESC 2011

50. Hemodynamics during normal labor
SGPGI- PG ARC-

51. Goals during vaginal delivery
•Second stage of labor to be curtailed
•Avoid pain & sympathetic stimulation
•Epidural analgesia is desirable
•Assisted delivery is the choice
SGPGI- PG ARC-

52. Labor analgesia in mitral stenosis
• Low conc. LA with opioid in epidural
• IT opioid with low conc. LA in epidural (CSE) can be used
• IT opioid (fentanyl 25mcg) can be used as sole agent
• Carefully titrated- avoid sudden vasodilatation
• Epinephrine test dose- Avoid
• FHR monitoring is mandatory
• Goal is to avoid tachycardia & maternal bear down effort
Valsalva maneuver
Increased venous return
Increased CO
Increased MV flow
Increased LA pressure
Increased pulm v. pressure
SGPGI- PG ARC-

53. Anesthetic management
SGPGI- PG ARC-

54. Preoperative investigations
• Hemogram
• Electrolytes (because patients often receive diuretics)
• 12 lead ECG
• 2D Echocardiography with Doppler
• Coagulation profile (Ptime?/ aPTT?)
SGPGI- PG ARC-

55. What monitoring will you use?
• 5-lead ECG
• SpO2
• NIBP
• IBP
• EtCO2
• CVP?
SGPGI- PG ARC-

56. What is the choice of anesthetic technique?
• General anesthesia, spinal anesthesia, epidural
anesthesia & combined spinal epidural anesthesia- all
have been used
• Choice of anesthetic technique depends upon clinical
condition of the patients
SGPGI- PG ARC-

57. Anesthetic Goals
• Heart rate- Avoid tachycardia (60- 70 bpm), maintain sinus
rhythm
• Preload- ‘Optimum’
• Afterload- Not to be reduced (SBP/ MAP to be maintained
within 20% of baseline)
• Contractility- To be maintained
• Decrease PVR
LA pressure
Cardiac output
⬇️ SVR ~ CO ⬇️ DBP ⬇️ CPP
SGPGI- PG ARC-

58. What drug to be used for RV failure?
• Milrinone is the drug of choice
• Typical dose is 50 mcg/kg loading by IV over 10
minutes, then 0.375-0.75 mcg/kg/min IV
• Noradrenaline at low dosage may be needed to
counteract hypotension
SGPGI- PG ARC-

59. Sub- arachnoid block
• Single injection SAB not recommended in severe MS- risk of
sudden fall in SVR
• Low dose SAB (1.2ml- 1.5ml) has been used in mild to
moderate cases.
• Boluses of phenylephrine (40- 100 mcg)- for counteracting
hypotension & fall in SVR
• Continuous spinal catheter- option for titration
SGPGI- PG ARC-

60. Epidural anesthesia
• Can be titrated,
• Slow onset- maternal cardiovascular system may be ‘adapted’
• May be associated with less hemodynamic perturbation
• Larger volume of LA required
• Can’t be used in emergency scenario
SGPGI- PG ARC-

61. Combined spinal- epidural anesthesia
• Faster onset of block
• Quality & duration of block can be increased subsequent epidural LA
injection.
• 5- 6 mg 0.5% heavy bupivacaine can be used
• Epidural supplementation can be provided by 2-3 ml boluses of LA
• Provides excellent postoperative analgesia
• Epidural volume expansion by NS can achieve higher block
SGPGI- PG ARC-

62. General anesthesia: Indications
• Patients with ‘critical MS’
• Patients with pulmonary edema
• Patients on LMWH/ UFH
• Patients who can’t tolerate supine position
SGPGI- PG ARC-

63. How will you provide GA in this patient?
Induction of general anesthesia
Avoid Ketamine- Tachycardia
Propofol- Cause decrease in SVR & hypotension
Thiopentone- Cause myocardial depression
Etomidate- Provides stable maternal hemodynamics
Prevent laryngoscopy & intubation responses
IV lignocaine
IV esmolol
IV short acting opioid: Remifentanil (0.5 mg/kg) is choice, fentanyl (1- 2
mcg/kg) can be considered- Neonatology team must be informed
Avoid tachycardia
Avoid vasodilatation
Avoid hypoxia, hypercarbia
SGPGI- PG ARC-

64. Maintenance of anesthesia
•Nitrous oxide should be avoided if PAH is a concern
•Potent inhalation anesthetics are choice (isoflurane/
sevoflurane)- Risk of uterine atony
•Intermediate acting NM blockers are used
SGPGI- PG ARC-

65. Reversal of GA
• Extubation response must be prevented
• Avoid tachycardia
• Hypoventilation/ hypoxia to be avoided
• Post of pain management is of vital management
(Postop epidural opioid, TAP block)
SGPGI- PG ARC-

66. Fluid & hemodynamics management
• IV fluid to be optimized- prevent pulmonary edema.
• Baby delivery causes auto-transfusion of 500- 700 ml of
blood
• Post spinal hypotension to treated by boluses of
phenylephrine (25– 100 mcg)
• Phenylephrine infusion can also be considered (0.75- 2
mcg/kg/min)
• Avoid beta stimulant drugs (ephedrine/
mephentermine)
SGPGI- PG ARC-

67. How will you guide fluid therapy?
• CVP- Not a predictor of LA pressure
• Acute rise of CVP indicates RV dysfunction
• PCWP is usually overestimates LA pressure
• PA catheter can derive SV, SVR & PVR
SGPGI- PG ARC-

68. Postoperative Hemodynamics
SGPGI- PG ARC-

69. Postoperative pain management
• Postoperative pain management is of paramount
importance- multimodal analgesia
• B/L USG guided TAP block
• Intrathecal morphine (LD:50- 100 mcg/ HD:150- 250 mg)
• Epidural morphine/ oxycodone
• Surgical site LA infiltration
SGPGI- PG ARC-

70. Thank You!