Valvular Heart Disease Mitral Stenosis

1. Valvular Heart Disease Mitral Stenosis Dr. Chitra Rajeswari Dr. Sivakumaran Moderator: Dr. Shende D www.anaesthesia.co.in anaesthesia.co.in@gmail.com

2. Mitral Stenosis • Anatomy • Incidence • Etiology • Symptoms • Physical Exam • Natural history • Complications • Preoperative assessment • Anaesthetic management

3. Two triangular cusps (leaflet) Unequal size Anterior or aortic cusp Placed in front and right of the atrioventricular and aortic orifices Posterior or smaller cusp Behind and to the left of the opening Anatomy

4. Incidence • 10 – 35 % of all cardiac admissions is for ARF & RHD • Pure MS occur in 25% cases of RHD • MS with MR occurs in 40% cases of RHD • Two-thirds of all patients with MS are females (2:1) • Most common lesion associated with RHD

5. Etiology • Primarily a result of rheumatic fever (~ 99% of MV’s @ surgery show rheumatic damage ) • Rarely congenital in infants and children Roberts et al, Ann Intern Med 1972 • Malignant carcinoid • Rheumatoid arthritis • Mucopolysacccharides • Severe annular calcification

6. 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 Rheumatic fever- Jones criteria

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

8. Rheumatic heart disease • Cause pancarditis …long term sequele confined to endocardium • Interval between the RF and the development of MS is 2 years • Asymptomatic for 2 decades • Symptoms develop in 3- 4 decades

9. Pathological process- RF • Leaflet thickening and Calcification (15%) • Commisural fussion (30%) • Chordal fusion (15%) • Combination of these • Results in a funnel shaped mitral apparatus This differential distribution has some functional implications • Chord- regurgitation

10. Pathophysiology

11. Pathophysiology…

12. Pathophysiology… • Increased pulmonary arteriolar resistance • Alveolar basement membrane thickening • Adaptation of neuroreceptors • Increased lymphatic drainage • Increased transpulmonary endothelin spillover rate

13. D PRESSURE C PRESSURE ESV SV EDV B A VOLUME VOLUME Mitral stenosis Normal

14. Transmitral gradient MVA = • Flow K. pressure gradient Cardiac output / diastolic filling time LAP – LVDP If we assume MVA is constant then, • cardiac output 2 Diastolic time • So when cardiac output increases or diastolic time decreases gradient is increased to cause symptoms = LAP- LVDP=

15. Transmitral gradient • Gorlins formula MVA= Flow/ K . pressure gradient Gorlin et al, Am Heart J 1951 • Area > 1.5 cm2 - no symptoms rest • Symptoms occur when •  transmitral flow •  diastolic filling period

16. Effect of tachycardia • Tachycardia shortens diastole proportionately more than systole • Decreases the overall time available for transmitral flow • In order to maintain CO, the flow rate per unit time must increase • Pressure gradient increases by the square of the increase in flow rate

17. Gradient / MVA / Flow

18. 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

19. Dyspnoea PND Orthopnea Palpitations Fatigue Chest pain (25% CAD) Cough Hemoptysis Atrial fibrillation Systemic embolism Pulmonary infection Right sided failure Hepatic Congestion Edema Ortner’s syndrome Symptoms…

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

21. Inspection Engorged vein in neck Palpation: Tapping apex beat Palpable S1 Parasternal haeve 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 Examination

22. Low pitched Mid diastolic Rumbling Presystolic accentuation Mitral area No radiation Best audible Bell of the stethscope Left lateral Height of expiration After mild exercise Murmur in MS

23. Common Murmurs Systolic Murmurs • Aortic stenosis • Mitral insufficiency • Mitral valve prolapse • Tricuspid insufficiency Diastolic Murmurs • Aortic insufficiency • Mitral stenosis S1 S2 S1

24. Differential diagnosis • Carey coombs murmur • Austin flint murmur • Left atrial myxoma • Ball valve thrombus • Tricuspid stenosis • Conducted murmur of AI • Functional

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

26. 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) • Hemoptysis • Massive: 20 to ruptured bronchial veins (pulm HTN) • Streaking/pink froth: pulmonary edema, or infection • Endocarditis • Pulmonary infections

27. Atrial fibrillation • 30- 40% of patients with symptomatic MS develop AF • Structural changes due to pressure and volume over load alter the electrophysiological properties of left atrium • Rheumatic process itself may lead to fibrosis of the internodal and interatrial tracts and damage the nodes

28. Atrial fibrillation • Common in older patients • Poor prognosis • 10 year survival rate of 25% (with AF), 46% (with sinus rhythm) • Risk of arterial embolization (stroke) is significantly increased

29. 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

30. Natural history… • In North America and Europe it has a milder delayed course with the decline in incidence of rheumatic fever • In some other geographic areas it progresses rapidly causing severe symptomatic MS in early 20’s

31. Survival rate • 10 year survival rate • Untreated patients 50- 60% • Minimally symptomatic > 80% • Significant symptoms 0- 15% • With symptomatic MS, 20% patients die within one year & 50% die within 10 years • Once severe pulmonary hypertension develops mean survival drops to less than 3 years

32. Causes of mortality • Untreated MS

33. ECG

34. Chest x-ray

35. Chest x-ray…

36. Chest x-ray…

37. Chest x-ray…

38. ECHO • 2D and Doppler ECHO is the diagnostic tool of choice • Dilated left atrium • Restricted diastolic opening of the MV leaflets • Doming of the anterior leaflet • Immobility of the posterior leaflet • Planimetry of the orifice in short- axis view

39. ECHO • Morphology of MV • Leaflet mobility and flexibility • Leaflet thickness • Calcification • Subvalvular fusion • Appearance of commissures • Doppler • Mean transmitral gradient • MV area by Half time method • Pulmonary artery systolic pressure

40. Echocardiography- class I • Diagnosis of Mitral Stenosis, Mean gradient, mitral valve area, pulmonary artery pressure • Concomitant valve lesion • Valve morphology • Left atrial thrombus • TEE when trans thoracic ECHO provides suboptimal data

41. Echocardiography- class IIa • ECHO is reasonable in the re-evaluation of asymptomatic patients with MS and stable clinical findings to assess pulmonary pressure

42. Cardiac catheterisation Indications - Class I • Assessment of severity • When noninvasive tests are inconclusive • Discrepancy between the non invasive and clinical symptoms • To evaluate the severity of MR when there is discrepancy between Doppler derived mean gradient and valve area

43. Cardiac catheterisation • Uses • Trans mitral pressure gradient • Mitral valve area • Left ventricular function • Right sided pressures

44. 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

45. Classification ACC AHA Guidelines 2006

46. Classification… • A2- OS interval • Longer duration of diastolic rumble • Loud P2 • Right ventricular heave

47. Classification… • Pressure half time

48. Initial evaluation • History • Physical examination • CXR • ECG • 2D ECHO/ Doppler

49. Asymptomatic Mild MS Valve area > 1.5 cm2 Moderate to severe MS MVA < 1.5 cm2 Valve morphology Favorable for PMBV? Yearly follow up With history, exam CXR, ECG No Yes PASP > 50 mm Hg? No Yes Class I Exercise Poor exercise tolerance, PASP >60 mmHg, PAWP > 25 mmHg Consider PMBV Class I No Yes Exclude LA clot 3+ to 4+ MR No Yes New onset AF Class IIb

50. NYHA Class II Moderate or Severe stenosis MVA < 1.5 cm2 Mild stenosis MVA > 1.5 cm2 Exercise Valve morphology Favorable for PMBV PASP > 60 mmHg PAWP > 25 mmHg MVG > 15 mmHg No Yes Yes No Valve morphology Favorable for PMBV Severe PH PAP > 60 mmHg Yes No Yes No Consider Commisurotomy Or MVR 6- month Follow up Yearly Follow up 6- month Follow up Consider PMBV