1. Anesthesia for Valvular Heart Surgery*
07/16/96
Anesthesia for Valvular Heart Surgery
Charles E. Smith, MD
Professor of Anesthesia
Director, Cardiothoracic Anesthesia
MetroHealth Medical Center
Case Western Reserve University *

2. Objectives Pathophysiology Hemodynamic Goals Anesthetic management*
07/16/96
Objectives
Pathophysiology
Aortic valve: AS, AI
Mitral valve: MS, MR
Tricuspid valve: TR
Hemodynamic Goals
Anesthetic management *

3. Aortic Stenosis May occur at 3 levels: Valvular Subvalvular*
07/16/96
Aortic Stenosis
May occur at 3 levels:
Valvular
Subvalvular
Supravalvular *

4. Valvular Aortic Stenosis*
07/16/96
Valvular Aortic Stenosis
Calcification + fibrosis of normal tricuspid valve- very common
Calcification + fibrosis of congenital bicuspid AV
Rheumatic- uncommon since antibiotics *

6. Aortic Stenosis Normal AVA: 2-4 cm2 Severe AS: AVA < 1cm2*
07/16/96
Aortic Stenosis
Normal AVA: 2-4 cm2
Severe AS: AVA < 1cm2
If normal LV- mean PG > 50 mmHg
If poor LV function- mean PG may be low! *

7. *
07/16/96 *

8. Pathophysiology of Aortic Stenosis*
07/16/96
Pathophysiology of Aortic Stenosis
Chronic LV pressure overload
Concentric LVH to ↓ wall stress
LVH → ↓ diastolic compliance, ↓ coronary blood flow + imbalance of MVO2 supply-demand
↓ diastolic compliance → ↑LVEDP + LVEDV
Myocardial ischemia bc LVH, ↑ wall stress, ↓ diastolic coronary perfusion + ↓ coronary flow reserve *

9. *
07/16/96 *

10. Hemodynamic Goals: AS SR is crucial. Cardiovert SVTs promptly*
07/16/96
Hemodynamic Goals: AS
SR is crucial. Cardiovert SVTs promptly
Optimal HR Tachycardia → ischemia + ectopy. Bradycardia → low CO due to fixed SV
Adequate preload essential but difficult to predict bc diastolic dysfunction [TEE useful]
Maintain contractility. Avoid myocardial depressants
Treat hypotension promptly- phenylephrine, volume, Trendelenburg *

11. AS: Considerations Drugs to maintain CPP: Phenylephrine Norepinephrine*
07/16/96
AS: Considerations
Drugs to maintain CPP:
Phenylephrine
Norepinephrine
Atrial kick – crucial. HR preferred
Spinal + epidural anesthesia poorly tolerated if  preload or  HR *

12. *
07/16/96
AS: Management
Premed: young+ anxious get benzos. Frail + elderly  dose (or avoid)
Intraop: std monitoring + preinduction art line.
Resting HR Avoid myocardial depressants
CVP, PAC, TEE- routine for optimal management *

13. AS: Weaning from Bypass*
07/16/96
AS: Weaning from Bypass
Thick, hypertrophied heart may be difficult to protect- stone heart still occurs (rare)
Noncompliant LV dependent on stable rhythm
Inotropes if preop LV dysfunction
Dynamic subaortic or cavitary obstruction after AVR if septal LVH
Tx w volume, β-blockers. Rarely need myomectomy [inotropes worsen obstruction] *

14. Septal LVH with SAM. Tx= volume + beta-blockers*
07/16/96
Septal LVH with SAM. Tx= volume + beta-blockers *

15. Aortic Regurgitation: Etiology
Aortic root dilatation- HTN, ascending aorta dissection, cystic medial necrosis, Marfans, syphilitic aortitis, ankylosing spondylitis, osteogenesis imperfecta
Deformed + thickened cusps- rheumatic, IE, bicuspid valve
Cusp prolapse- dissection

17. Horse kick to upper chest with severe AI. *
07/16/96
From horse kick to lt upper chest. Tee showed thickening+ prolapse of av leaflets. There was a disruption of the attachment of the RCC to the STJ
Horse kick to upper chest with severe AI.
The RCC was torn from the STJ *

18. Pathophysiology: Chronic AR
Asymptomatic for many years
LV volume + pressure overload occurs
LV maintains systolic fct by dilation ↑ compliance
LV decompensates at later stages w ↑ LVEDP + LVEDV→ CHF, arrhythmias, sudden death

19. Pathophysiology: Acute AR
LV unable to dilate acutely
LV volume overload occurs
↑ LVEDP + LVEDV→ acute pulmonary edema
Emergency surgery often needed

20. Hemodynamic Goals: AR Optimal HR= 90. Avoid bradycardia- ↑ regurg
Avoid high afterload
SNP preferred
Acute AR- often need inotropes + vasodilator [epi+ SNP/milrinone]
IABP- contraindicated

21. Anesthetic Management: AR
Premed w benzos
Routine monitoring: art line, CVP, PAC
TEE beneficial
Narcotic based technique if impaired LV
If acute AR: RSI w ketamine-succinylcholine
Inotropes if acute AR or preop LV dysfunction

22. Mitral Stenosis
Usually rheumatic- thickening, calcification + fusion of MV leaflets + commissures
May be combined w MR + AR
Surgery if MVA < 1 cm2 w NYHA class III or IV dyspnea [or embolus- LAA clot]

24. MS- Pathophysiology
Pressure gradient between LA + LV- prevents LV filling
Pulmonary HTN w ↑ LAP
↑ LAP → LAE, atrial arrhythmias (Afib)
Pulm HTN → RV dysfct, RVE, TR [may need TV repair]
LV dysfct uncommon unless CAD

25. *
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26. *
07/16/96 *

27. MS: Hemodynamic Goals Preserve SR, if present*
07/16/96
MS: Hemodynamic Goals
Preserve SR, if present
Avoid tachycardia which ↓ diastolic filling of LV + worsens MS
Avoid factors which worsen pulmonary HTN- hypercarbia, acidosis, hypothermia, sympathetic nervous system activation, hypoxia *

28. Anesthetic Management: MS*
07/16/96
Anesthetic Management: MS
Premed: benzos to avoid tachycardia
If pulm HTN- supplemental O2
Control of HR- β blockers, digoxin, CEB, amiodarone *

29. Intraop Management: MS*
07/16/96
Intraop Management: MS
Std monitors + CVP, PAC, TEE
PAP underestimates LVEDP + LVEDV
Esmolol:
single most useful drug with severe MS, even if CHF + pulmonary edema
10-20 mg bolus; mcg/kg/min
N2O avoided bc effects on pulm HTN
Panc avoided bc tachycardia *

30. Weaning from Bypass: MS*
07/16/96
Weaning from Bypass: MS
MV replacement- hemodynamics usually improved bc obstruction to LV filling resolved
If preop pulm HTN + RV dysfct may need milrinone or nitric oxide *

31. Mitral Regurgitation: Etiology*
07/16/96
Mitral Regurgitation: Etiology
Myxomatous degeneration (most common)
Ischemic (functional)- papillary muscle dysfunction, annular dilatation, LV dysfct + tethering
Infective endocarditis
Trauma *

32. Papillary muscle rupture after blunt trauma*
07/16/96
Papillary muscle rupture after blunt trauma
Papillary muscle rupture after blunt trauma *

33. MR- Pathophysiology Volume overload of LV→ LVE, LAE*
07/16/96
MR- Pathophysiology
Volume overload of LV→ LVE, LAE
LA can massively dilate
Atrial arrhythmias with LAE
Dilated LV decompensates at later stages w  LVEDV *

34. Chronic MR. Dilated LA w normal LAP*
07/16/96
Chronic MR. Dilated LA w normal LAP *

35. Chronic MR. Dilated LA w normal LAP*
07/16/96
Chronic MR. Dilated LA w normal LAP
Acute MR. Small LA with ↑ ↑ LAP+ pulmonary edema *

36. Severity of MR Pressure gradient between LA + LV
Size of regurgitant orifice (ERO)
Duration of ventricular systole

37. Hemodynamic Goals- MR:*
07/16/96
Hemodynamic Goals- MR:
Vasodilators: NTG, SNP - ↓ afterload + regurgitant fraction + ↑ forward flow
High normal HR to ↑ time of ventricular systole
Maintain contractility *

38. Anesthetic Management MR:*
07/16/96
Anesthetic Management MR:
MV repair (v. replacement)
preserved papillary muscle + chordae
enhanced LV function
requires TEE to assess repair
LV dysfct unmasked after MV surgery bc LV cannot offload into LA
May need inotropes + vasodilators *

39. Tricuspid Regurgitation
Primary: rheumatic, IE, carcinoid, Ebstein’s, trauma
Secondary: chronic RV dilatation, often w MV disease

40. Flail TV after blunt trauma

41. TR- Pathophysiology RV + RA overloaded + dilated
RA v compliant so RAP rises only w end stage disease
Pulm HTN due to MV disease ↑ RV afterload + worsens TR
RVE → paradoxical motion LV septum w imapired LV filling + compliance
Right heart failure: hepatomegaly, ascites

42. TR- Hemodynamic Goals If secondary to MV- treat left heart lesion
Avoid pulm HTN + high PVR
Normal to high preload for RV stroke volume
Hypotension treated w inotropes + volume bc vasoconstrictors may worsen pulm HTN

43. TR- Anesthetic Management
Premed- benzos
Std monitors + art line, CVP, TEE
PAC if pulm HTN + MV pathology; but CO overestimated w severe TR. May be impossible to float Swan
Weaning from CPB: if preop RV dysfunction/ dilation- inotropes, inodilators, vasodilators, nitric oxide

44. Summary- I Knowledge of patient + extent of valvular heart disease*
07/16/96
Summary- I
Knowledge of patient + extent of valvular heart disease
Functional + hemodynamic status
Co-morbidities
Planned surgery: cannulation sites, repair vs replacement, minimally invasive vs full bypass.
Inotropes, vasodilators, vasopressors, infusion pumps *

45. *
07/16/96
Summary- II
Understand pathophysiology of lesions + hemodynamic goals: AS, AR, MS, MR, TR
Monitoring: standard + invasive +TEE
Anesthetic technique: most can be used safely.
Adjustment of dosages more important than adhering to a rigid anesthetic technique. *