1. Aortic Stenosis Dr Amarja www.cardiacanaesthesia.in| Dr Amarja

2. Aortic Stenosis www.cardiacanaesthesia.in| Dr Amarja

3. Signs & Symptoms 1. DOE 2° to CHF (50%) 1-2 yrs 2. Angina (35%) 5 yrs 3. Effort Syncope (15%) 3-4 yrs www.cardiacanaesthesia.in| Dr Amarja

4. Source: Am J Geriatr Cardiol 12(3):178-182, 2003 www.cardiacanaesthesia.in| Dr Amarja

5. Signs & Symptoms (cont.)  Other rare initial findings include  Embolization from a calcified aortic valve resulting in unilateral vision loss, focal neurologic deficit & MI  Heyde’s Syndrome- Angiodysplasia due to Von Willebrand factor deficiency leading to GI bleeding. www.cardiacanaesthesia.in| Dr Amarja

6. DOE - CHF (50%)  CHF can cause  Dyspnea on Exertion  Orthopnea  Paroxysmal Nocturnal Dyspnea  Diastolic CHF (early)  Secondary to  wall thickness & collagen deposition in walls which leads to ventricular wall stiffness  Systolic CHF (late)  Due to LV dilation www.cardiacanaesthesia.in| Dr Amarja

7. Contd...  Mechanism - Pulm congestion due to raised LVEDP - Exertional symtoms due to limited increase in CO during exercise www.cardiacanaesthesia.in| Dr Amarja

8. Heart Failure  Right Heart Failure  Edema  Congestive hepatomegaly  JVD  Left Heart Failure  Rales in lungs www.cardiacanaesthesia.in| Dr Amarja

9. Angina (35%)  AS without CAD – secondary to myocardial ischemia (O 2 demand exceeds supply)  Hypertrophied myocardium & compressed coronaries  AS with CAD – Combination of both  Concentric LVH develops secondary to pressure overload of AS… …The Law of Laplace www.cardiacanaesthesia.in| Dr Amarja

10. Law of Laplace LV Wall Stress = Pressure x Radius 2 x Thickness Wall Stress = O 2 Demand X HR Hence, Wall Stress  O 2 Demand www.cardiacanaesthesia.in| Dr Amarja

11. Effort Syncope (15%)  Secondary to inadequate cerebral perfusion  During exercise TVR (total vascular resistance)  so that more blood can get to muscles, but CO cannot  in AS as it is a fixed low cardiac output state MAP(or BP) = CO x TVR  Exercise - ventricular & supravent arrthy  Secondary AF- loss of atrial kick : 40 % www.cardiacanaesthesia.in| Dr Amarja

12. Effort Syncope (contd)...  Malfunction of baroreceptor  Vasodepressor response  Hampered myocardial blood supply – arrythmias  Calcification – conduction system – heart blocks Syncope at rest – transient VF / AF www.cardiacanaesthesia.in| Dr Amarja

13. Other symptoms  GI bleed  Infective endocarditis  Cerebral emboli  Calcification - Ca ++ - Central retinal artery www.cardiacanaesthesia.in| Dr Amarja

14. Coagulation Abnormalities  In most pts with severe AS, impaired platelet function and decreased levels of Von Willebrand factor are noted  Severity of coagulation problem correlates with degree of AS  Associated with clinical bleeding in 20% of patients  Resolves after valve replacement www.cardiacanaesthesia.in| Dr Amarja

15. AS  Normal AVA – 2.5 – 3.5 cm2  Mild : > 1 cm2 and PG < 25 mmHg  Mod : 0.7 – 1 cm2 / PG : 25-50 mmHg  Sev : 50 mmHg www.cardiacanaesthesia.in| Dr Amarja

16. LVOTO - AV  Valvular  Supravalvular  Subvalvular  HOCM www.cardiacanaesthesia.in| Dr Amarja

17.  Supravalvular  Subvalvular  discrete  tunnel  Valvular  congenital (1-30yrs old)  bicuspid (40-60yrs old)  rheumatic (40-60yrs old)  senile degenerative (>70yrs old) www.cardiacanaesthesia.in| Dr Amarja

18. Supravalvular AS  Congenital abnormality in which ascending aorta superior to the aortic valve is narrowed  Rarest site of AS  Either a single discrete constriction or a long tubular narrowing www.cardiacanaesthesia.in| Dr Amarja

19. Supravalvular AS contd…..  Should be suspected in young pt with LVOT murmur  On physical exam - thrill felt on palpation of right carotid but not left  On 2D echo - visualization of narrowed ascending aorta  Doppler – for magnitude of obstruction www.cardiacanaesthesia.in| Dr Amarja

20. Supravalvular AS (contd)…..  Associations:  Elfin facies  Hypercalcemia  Peripheral Pulmonic stenosis www.cardiacanaesthesia.in| Dr Amarja

21. Subvalvular AS  Discrete seen in 10% of all pts with AS  Can be secondary to a subvalvular ridge that extends into LVOT or to a tunnel-like narrowing of the outflow tract  Aortic regurgitation frequently accompanies www.cardiacanaesthesia.in| Dr Amarja

22. Subvalvular AS contd…..  Echo - visualization of a narrowing or discrete subvalvular ridge extending into the LVOT and a high-velocity turbulence on continuous wave doppler  If site of obstruction is not visualized on transthoracic echo, TEE is indicated www.cardiacanaesthesia.in| Dr Amarja

23. Subvalvular vs HCM  Diagnosis of subvalvular AS needs to be differentiated from dynamic outflow obstruction of HCM as management differs  Discrete subvalvular - some recommend resection in all pts with moderate or higher to relieve degree of LVOT obstruction and prevent progressive AR www.cardiacanaesthesia.in| Dr Amarja

24. Valvular AS  Accounts for most cases  Cause of valve abnormality depends on age at presentation  Teens to early 20’s - congenitally unicuspid or fused bicuspid valve  40’s to 60’s - calcified bicuspid or rheumatic disease  70’s and beyond - senile degeneration of valve with calcific deposits www.cardiacanaesthesia.in| Dr Amarja

25. Etiology 1. Tricuspid Aortic Valve Degeneration 2. Bicuspid Aortic Valve 3. Congenital Aortic Stenosis 4. Rheumatic Fever 5. Other Causes www.cardiacanaesthesia.in| Dr Amarja

26. Aortic Valve Variations  A – Normal Valve  B – Congenital AS  C – Rheumatic AS  D – Bicuspid AS  E – Senile AS From Brandenburg RO, et al: Valvular heart disease—When should the patient be referred? Pract Cardiol 5:50, 1979 www.cardiacanaesthesia.in| Dr Amarja

27. Calcific AS  Senile Degeneration secondary to calcifications  Most common cause of AS age > 70 yrs  Risk factors –DM, HTN, smoking &  Cholesterol Concept –  1) Proliferative & inflammatary changes www.cardiacanaesthesia.in| Dr Amarja

28. Contd...  2) Lipid changes  3) Upregulation of ACE activity  4) Infiltration - macrophages T lymphocytes Genetic polymorphism Linked – inflam markers, metabolic syn. HMG-coA reductase (statins) www.cardiacanaesthesia.in| Dr Amarja

29. Bicuspid Aortic Valve  Most common congenital heart anomaly  Most common cause of AS age < 70 yrs  50% develop mild AS by age 50  Increased incidence in Turners Syndrome www.cardiacanaesthesia.in| Dr Amarja

30. Congenital AS  Fusion of valve leaflets before birth  70-80 %  M > F  Familial – autosomal dominant, NOTCH 1  More hypertrophy yet patients almost never develop heart failure symptoms  15% encounter sudden death www.cardiacanaesthesia.in| Dr Amarja

31. Congenital AS (contd)….  AR – 20 %  Endocarditis risk  Asc aorta dilatation, degeneration  Aortic dissection : 5-9 times  Pts present early www.cardiacanaesthesia.in| Dr Amarja

32. Rheumatic Fever  Fusion – cusps, commissures  Calcific nodules  Valve - stenotic & regurgitant  With mitral valve abnormality www.cardiacanaesthesia.in| Dr Amarja

33. Other Causes  SLE  Severe Familial Hypercholesterolemia  Fabry’s Disease  Ochronosis  Paget’s Disease of the Bone www.cardiacanaesthesia.in| Dr Amarja

34. Pathophysiology  In AS - LVOTO develops  LV output - LVH – sustains large PG without :lowering CO : LV dilatation : dev symptoms Ch pressure overload - // sarcomere replication = concentric LVH www.cardiacanaesthesia.in| Dr Amarja

35. Contd...  Increased wall thickness - normalizes wall stress - contractility maintained  But, increased myocardial cell mass & interstitial fibrosis – diastolic dysfunction www.cardiacanaesthesia.in| Dr Amarja

36. LVH causes what ?  Altered diastolic compliance  Myoc O2 supply / demand imbalance  Myoc contractility decreased  Increases basal MVO2 www.cardiacanaesthesia.in| Dr Amarja

37. Contd...  Reduced LV compliance – increases LVEDP - decreases diastolic CPP gradient  Also, decrease in SV - systemic hypotension – decrease in CP www.cardiacanaesthesia.in| Dr Amarja

38. Pressure overload hypertrophy  Benefits – increases vent work normalizes wall stress & systolic shortening  Detrimental - decreases vent diastolic distensibility - impairs vent relaxation - impairs coronary vasodilator reserve - subendocardial ischaemia www.cardiacanaesthesia.in| Dr Amarja

39. Pressure – Volume Loop www.cardiacanaesthesia.in| Dr Amarja

40. PV loop (contd…)  Peak pressure during systole – high due to high PG  Slope of diastolic limb is steep – due to low LV compliance  Clinically, small changes in diastolic volume = large increase in ventricular filing pressure www.cardiacanaesthesia.in| Dr Amarja

41. AS associated pathology...  LVH  Diastolic dysfunction  MR  Aortic root / asc aorta dilatation  Aortic atherosclerosis  Other valves calcifications  CAD www.cardiacanaesthesia.in| Dr Amarja

42. Low gradient low flow AS  Mean PG < 30 mmHg & AVA < 1 cm 2  Dobutamine stress test is done to differentiate between this type of AS and LV dysfunction. www.cardiacanaesthesia.in| Dr Amarja

43. Auscultation: Heart Sounds  Paradoxic Splitting of S 2  Absent/Soft A 2 which leads to a soft S 2  S 4 in early AS due to LVH/diastolic CHF  S 3 in late AS due to systolic CHF  Ejection click with bicuspid valve www.cardiacanaesthesia.in| Dr Amarja

44. Auscultation: Murmurs  Systolic Ejection Murmur  Located at the RUSB radiating to carotids  As AS worsens, murmur peaks progressively later (  intensity, possible thrill)  Severe AS, murmur may  as CO falls hence intensity is not a predictor of severity  Gallivardin’s Phenomenon when AS is heard at the apex and may even sound holosystolic www.cardiacanaesthesia.in| Dr Amarja

45. Apical Impulses  usually not displaced due to concentric LVH  abnormally forceful & sustained in nature – heaving type  laterally displaced with severe CCF www.cardiacanaesthesia.in| Dr Amarja

46. Carotid Upstroke  Low blood volume & delay in reaching its peak  “Pulsus parvus et tardus” probably the single best way to estimate the severity of AS at the bedside  In elderly patients, stiff carotids may falsely normalize the upstroke www.cardiacanaesthesia.in| Dr Amarja

47. Diagnostics  EKG  CXR  ECHO  Cardiac Catheterization www.cardiacanaesthesia.in| Dr Amarja

48. EKG  Nonspecific for AS  LVH  LAE  LBBB  ST/T wave changes www.cardiacanaesthesia.in| Dr Amarja

49. CXR  May have normal sized heart  Calcification of aortic valve  Pulmonary congestion  Post-stenotic dilatation of the aorta www.cardiacanaesthesia.in| Dr Amarja

50. Post Stenotic Dilatation www.cardiacanaesthesia.in| Dr Amarja

51. ECHO  Can confirm diagnosis  Aortic valve thickness  Reduced leaflet mobility  Concentric LVH  Quantify severity of AS with Doppler www.cardiacanaesthesia.in| Dr Amarja

52. Class 1 Echo Recommendations  Echocardiography is recommended for diagnosis and severity of AS  Recommended in patients with AS for assessment of LV wall thickness, size, and function  Recommended in patients with known AS and changing symptoms  Recommended for assessment of changes in hemodynamic severity and LV function in pts with known AS during pregnancy  Recommended for re-evaluation of asymptomatic patients: severe AS - yearly; moderate AS - every 1-2 years; mild AS - every 3-5 years www.cardiacanaesthesia.in| Dr Amarja

53. ECHO (cont.)  Quantifying severity of AS with Doppler  Aortic valve area  Bernoulli’s Equation A 2 = (A 1 V 1 ) / V 2  Pressure gradient across valve  Modified Bernoulli’s Equation Gradient = 4V 2  In general a mean gradient of > 50mmHg or an aortic valve area < 0.8cm 2 usually manifests with symptoms for AS www.cardiacanaesthesia.in| Dr Amarja

54. ECHO (cont.)  Criteria for determining severity of AS G (mmHg)AVA (cm 2 ) Mild< 25> 1.5 Moderate25-501-1.5 Severe50-800.7-1 Critical>80<0.7 www.cardiacanaesthesia.in| Dr Amarja

55. Cardiac Catheterization  Measures Peak to peak pressures  Indicated when angina may be secondary to CAD or when AVR is planned  CO & gradient are measured and used to calculate the AVA  CO is determined by the Fick principle or the indicator-dilution principle (usually thermodilution)  The gradient is achieved by comparing pressures in the LV and aorta with catheters www.cardiacanaesthesia.in| Dr Amarja

56. Class 1 Indications for Cardiac Catheterization Coronary angiography is recommended before AVR in pts with AS at risk for CAD Cardiac cath for hemodynamic measurements is recommended for assessment of severity of AS in symptomatic pts when noninvasive tests are inconclusive or there is a discrepancy between non- invasive tests and clinical findings Coronary angiography is recommended before AVR in pts with AS for whom a pulmonary autograft (Ross procedure) is contemplated and if the origin of the coronary arteries is not identified by noninvasive techniques www.cardiacanaesthesia.in| Dr Amarja

57. AVA  In cardiac cath lab, AVA is calcuated from pressure gradient and an independent measure of cardiac output  AVA = 1000 X CO 44 X SEP X HR X s.r of delta P SEP is systolic ejection period P is pressure difference across valve www.cardiacanaesthesia.in| Dr Amarja

58. AVA contd…  Echo and doppler estimate aortic valve area by the continuity equation AVA = LVOTarea X LVOTvti AVvti AV = aortic valve flow velocity VTI = velocity-time integral  Doppler echo may underestimate AV gradient www.cardiacanaesthesia.in| Dr Amarja

59. Cardiac Catheterization (cont.)  The Gorlin formula is used to calculate the aortic valve area  AVA = CO/SEP x HR or simply… 44.3  G  AVA = CO /  G www.cardiacanaesthesia.in| Dr Amarja

60. Treatment  The only effective treatment is relief of the mechanical obstruction via…  Surgical AVR  Aortic Valve Debridement ( AI )  Aortic Balloon Valvuloplasty www.cardiacanaesthesia.in| Dr Amarja

61. AVR Surgery  Mortality rate is 2-3%  Indicated for ALL symptomatic patients & when AS is rapidly progressing or if severe valve calcifications are present  When AVA 4 m/s  Usually not indicated for asymptomatic patients  In Congenital AS surgery is recommended when gradient reaches 75mmHg www.cardiacanaesthesia.in| Dr Amarja

62. Recommendations for AVR AVR is indicated for  symptomatic pts with severe AS  pts with severe AS undergoing CABG  pts with severe AS undergoing surgery on aorta or other heart valves  pts with severe AS and LV systolic dysfunction (EF<50%) www.cardiacanaesthesia.in| Dr Amarja

63. AVR in Advanced Disease  Still beneficial  No  in mortality  EF may immediately double & eventually normalize  LVH may regress www.cardiacanaesthesia.in| Dr Amarja

64. AVR Contraindications  Most patients with a low transvalvular gradient (<30mmHg) & far advanced heart failure do not improve post AVR www.cardiacanaesthesia.in| Dr Amarja

65. Aortic Balloon Valvuloplasty  Beneficial in congenital AS  No regression of LVH in adults  Gradient reduced by only 50%  50% AS recurrence after 6months  Same mortality rate as AVR  Palliative measure for those who cannot undergo AVR or are awaiting AVR www.cardiacanaesthesia.in| Dr Amarja

66. AV Repairs  Bicuspid stenotic valves  David’s procedure – enlarged root ; repair of AV & replacement of ascending aorta www.cardiacanaesthesia.in| Dr Amarja

67. Anaesthesia... Goals According to Cardiac Grid –  Sinus rhythm  Heart rate – no extremes  Preload - increased  Afterload – increased  Hypotension – No  Intravascular volume – adequate  Myocardial ischaemia - avoid www.cardiacanaesthesia.in| Dr Amarja

68. Anaesthesia …Monitors  All cardiac monitors, TEE  CVP – less useful  PA catheter – arrythmias can occur but fluid management CO, SvO2 measurement pacing can be done  Temperature Monitoring www.cardiacanaesthesia.in| Dr Amarja

69. Induction  Narcotic – blunts sympathetic response  Inhalational – negative inotropic effect arrythmias – atrial kick lost Relaxants – Pancuronium / others NTG, Phenylephrine - used www.cardiacanaesthesia.in| Dr Amarja

70. AS – Non-cardiac surgery  Risk of – MI, CCF, SVT  Morbidity raised  AV should be treated first www.cardiacanaesthesia.in| Dr Amarja

71. LV remodelling  Influenced by-severity of insult ishaemia neurohormonal activation genetic factors  Benefitted by – ACEI,cardivolol,correction of cause, Dor procedure www.cardiacanaesthesia.in| Dr Amarja

72. TEE  Peak AS jet velocity  Transaortic PG  Aortic valve area- Planimetry  LVOT diameter  AVA – continuity equation : 2 velocities proximal & distal to AV – Vmax. AVA = Area (LVOT). V(LVOT)  TG – Bernoulli equation PG= 4 v2, V is maximal transvalvular velocity of blood flow www.cardiacanaesthesia.in| Dr Amarja

73. PPM  Prosthesis with EOA smaller for patient’s BSA  So, high TG occurs  Moderate PPM – iEOA=0.65 – 0.85 cm 2 /m 2  Severe PPM - < 0.65 cm 2 /m 2  Interferes with afterload, LV remodelling www.cardiacanaesthesia.in| Dr Amarja

74. Valve in valve replacement  Percutaneous valve replacement  Through – FA, Apex, Asc aorta  Minithoracotomy  Echo guided  Stroke – 30 % - Calcium shower  Highly morbid patients www.cardiacanaesthesia.in| Dr Amarja

75. Thank You www.cardiacanaesthesia.in| Dr Amarja