Valvular Heart Disease II The Aortic Valve - Download as PowerPoint

							Valvular Heart Disease II:
    The Aortic Valve

     Laura Wexler, M.D.
           475-6383
    wexlerl@ucmail.uc.edu
        Reference Sources for
        Valvular Heart Disease
Reading: Harrison, 14th Edition p 1311-1323
Computer:
Umedic: Aortic stenosis, aortic
 regurgitation, mitral stenosis, mitral
 regurgitation
Instructional Programs:
    Heart Sounds and Murmurs
Case:
 An active 75 yo farmer comes to your office after
 experiencing a fainting spell while baling hay. The
 episode occurred without warning and he had no
 symptoms following the episode. However, on
 close questioning he admits to some breathlessness
 and vague chest heaviness with his usual heavy
 exertion over the past few months. He has been
 healthy all his life, doesn‟t smoke and has not seen
 a doctor in 30 years. He served in the army in
 1942; no abnormalities were reported during his
 induction physical.
                   Physical Exam
Robust looking older man.

BP 135/90        P 68 bpm, regular       RR-12       T-98.6 F

JVP 6 cm with normal “a” and “v” waves

Carotids: Difficult to palpate, delayed upstroke

Lungs: Clear

Heart: Palpation: Palpable “thrill” over the mid LSB. PMI 5 ICS, 2 cm lateral
to the MCL. Palpable presystolic impulse followed by a sustained ventricular
lift.
        Auscultation: Loud S4. S1 is normal. A single S2 (P2) is heard at the
upper left sternal border but no A2 is heard at the lower left sternal border.
There is a 4/6 systolic ejection murmur (crescendo-decrescendo) heard best at
the R 2nd interspace that radiates widely to the LSB, and to the neck. No
diastolic murmurs.

Abdomen and extremities are unremarkable.
Aortic Stenosis
Norma Burns:




               Aortic Stenosis: Etiology

          Congenital bicuspid aortic valve

          Rheumatic aortic valve disease

          Calcific (senile) aortic stenosis
Pathophysiology of Aortic Stenosis
 Left ventricular outflow obstruction
      LV systolic pressure > aortic pressure
 Concentric left ventricular hypertrophy
     Sustains high LV pressures
     Normalizes wall stress (radius x pressure/wall
     thickness)
     Eventually results in impaired LV diastolic
     compliance
 LA hypertrophy and enlargement
 Severe stenosis: Limits ability to increase stroke
  volume on demand
      Critical aortic stenosis = fixed cardiac output
Key Physical Findings in Severe
       Aortic Stenosis
 Carotid impulse: “parvus et tardus”
 JVP: Prominent “a” wave
 Heart:    Systolic thrill
            Palpable presystolic impulse (S4)
            Sustained apical systolic impulse
            S4
            Coarse late peaking systolic ejection murmur
                   (may radiate to neck and/or LSB)
            Attenuated/absent aortic component of S2
Natural History of Aortic Stenosis
 Long asymptomatic “latent” period
 “Cardinal” symptoms of severe aortic stenosis
            Dyspnea
            Angina
            Syncope
 Sudden death
 Left ventricular dilatation and contractile failure
 Endocarditis
 Arrhythmias
     Ventricular tachycardia
     Conduction system disease
     Atrial fibrillation
Natural History of AS
Mechanisms of Dyspnea in
    Aortic Stenosis

 LVH  diastolic dysfunction

 Progressive LV dilation and
  contractile failure  systolic
  dysfunction
Mechanisms of Anginal Chest Pain in
         Aortic Stenosis
    Increased wall stress  increased
     myocardial O2 demand, exceeds
     ability to coronary flow to meet
     demand

    Associated coronary artery disease
    Mechanisms of Syncope in
        Aortic Stenosis
Fixed cardiac output: Vasodilation
 (exercise, vagal stimulation, drug induced),
 inability to augment CO, drop in cerebral
 perfusion pressure.

Heart block: Ca++ deposits in aortic ring
 encroach upon conduction tissue

Ventricular arrhythmias (LVH, ischemia)
Diagnostic Studies in Aortic Stenosis
  ECG: LVH with repolarization changes “strain
   pattern”
  Chest X-Ray: Aortic root dilation
                    (aortic valve Ca++)
  Echo: Aortic valve thickening and restricted
       motion
  Doppler: Gradient across aortic valve and aortic
   valve area can be estimated from increased flow
   velocity across aortic valve
  Cath: Measure gradient across aortic valve and
   calculate valve area
Aortic Stenosis
      Treatment of Aortic Stenosis
 Mild to moderate asymptomatic aortic stenosis:
      Close follow up: History and physical exam, serial
                    echocardiograms
      Endocarditis prophylaxis
 Severe, symptomatic aortic stenosis (1 year survival 57%)
     Aortic valve replacement with either mechanical or
     bioprosthetic valve
      - Ten year survival ~75%
      - Complications of prosthetic heart valves:
             infection, thromboembolism, mechanical
             failure
 Severe, symptomatic aortic stenosis NOT surgically treatable:
      Palliative option: aortic balloon valvuloplasty
CASE:
 A 52 yo salesman is referred to you for
 evaluation of a heart murmur. He had applied
 for a pilot‟s license and was denied because of
 the murmur. He is asymptomatic and
 physically active. He denies chest pain,
 dyspnea or dizzy spells and gives no history of
 a murmur being mentioned during his last
 physical exam five years ago. He has no family
 history of heart disease. He has never had high
 blood pressure or diabetes, doesn‟t smoke, and
 takes no medications. A lipid profile done five
 years ago was reported to be “OK”.
                  Physical Exam
BP - 145/45        P - 78 reg       RR - 12      Temp:98.6F
Carotids:     Very brisk with sharp collapse
JVP:          5 with normal „a‟ and „v‟ waves
Lungs:        Clear
Heart: Palpation:    PMI is enlarged (4fb), in the anterior
               axillary line
       Auscultation: S1 normal, S2 soft. A 2/6 early peaking
       systolic ejection murmur at the upper RSB and a 3/6
       holodiastolic blowing murmur, heard best at the lower
       LSB when you ask the patient to hold his breath in
       expiration and lean forward. There is a different 2/6
       low-pitched diastolic murmur at the apex.
Pulses are all very prominent and brisk; audible pulse over
the femoral arteries
             Additional Testing
ECG: LVH with massive voltage in the lateral
     precordial leads (V4-V6)
Chest X-Ray: Large heart, predominant left ventricular
      enlargement. No congestive heart failure.
Echo: Marked left ventricular dilation, estimated EF 65%.
      The end diastolic dimension is 65 mm and the end
      diastolic dimension is 55 mm. Aortic valve: bicuspid
      and thickened.
Doppler: Severe aortic regurgitation. The aorta is slightly
  enlarged (4.2 mm).
                                                    *
         Major Causes of Aortic
             Regurgitation
Leaflet Dysfunction        Aortic Root Dilation
Rheumatic fever            Systemic hypertension
Endocarditis               Dissecting aneurysm
Trauma                     Aortitis (syphilis)
Bicuspid aortic valve      Reiter‟s syndrome
Rheumatoid arthritis       Ankylosing spondylitis
Myxomatous degeneration    Ehlers-Danlos
Ankylosing spondylitis     Osteogenesis imperfecta
Marfan‟s syndrome          Pseudoxanthoma elasticum
Fenfluramine-phentermine   Marfan‟s syndrome
Annulo-aortic ectasia
Aortic regurgitation
Physical Findings in Aortic Regurgitation
 Wide pulse pressure:
 Bounding pulses
 Soft aortic second sound (A2)
 Early diastolic murmur (blowing) immediately
  after A2
      Upper RSB with root dilation
      Mid to lower LSB with leaflet dysfunction
 Systolic murmur at base (similar to aortic stenosis)
 Austin Flint murmur: mid to late diastolic
  “rumble” at apex
                                                 *
Some Really Neat Physical Findings in
 Severe Chronic Aortic Regurgitation
 deMusset‟s sign: Head bob with each systolic pulsation
 Corrigans‟s pulses: “Pistol shot” pulses over femoral artery
 Mueller‟s sign: Pulsation of the uvula
 Duroziez‟s sign: Systolic/diastolic bruit over femoral
             artery
 Quincke‟s pulses: Capillary pulsations seen in the
             nailbeds
 Becker‟s sign: Pulsation of retinal arteries and pupils
 Hill‟s sign: Popliteal BP exceeds brachial BP by > 60
              mmHg
Acute vs. chronic aortic
    regurgitation
     Pathophysiology of Chronic
        Aortic Regurgitation
 Slowly progressive diastolic volume overload
 Augmented stroke volume with rapid runoff
     Increased systolic pressure with low
     diastolic pressure: wide pulse pressure
 Progressive left ventricular dilation, some hypertrophy
 Increased diastolic compliance with maintenance of
  normal diastolic pressures initially
 Late systolic failure with reduced ejection fraction and
  CHF
     Acute Aortic Regurgitation
 Sudden diastolic volume overload without LV
  dilation:
      - Acute elevation in left ventricular
        diastolic pressure pulmonary edema
      - Acute LV systolic failure  hypotension

 Provide inotropic support, vasodilator therapy if
  tolerated, urgent valve replacement.
    Natural History of Chronic
      Aortic Regurgitation
 Long asymptomatic phase; may be decades long.
 Left ventricular systolic dysfunction ( decline in
  EF)
      NOTE!! LV dysfunction may occur in the
      absence of symptoms
 Symptoms associated with LV dysfunction:
     - Exercise intolerance
     - Dyspnea on exertion
 Angina (rare)
 Sudden death (rare)
Natural history of aortic
     regurgitation
 Factors Influencing Severity of
     Aortic Regurgitation
Size of regurgitant orifice

Gradient across aortic valve in diastole
 (i.e. worse AR with high diastolic BP)

Duration of diastole
       Management of Chronic
        Aortic Regurgitation
 Close follow up of left ventricular size and function with
  serial echocardiograms (Every few years with mild AR,
  every 6-12 months with severe AR)
 Endocarditis prophylaxis
 Medical therapy:
     Vasodilator therapy: reduces blood pressurereduces
                            regurgitant volume
              Delays need for aortic valve replacement
     Digoxin (enhance systolic function)
     Diuretics (reduce LA pressure)
     Do NOT slow heart rate!
 Aortic valve replacement with mechanical or bioprosthetic
  valve
Criteria for Aortic Valve Replacement in
     Chronic Aortic Regurgitation
   Symptoms
       Congestive heart failure
       Declining exercise tolerance on exercise testing
       Angina

   Anatomy, regardless of symptoms:
       Left ventricular dysfunction: EF <50%
       Progressive left ventricular dilation or decline in
       EF on serial studies
       Severe dilation (echo):
         - Left ventricular diastolic dimension >75 mm
         - Left ventricular systolic dimension >55 mm
       Aortic root dimension >50 mm
  Right Sided Valve Disease:
Read Harrison, 14th Edition: Pages 1322-1323


    Tricuspid stenosis
    Tricuspid regurgitation
    Pulmonic stenosis
    Pulmonic regurgitation