II. Epidemiology

  1. Prevalence: 3% of those over age 65 years old in U.S.
  2. Most significant cardiac valve disorder in the developed world

III. Etiology

  1. Congenital Bicuspid Valve (Most common)
    1. Twice as common in men
    2. Slow increase in stenosis (progressive sclerosis)
      1. Childhood: mild stenosis and asymptomatic
      2. Ages 20-40: moderate stenosis develops
      3. Over age 40: severe stenosis develops
  2. Atherosclerosis
    1. Normal aortic tricuspid valve becomes calcified and rigid with age
    2. Gradually develops, typically presenting over age 70 years
    3. Rarely severe
  3. Rheumatic Fever
    1. Slowly progressive stenosis
  4. Subacute Bacterial Endocarditis

IV. Pathophysiology: Course

  1. Initial: Long asymptomatic latent period
  2. Course
    1. Increased left ventricular outflow obstruction and flow restriction
      1. Increased left ventricular pressures
    2. Next: Left Ventricular Hypertrophy (left ventricular wall thickening with preserved LV volume)
    3. Next: Diastolic Dysfunction (resistance to LV filling with preserved systolic function)
    4. Next: Systolic Dysfunction and Congestive Heart Failure
    5. Next: Increased myocardial oxygen demand, Coronary Artery compression and secondary Angina
    6. Next: Hypotension and Syncope in response to Exercise

V. Symptoms

  1. Mild to Moderate stenosis
    1. Asymptomatic
  2. Severe Obstruction
    1. Dyspnea (most common presenting symptom)
      1. Dyspnea on exertion progresses to Dyspnea at rest
    2. Other presenting symptoms
      1. Syncope
      2. Exercise induced Angina
      3. Congestive Heart Failure

VI. Signs

  1. Classic Murmur
    1. Harsh, late-peaking, crescendo-decrescendo Systolic Murmur
    2. Medium pitch
    3. Heard best at right upper Sternum (second intercostal space)
    4. May also be heard at apex (esp. elderly)
    5. May radiate into Carotid Artery region
  2. Mild Aortic Stenosis
    1. Loud ejection click (best heard at apex)
    2. Short, early Systolic Murmur (at right second intercostal space)
    3. Loud A2 heart sound (best heard at aortic area)
  3. Moderate Aortic Stenosis
    1. Ejection click (best heard at apex)
    2. Early Systolic Murmur (loudest at right second intercostal space)
      1. Transmitted to Supraclavicular, Carotids, Apex
      2. Harsh
      3. Systolic ejection murmur that peaks later in systole
      4. Ends well before A2 heart sound
    3. Arterial Pulse altered
      1. Upstroke of the pulse has shudder
      2. Delayed, prolonged, low-volume carotid pulsation (Pulsus parvus et tardus)
        1. Test Sensitivity 70% and Test Specificity 98% in Aortic Stenosis
        2. Roldan (1996) Am J Cardiol 77(15): 1327-31 [PubMed]
    4. Apex impulse may be abnormal, accentuated
      1. Slightly sustained
      2. Presystolic Shoulder ("a wave") precedes major systolic impulse
    5. Systolic thrill may be palpated at base
    6. S4 Gallup Rhythm
  4. Severe Aortic Stenosis
    1. Ejection click NO longer present
    2. A2 heart sound is markedly diminished
    3. Systolic Murmur
      1. Variable loudness (may be quiet despite severity)
      2. Long, nearly holosystolic
      3. Harsh (especially at aortic area)
    4. Carotid pulse very abnormal
      1. Very slow and long upstroke (Pulsus parvus et tardus)
      2. Overall very weak pulse
    5. Brachioradial delay
      1. Right brachial pulse and right radial pulse are simultaneously palpated
      2. Radial pulse is felt after the brachial pulse in severe Aortic Stenosis (also in MR with severe CHF)
        1. Leach (1990) Lancet 335(8699):1199-201 [PubMed]
    6. Apical impulse abnormal
      1. Strong and sustained for all of systole

VII. Signs: Most significant findings

  1. Precautions
    1. Pulse changes may be masked by atherosclerosis or Hypertension
    2. Murmur may be less prominent with reduced LV function
    3. Murmur may radiate to apex but not carotids in elderly
  2. High Positive Likelihood Ratio (rule-in diagnosis)
    1. Pulsus parvus et tardus (low pulse volume and slow rate of rise of carotid or brachial pulse)
  3. Low Negative Likelihood Ratio (most likely to rule-out diagnosis)
    1. Absence of late peaking murmur (early peaking murmur is typically benign)
    2. Lack of radiation to right carotid or clavicle
    3. Normally split Second Heart Sound (S2)

VIII. Classification: Aortic Stenosis Severity

  1. Aortic jet velocity (transaortic velocity)
    1. Normal: <2.0 m/sec
    2. Mild: 2.0 to 2.9 m/sec
    3. Moderate: 3.0 to 3.9 m/sec
    4. Severe: >4.0 m/sec
  2. Mean pressure gradient
    1. Normal: <10 mmHg
    2. Mild: 10-20 mmHg
    3. Moderate: 20-40 mmHg
    4. Severe: >40 mmHg
    5. Critical: >50 mmHg
  3. Aortic valve area
    1. Normal: 3 to 4 cm2
    2. Mild: 1.5 to 2 cm2
    3. Moderate: 1 to 1.5 cm2
    4. Severe: <1 cm2
    5. Critical: <0.8 cm2

IX. Associated Conditions

  1. AV Node Block (often concurrent with Aortic Stenosis)
  2. Aortic Coarctation
  3. Aortic Dissection

X. Diagnotics: Electrocardiogram

  1. Precautions
    1. Electrocardiogram may only be abnormal in moderate to severe Aortic Stenosis
  2. Common findings
    1. Left Ventricular Hypertrophy
      1. Peak systolic gradient (PSG) has been correlated to the QRS amplitude (LVH criteria)
      2. Kishore (1990) Indian Heart J 42(1): 62-5 [PubMed]
  3. Other findings
    1. T Wave reduction in leads I, avL, V5, V6
    2. Left Anterior Hemiblock or Left Bundle Branch Block
    3. Complete AV Block

XI. Imaging

  1. Chest XRay
    1. Precautions
      1. Chest XRay is a low yield test in Aortic Stenosis diagnosis
      2. Chest XRay is primarily used to evaluate presenting symptoms (Dyspnea, Syncope, Chest Pain)
    2. Findings (unreliable)
      1. Apical Contour abnormal suggests large left ventricle
      2. Prominent ascending aorta
      3. Aortic valve calcification
  2. Echocardiogram
    1. Most important study in the evaluation of suspected Aortic Stenosis
    2. Frequency
      1. Initial presentation
      2. Once Aortic Stenosis is diagnosed, repeat echo per monitoring schedule based on severity (see below)
    3. Indications
      1. Loud (grade 3), unexplained Systolic Murmur (esp. holosystolic, late systolic)
      2. Single Second Heart Sound
      3. History of bicuspid aortic valve
      4. Symptoms suggestive of Aortic Stenosis
      5. New murmur associated with new symptom presentation (Dyspnea, Syncope, Angina)
    4. Findings
      1. Aortic Stenosis diagnosis
        1. Aortic Stenosis grading with aortic valve gradient, orifice size, jet velocity
        2. Aortic Stenosis complications (LV hypertrophy, Diastolic Dysfunction, Systolic Dysfunction)
      2. Other aortic valve disorders
        1. Bicuspid valve
        2. Mildly obstructed valve
        3. Thickened, sclerotic valve
      3. Other valve disorders presenting similarly to Aortic Stenosis (Dyspnea, Syncope, Angina)
        1. Acute Mitral Regurgitation (especially due to Myocardial Infarction with papillary Muscle rupture)
        2. Prosthetic valve disorders (e.g. valvular regurgitation or obstruction)
  3. Cardiac Catheterization (Angiogram)
    1. Can directly measure left ventricular pressure gradient

XII. Differential Diagnosis

  1. Supravalvular Aortic Stenosis
  2. Membranous supravalvular Aortic Stenosis
  3. Hypertrophic Cardiomyopathy (IHSS)
  4. Mitral Regurgitation

XIII. Management: General Measures

  1. Asymptomatic Aortic Stenosis progression is not prevented by any specific measures
  2. SBE Prophylaxis is no longer recommended (until aortic Valve Replacement, or history of prior endocarditis)
  3. Manage comorbid conditions
  4. Avoid strenuous Exercise or activity in moderate to severe Aortic Stenosis
    1. Limit activity in high Dynamic Sports and high Static Sports
    2. No restriction needed for mild Aortic Stenosis
  5. Reduce cardiovascular risk
    1. See Cardiac Risk Management
    2. Tobacco Cessation
    3. Consider Aspirin prophylaxis
    4. Consider Statin for lipid lowering
    5. Control Hypertension (40% of patients)
      1. ACE Inhibitors
      2. Amlodipine (Norvasc)
      3. Diuretics (slowly titrate from low dose)
      4. Avoid peripheral alpha blockers (risk of Syncope)
  6. Manage comorbid Atrial Fibrillation (5% of patients) with rate control
    1. See Atrial Fibrillation Rate Control
    2. Use with caution Beta Blockers and Calcium Channel Blockers
      1. Risk of exacerbating Left Ventricular Systolic Dysfunction

XIV. Management: Symptomatic and severe stenosis (>40 mmHg across valve or aortic jet velocity >4.0 m/s)

  1. Admit symptomatic severe Aortic Stenosis and plan aortic Valve Replacement
  2. Preferred agents
    1. ACE Inhibitors
    2. Amlodipine (Norvasc)
    3. Nitroprusside
      1. Consider in critical Aortic Stenosis and ejection fraction <35%
      2. Khot (2003) N Engl J Med 348(18): 1756-63 [PubMed]
  3. Agents to use with caution
    1. Diuretics
      1. Indicated for Congestive Heart Failure
      2. Use with caution (lowers LV filling pressure)
    2. Use Nitroglycerin only with caution
      1. Monitor Blood Pressure carefully
      2. Volume expansion may be required
    3. Use Beta Blockers with caution
      1. Risk of Congestive Heart Failure
  4. Agents to avoid
    1. Peripheral Alpha Adrenergic Antagonists

XV. Management: Aortic Valve Replacement Indications

  1. Synopsis
    1. Aortic valve area <1 cm2 is criteria for stenosis unless completely normal cardiovascular testing
  2. Criteria 1: Severe Aortic Stenosis (see classification above) and
    1. Aortic jet velocity: >4 m/sec
    2. Mean gradient: >40 mmHg
    3. Aortic valve area: <1 cm2
  3. Criteria 2: One of criteria below
    1. Symptomatic Aortic Stenosis
    2. Possible symptomatic Aortic Stenosis (esp. elderly) with abnormal stress test
      1. Symptoms or Hypotension
      2. Left Ventricular ejection fraction <50%
      3. Dobutamine Stress Echo with <=1 cm valve area or aortic jet velocity >=4 m/s
    3. Heart Surgery (e.g. CABG) is already planned (consider AVR even if moderate Aortic Stenosis)
    4. Left ventricular ejection fraction <50%
    5. Severe aortic valve calcification or rapid progression (e.g. 0.3 m/s increase per year)
    6. Low-flow, low gradient severe Aortic Stenosis may initially be misdiagnosed as moderate Aortic Stenosis
      1. Most common in older women with Hypertension
    7. Asymptomatic but near critical Aortic Stenosis
      1. Aortic valve gradient >60 mmHg
      2. Aortic valve orifice <0.6 cm2
      3. Aortic jet velocity >5.0 m/s
      4. Nishimura (2005) Mayo Reviews Lecture, Rochester

XVI. Precautions: Surgical evaluation should be prompt for severe Aortic Stenosis

  1. Do not Exercise Stress Test severe Aortic Stenosis with symptoms (high risk for adverse events)
    1. Consider stress test only if symptomatic status is unclear
  2. Risk of sudden death
  3. Valve Replacement may be indicated even if ejection fraction low
  4. Valve Replacement is not effective if low ejection fraction and low valve gradient
  5. Carabello (2002) N Engl J Med 346:677-82 [PubMed]

XVII. Complications

XVIII. Monitoring: Echocardiogram Frequency

  1. Mild Aortic Stenosis: Every 3-5 years
  2. Moderate Aortic Stenosis: Every 1-2 years
  3. Severe Aortic Stenosis: Every 6-12 months

XIX. Prognosis: Prior to Valve Replacement

  1. Mild Aortic Stenosis: Good (slow progression)
    1. Anticipate active and asymptomatic for 10-50 years
  2. Asymptomatic severe Aortic Stenosis
    1. At 5 years, 72% will die or have symptoms
    2. Recent data suggests sudden death rate is high
    3. Pellikka (2005) Circulation 111:3290-5 [PubMed]
  3. Symptomatic severe Aortic Stenosis: Poor prognosis
    1. Most patients will have symptom progression
    2. Anticipate death within 3 years in most patients
    3. Even mild pre-AVR symptoms predict a 2 year mortality >50%

XX. Prognosis: After Aortic Valve Replacement

  1. Consider transcatheter Valve Replacement in those who are at very high surgical risk
  2. Mortality at 30 days post-AVR: 3% (up to 4.5% if CABG performed at the same time)

XXI. Resources

  1. Late Aortic Stenosis (University of Washington School of Medicine)
    1. https://depts.washington.edu/physdx/audio/lateas.mp3

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Aortic Valve Stenosis (C0003507)

Definition (NCI) Narrowing of the orifice of the aortic valve or of the supravalvular or subvalvular regions.
Definition (NCI_FDA) Narrowing of the orifice of the aortic valve or of the supravalvular or subvalvular regions.
Definition (CSP) constriction in the opening of the aortic valve or of the supravalvular or subvalvular regions.
Definition (MSH) A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Concepts Disease or Syndrome (T047)
MSH D001024
ICD10 I35.0 , Q25.3
SnomedCT 390722003, 60573004
English Aortic Stenosis, Aortic Valve Stenoses, Aortic Valve Stenosis, Stenoses, Aortic, Stenoses, Aortic Valve, Valve Stenoses, Aortic, Valve Stenosis, Aortic, AORTIC VALVE STENOSIS, Stenosis, Aortic, Stenosis, Aortic Valve, AORTIC VALVULAR STENOSIS, Aortic (valve) stenosis, Stenosis of aorta, Valvular aortic stenosis, Stenosis aortic valve, Aortic Valve Stenosis [Disease/Finding], aortic valvular stenosis, aortic valvular stenosis (diagnosis), Stenosis;aortic, stenosis aorta, stenosis aortic, stenose aortic, stenosis - aortic, aortic valve stenosis, aorta stenosis, Stenosis of aortic valve, Aortic stenosis (disorder), Aortic valve--Stenosis, AORTIC STENOSIS, Aortic stenosis, Aortic valve stenosis, AS - Aortic stenosis, Stenosed aortic valve, Aortic valve stenosis (disorder), stenosis; aortic valve, aorta; stenosis, valve, aortic valve; stenosis, aortic valve; stricture, Aortic valve stenosis, NOS, aortic stenosis
French STENOSE AORTIQUE VALVULAIRE, Sténose valvulaire aortique, Rétrecissement valvulaire aortique, STENOSE DE L'AORTE, Sténose aortique, Sténose de la valve aortique, Rétrécissement aortique, Rétrécissement aortique valvulaire, Sténose aortique valvulaire
German AORTENKLAPPENSTENOSE, Stenose Aortenklappe, AORTENSTENOSE, Stenose der Aorta (angeboren), Aortenklappenstenose, Aortenstenose
Portuguese ESTENOSE AORTICA, ESTENOSE VALVULAR AORTICA, Estenose da aorta, Estenose da válvula aórtica, Estenose Aórtica, Estenose da Valva Aórtica
Spanish ESTENOSIS AORTICA, ESTENOSIS VALVULA AORTICA, estenosis de la válvula aórtica (trastorno), estenosis de la válvula aórtica, Estenosis de la válvula aórtica, Estenosis valvular aórtica, Estenosis Aórtica, Estenosis de la Válvula Aórtica
Italian Stenosi valvolare aortica, Stenosi della valvola aortica, Stenosi aortica
Japanese 大動脈狭窄, ダイドウミャクベンキョウサク, ダイドウミャクキョウサク, 大動脈弁狭窄症, 大動脈弁狭窄
Swedish Aortaklafförträngning
Finnish Aorttaläpän ahtauma
Czech Stenóza aortální chlopně, Stenóza aorty, aortální chlopeň - stenóza, aortální stenóza
Korean 대동맥 협착, 대동맥(판) 협착증
Polish Zwężenie aorty, Zwężenie zastawki aortalnej, Zwężenie aortalne, Zwężenie ujścia aorty, Stenoza aortalna, Zwężenie zastawki aorty
Hungarian Aortabillentyű-szűkület, Aorta billentyű stenosis, Aorta stenosis
Norwegian Aortastenose
Dutch aorta; stenose, klep, aortaklep; stenose, aortaklep; strictuur, stenose; aortaklep, Aorta(klep)stenose, Stenose van aorta, aortaklepstenose, aortastenose, Aortaklepstenose, Aortastenose, Stenose, aortaklep-