This topic makes several bewildering and thankfully infrequent appearances in the past papers. For example, Question 8.3 from the second paper of 2010 demands the candidates make an assessment of a TTE report, grading the severity of aortic stenosis. In fact, for some reason the college is infatuated with aortic stenosis. It comes up very frequently:

  • Question 16 from the first paper of 2016 (features of severity in chronic aortic regurgitation)
  • Question 29.2 from the second paper of 2008 (severity staging of aortic stenosis)
  • Question 8.3 from the second paper of 2010 (severity staging of aortic stenosis)
  • Question 13.1 from the first paper of 2008 (severity staging of aortic stenosis)

The time-poor candidate can limit their reading to this summary page from ECHOpedia:

If one were in possession of unlimited time resources, the main references for this topic would have to include the following:

A thorough discussion of various valve problems and their haemodynamic consequences takes place in the Mechanical Haemodynamic Support section. The summary below is a more exam-friendly resource.

A dense forest of guidelines and recommendations

The primary source for some of this information should probably be the insanely huge 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease. However, on close inspection their classification is less helpful in answering the CICM questions. Without getting carried away, it suffices to say that the AHA/ACC stages valvular disease in four functional groups, and defines them with possible valve anatomy and TTE findings.

AHA/ACC Stages of Valvular Disease

  • Stage A: At risk of valve disease
  • Stage B: "Progressive"; asymptomatic mild-moderate disease
  • Stage C: Asymptomatic severe disease
  • Stage D: Symptomatic severe disease

Thus, a stage D symptomatic patient with aortic stenosis would have "severe leaflet calcification with severely reduced leaflet motion" on TTE, with an indexed aortic valve area of less than 0.6cm2/m2, and a small LV chamber with low stroke volume. Their symptoms will include syncope and exercise intolerance. This system is generally lauded as being more patient-centric, and cognisant of the destructive remodelling which takes place as a consequence of valve disease.

This system of classification is a major change from the earlier systems, which classified valve disease as mild, moderate or severe. This was the order of the 1998 AHA/ACC guideline statement. Unfortunately, the CICM papers all refer to this older classification. Thus, in order to be relevant both to the past papers and to the potential future questions, this summary ought to offer both systems to the candidate, in order for the past paper answers to make sense.

To complicate issues even further, there is another competing guidelines statement from Europe- the ESC "Guidelines on the Management of Valvular Heart Disease" which have subtle differences in their definition, as if European valves are somehow functionally different to American valves.

In short, there is a ridiculous proliferation of competing guidelines. Committing these numbers to memory is not advised for the CICM candidate. For a vast investment of intellectual resources, the dividend in marks is minimal.

Having said this, it would be nice to have a definitive resource to act as a point of reference.
And if one were to pick one definitive resource, one would have to settle on the 2014 AHA.ACC guidelines, not only because they are the most recent, but also because they incorporate the old "mild-moderate-severe" definitions which the college has used for their model answers.

Thus, the following series of tables are copied directly from the publicly available AHA/ACC guideline statement.

Classification of Aortic Stenosis (AHA/ACC 2014)
Stage
Definition
Valve Anatomy
Valve Hemodynamics
Hemodynamic Consequences
Symptoms
A
At risk of AS
•Bicuspid aortic valve (or other congenital valve anomaly)•Aortic valve sclerosis
•Aortic Vmax <2 m/s
•None
•None
B
Progressive AS
•Mild-to-moderate leaflet calcification of a bicuspid or trileaflet valve with some reduction in systolic motion or•Rheumatic valve changes with commissural fusion
•Mild AS: Aortic Vmax 2.0–2.9 m/s or mean ΔP <20 mm Hg•Moderate AS: Aortic Vmax 3.0–3.9 m/s or mean ΔP 20–39 mm Hg
•Early LV diastolic dysfunction may be present•Normal LVEF
•None
C: Asymptomatic severe AS
C1
Asymptomatic severe AS
•Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening
•Aortic Vmax ≥4 m/s or mean ΔP ≥40 mm Hg•AVA typically is ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2)•Very severe AS is an aortic Vmax ≥5 m/s or mean ΔP ≥60 mm Hg
•LV diastolic dysfunction•Mild LV hypertrophy•Normal LVEF
•None: Exercise testing is reasonable to confirm symptom status
C2
Asymptomatic severe AS with LV dysfunction
•Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening
•Aortic Vmax ≥4 m/s or mean ΔP ≥40 mm Hg•AVA typically ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2)
•LVEF <50%
•None
D: Symptomatic severe AS
D1
Symptomatic severe high-gradient AS
•Severe leaflet calcification or congenital stenosis with severely reduced leaflet opening
•Aortic Vmax ≥4 m/s or mean ΔP ≥40 mm Hg•AVA typically ≤1.0 cm2 (or AVAi ≤0.6 cm2/m2) but may be larger with mixed AS/AR
•LV diastolic dysfunction•LV hypertrophy•Pulmonary hypertension may be present
•Exertional dyspnea or decreased exercise tolerance•Exertional angina•Exertional syncope or presyncope
D2
Symptomatic severe low-flow/low-gradient AS with reduced LVEF
•Severe leaflet calcification with severely reduced leaflet motion
•AVA ≤1.0 cm2 with resting aortic Vmax <4 m/s or mean ΔP <40 mm Hg•Dobutamine stress echocardiography shows AVA ≤1.0 cm2 with Vmax ≥4 m/s at any flow rate
•LV diastolic dysfunction•LV hypertrophy•LVEF <50%
•HF•Angina•Syncope or presyncope
D3
Symptomatic severe low-gradient AS with normal LVEF or paradoxical low-flow severe AS
•Severe leaflet calcification with severely reduced leaflet motion
•AVA ≤1.0 cm2 with aortic Vmax <4 m/s or mean ΔP <40 mm Hg•Indexed AVA ≤0.6 cm2/m2 and•Stroke volume index <35 mL/m2•Measured when patient is normotensive (systolic BP <140 mm Hg)
•Increased LV relative wall thickness•Small LV chamber with low stroke volume•Restrictive diastolic filling•LVEF ≥50%
•HF•Angina•Syncope or presyncope
Classification of Chronic Aortic Regurgitation (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms
A At risk of AR •Bicuspid aortic valve (or other congenital valve anomaly)•Aortic valve sclerosis•Diseases of the aortic sinuses or ascending aorta•History of rheumatic fever or known rheumatic heart disease•IE •AR severity: none or trace •None •None
B Progressive AR •Mild-to-moderate calcification of a trileaflet valve bicuspid aortic valve (or other congenital valve anomaly)•Dilated aortic sinuses•Rheumatic valve changes•Previous IE •Mild AR:○Jet width <25% of LVOT;○Vena contracta <0.3 cm;○RVol <30 mL/beat;○RF <30%;○ERO <0.10 cm2;○Angiography grade 1+•Moderate AR:○Jet width 25%–64% of LVOT;○Vena contracta 0.3–0.6 cm;○RVol 30–59 mL/beat;○RF 30%–49%;○ERO 0.10–0.29 cm2;○Angiography grade 2+ •Normal LV systolic function•Normal LV volume or mild LV dilation •None
C Asymptomatic severe AR •Calcific aortic valve disease•Bicuspid valve (or other congenital abnormality)•Dilated aortic sinuses or ascending aorta•Rheumatic valve changes•IE with abnormal leaflet closure or perforation •Severe AR:○Jet width ≥65% of LVOT;○Vena contracta >0.6 cm;○Holodiastolic flow reversal in the proximal abdominal aorta○RVol ≥60 mL/beat;○RF ≥50%;○ERO ≥0.3 cm2;○Angiography grade 3+ to 4+;○In addition, diagnosis of chronic severe AR requires evidence of LV dilation C1: Normal LVEF (≥50%) and mild-to-moderate LV dilation (LVESD ≤50 mm)C2: Abnormal LV systolic function with depressed LVEF (<50%) or severe LV dilatation (LVESD >50 mm or indexed LVESD >25 mm/m2) •None; exercise testing is reasonable to confirm symptom status
D Symptomatic severe AR •Calcific valve disease•Bicuspid valve (or other congenital abnormality)•Dilated aortic sinuses or ascending aorta•Rheumatic valve changes•Previous IE with abnormal leaflet closure or perforation •Severe AR:○Doppler jet width ≥65% of LVOT;○Vena contracta >0.6 cm,○Holodiastolic flow reversal in the proximal abdominal aorta,○RVol ≥60 mL/beat;○RF ≥50%;○ERO ≥0.3 cm2;○Angiography grade 3+ to 4+;○In addition, diagnosis of chronic severe AR requires evidence of LV dilation •Symptomatic severe AR may occur with normal systolic function (LVEF ≥50%), mild-to-moderate LV dysfunction (LVEF 40%–50%), or severe LV dysfunction (LVEF <40%);•Moderate-to-severe LV dilation is present. •Exertional dyspnea or angina or more severe HF symptoms
Classification of Mitral Stenosis (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms
A At risk of MS •Mild valve doming during diastole •Normal transmitral flow velocity •None •None
B Progressive MS •Rheumatic valve changes with commissural fusion and diastolic doming of the mitral valve leaflets•Planimetered MVA >1.5 cm2 •Increased transmitral flow velocities•MVA >1.5 cm2•Diastolic pressure half-time <150 ms •Mild-to-moderate LA enlargement•Normal pulmonary pressure at rest •None
C Asymptomatic severe MS •Rheumatic valve changes with commissural fusion and diastolic doming of the mitral valve leaflets•Planimetered MVA ≤1.5 cm2•(MVA ≤1.0 cm2 with very severe MS) •MVA ≤1.5 cm2•(MVA ≤1.0 cm2 with very severe MS)•Diastolic pressure half-time ≥150 ms•(Diastolic pressure half-time ≥220 ms with very severe MS) •Severe LA enlargement•Elevated PASP >30 mm Hg •None
D Symptomatic severe MS •Rheumatic valve changes with commissural fusion and diastolic doming of the mitral valve leaflets•Planimetered MVA ≤1.5 cm2 •MVA ≤1.5 cm2•(MVA ≤1.0 cm2 with very severe MS)•Diastolic pressure half-time ≥150 ms•(Diastolic pressure half-time ≥220 ms with very severe MS) •Severe LA enlargement•Elevated PASP >30 mm Hg

•Decreased exercise tolerance

•Exertional dyspnea

Classification of Primary Mitral Regurgitation (AHA/ACC 2014)
Grade Definition Valve Anatomy Valve Hemodynamics∗ Hemodynamic Consequences Symptoms
A At risk of MR •Mild mitral valve prolapse with normal coaptation•Mild valve thickening and leaflet restriction •No MR jet or small central jet area <20% LA on Doppler•Small vena contracta <0.3 cm •None •None
B Progressive MR •Severe mitral valve prolapse with normal coaptation•Rheumatic valve changes with leaflet restriction and loss of central coaptation•Prior IE •Central jet MR 20%–40% LA or late systolic eccentric jet MR•Vena contracta <0.7 cm•Regurgitant volume <60 mL•Regurgitant fraction <50%•ERO <0.40 cm2•Angiographic grade 1–2+ •Mild LA enlargement•No LV enlargement•Normal pulmonary pressure •None
C Asymptomatic severe MR •Severe mitral valve prolapse with loss of coaptation or flail leaflet•Rheumatic valve changes with leaflet restriction and loss of central coaptation•Prior IE•Thickening of leaflets with radiation heart disease •Central jet MR >40% LA or holosystolic eccentric jet MR•Vena contracta ≥0.7 cm•Regurgitant volume ≥60 mL•Regurgitant fraction ≥50%•ERO ≥0.40 cm2•Angiographic grade 3–4+ •Moderate or severe LA enlargement•LV enlargement•Pulmonary hypertension may be present at rest or with exercise•C1: LVEF >60% and LVESD <40 mm•C2: LVEF ≤60% and LVESD ≥40 mm •None
D Symptomatic severe MR •Severe mitral valve prolapse with loss of coaptation or flail leaflet•Rheumatic valve changes with leaflet restriction and loss of central coaptation•Prior IE•Thickening of leaflets with radiation heart disease •Central jet MR >40% LA or holosystolic eccentric jet MR•Vena contracta ≥0.7 cm•Regurgitant volume ≥60 mL•Regurgitant fraction ≥50%•ERO ≥0.40 cm2•Angiographic grade 3–4+ •Moderate or severe LA enlargement•LV enlargement•Pulmonary hypertension present

•Decreased exercise tolerance

•Exertional dyspnea

Classification of Secondary Mitral Regurgitation (AHA/ACC 2014)
Grade Definition Valve Anatomy Valve Hemodynamics∗ Associated Cardiac Findings Symptoms
A At risk of MR •Normal valve leaflets, chords, and annulus in a patient with coronary disease or cardiomyopathy •No MR jet or small central jet area <20% LA on Doppler•Small vena contracta <0.30 cm •Normal or mildly dilated LV size with fixed (infarction) or inducible (ischemia) regional wall motion abnormalities•Primary myocardial disease with LV dilation and systolic dysfunction •Symptoms due to coronary ischemia or HF may be present that respond to revascularization and appropriate medical therapy
B Progressive MR •Regional wall motion abnormalities with mild tethering of mitral leaflet•Annular dilation with mild loss of central coaptation of the mitral leaflets •ERO <0.20 cm2†•Regurgitant volume <30 mL•Regurgitant fraction <50% •Regional wall motion abnormalities with reduced LV systolic function•LV dilation and systolic dysfunction due to primary myocardial disease •Symptoms due to coronary ischemia or HF may be present that respond to revascularization and appropriate medical therapy
C Asymptomatic severe MR •Regional wall motion abnormalities and/or LV dilation with severe tethering of mitral leaflet•Annular dilation with severe loss of central coaptation of the mitral leaflets •ERO ≥0.20 cm2†•Regurgitant volume ≥30 mL•Regurgitant fraction ≥50% •Regional wall motion abnormalities with reduced LV systolic function•LV dilation and systolic dysfunction due to primary myocardial disease •Symptoms due to coronary ischemia or HF may be present that respond to revascularization and appropriate medical therapy
D Symptomatic severe MR •Regional wall motion abnormalities and/or LV dilation with severe tethering of mitral leaflet•Annular dilation with severe loss of central coaptation of the mitral leaflets •ERO ≥0.20 cm2†•Regurgitant volume ≥30 mL•Regurgitant fraction ≥50% •Regional wall motion abnormalities with reduced LV systolic function•LV dilation and systolic dysfunction due to primary myocardial disease

•HF symptoms due to MR persist even after revascularization and optimization of medical therapy

Decreased exercise tolerance

Exertional dyspnea

Classification of Tricuspid Regurgitation (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics∗ Hemodynamic Consequences Symptoms
A At risk of TR Primary•Mild rheumatic change•Mild prolapse•Other (e.g., IE with vegetation, early carcinoid deposition, radiation)•Intra-annular RV pacemaker or ICD lead•Postcardiac transplant (biopsy related)Functional•Normal•Early annular dilation •No or trace TR •None •None or in relation to other left heart or pulmonary/pulmonary vascular disease
B Progressive TR Primary•Progressive leaflet deterioration/destruction•Moderate-to-severe prolapse, limited chordal ruptureFunctional•Early annular dilation•Moderate leaflet tethering Mild TR•Central jet area <5.0 cm2•Vena contracta width not defined•CW jet density and contour: soft and parabolic•Hepatic vein flow: systolic dominanceModerate TR•Central jet area 5–10 cm2•Vena contracta width not defined but <0.70 cm•CW jet density and contour: dense, variable contour•Hepatic vein flow: systolic blunting Mild TR•RV/RA/IVC size normalModerate TR•No RV enlargement•No or mild RA enlargement•No or mild IVC enlargement with normal respirophasic variation•Normal RA pressure •None or in relation to other left heart or pulmonary/pulmonary vascular disease
C Asymptomatic, severe TR Primary•Flail or grossly distorted leafletsFunctional•Severe annular dilation (>40 mm or 21 mm/m2)•Marked leaflet tethering •Central jet area >10.0 cm2•Vena contracta width >0.7 cm•CW jet density and contour: dense, triangular with early peak•Hepatic vein flow: systolic reversal •RV/RA/IVC dilated with decreased IVC respirophasic variation•Elevated RA pressure with “c-V” wave•Diastolic interventricular septal flattening may be present •None, or in relation to other left heart or pulmonary/pulmonary vascular disease
D Symptomatic severe TR Primary•Flail or grossly distorted leafletsFunctional•Severe annular dilation (>40 mm or >21 mm/m2)•Marked leaflet tethering •Central jet area >10.0 cm2•Vena contracta width >0.70 cm•CW jet density and contour: dense, triangular with early peak•Hepatic vein flow: systolic reversal •RV/RA/IVC dilated with decreased IVC respirophasic variation•Elevated RA pressure with “c-V” wave•Diastolic interventricular septal flattening•Reduced RV systolic function in late phase •Fatigue, palpitations, dyspnea, abdominal bloating, anor
Classification of Tricuspid Stenosis (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms
C, D Severe TS •Thickened, distorted, calcified leaflets •T ½ ≥190 ms•Valve area ≤1.0 cm2 •RA/IVC enlargement •None or variable and dependent on severity of associated valve disease and degree of obstruction

The statement reports: "The transtricuspid diastolic gradient is highly variable and is affected by heart rate, forward flow, and phases of the respiratory cycle. However, severe TS usually has mean pressure gradients >5 to 10 mm Hg at heart rate 70 bpm."

Classification of Pulmonary Regurgitation (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms
C, D Severe PR •Distorted or absent leaflets, annular dilation •Color jet fills RVOT•CW jet density and contour: dense laminar flow with steep deceleration slope; may terminate abruptly •Paradoxical septal motion (volume overload pattern)•RV enlargement •None or variable and dependent on cause of PR and RV function
Classification of Pulmonic Stenosis (AHA/ACC 2014)
Stage Definition Valve Anatomy Valve Hemodynamics Hemodynamic Consequences Symptoms
C, D Severe PS •Thickened, distorted, possibly calcified leaflets with systolic doming and/or reduced excursion•Other anatomic abnormalities may be present, such as narrowed RVOT •Vmax >4 m/s; peak instantaneous gradient >64 mm Hg •RVH•Possible RV, RA enlargement•Poststenotic enlargement of main PA •None or variable and dependent on severity of obstruction