clozeII.A-001
Severe aortic stenosis by 2020 ACC/AHA: peak jet velocity ≥ 4.0 m/s, mean gradient ≥ 40 mmHg, AVA ≤ 1.0 cm².
basicII.A-002
State the continuity equation for aortic valve area.
→ AVA = (CSA_LVOT × VTI_LVOT) / VTI_AV = (0.785 × d²_LVOT × VTI_LVOT) / VTI_AV.
basicII.A-003
Where in the cardiac cycle and where anatomically is the LVOT diameter measured?
→ Mid-systole, inner-edge to inner-edge, in the parasternal long-axis view, at the annulus level.
basicII.A-004
Where do you place the LVOT PW sample volume for the continuity equation?
→ Approximately 2–3 mm proximal to the aortic valve. Presence of an aortic valve closing click on the trace indicates the sample volume is very close to the valve.
clozeII.A-005
The dimensionless velocity index (VTI_LVOT / VTI_AV) is severe AS if ≤ 0.25. Its main advantage is being flow-independent.
basicII.A-006
When must you use the full form of the Bernoulli equation for AS?
→ When LVOT velocity (v₁) > 1.5 m/s, or when AV velocity (v₂) < 3 m/s. Then ΔP = 4(v₂² − v₁²) rather than the simplified 4v².
basicII.A-007
How do the AS mean gradient and peak gradient relate?
→ Mean gradient ≈ 0.6 × peak gradient (or approximately 2.4 × V_max²).
basicII.A-008
When comparing Doppler and cath gradients in AS, which values should be compared?
→ Mean gradients only. Peak-to-peak cath gradient has no physiologic equivalent on Doppler. Peak instantaneous cath and Doppler gradients also do not occur at the same instant.
basicII.A-009
Why is the catheter-measured gradient typically LOWER than the Doppler mean gradient in AS?
→ Pressure recovery — downstream of the vena contracta some kinetic energy is reconverted to pressure. Doppler measures at the vena contracta (maximum gradient); cath measures a few cm downstream after recovery.
basicII.A-010
In which patients is pressure recovery clinically significant?
→ Moderate–severe AS with AVA ~0.9–1.2 cm² and a SMALL ascending aorta (diameter < 30 mm). Smaller aorta → more recovery → lower cath gradient / larger effective valve area.
basicII.A-011
Give three factors that transiently INCREASE the transaortic gradient without a true change in AS severity.
→ Anxiety, exercise, hyperdynamic state, concomitant AI, tachycardia — anything that raises stroke volume or transvalvular flow.
basicII.A-012
Give three factors that transiently DECREASE the transaortic gradient in true severe AS.
→ Sedation, hypovolemia, significant MR, low EF, LVH with small cavity — anything reducing forward stroke volume.
basicII.A-013
How is 'true-severe' distinguished from 'pseudo-severe' AS in low-flow, low-gradient AS with reduced EF?
→ Low-dose dobutamine stress echo. True-severe: peak velocity > 4 m/s (or MG > 40) with AVA < 1 cm² at peak dose. Pseudo-severe: AVA increases > 1 cm² with augmented flow.
basicII.A-014
What defines contractile (flow) reserve on dobutamine stress echo in AS?
→ ≥ 20 % increase in stroke volume. Absent flow reserve is a poor prognostic sign — 30-day SAVR mortality 8–30 % vs 5–8 % with reserve.
basicII.A-015
Define paradoxical low-flow, low-gradient severe AS.
→ EF ≥ 50 %, AVA ≤ 1 cm², but mean gradient < 40 mmHg, with low stroke-volume index < 35 mL/m². Typical patient: elderly, hypertensive, female, small LV cavity, LVH, high SVR.
basicII.A-016
When should you use aortic valve calcium scoring (CT) to confirm severe AS?
→ When there is discordance between AVA and gradient/velocity — especially in paradoxical low-flow low-gradient AS. Severe if calcium ≥ 2000 AU (men) or ≥ 1200 AU (women).
basicII.A-017
How often should severe asymptomatic AS be re-imaged if not going for AVR?
→ TTE every 6–12 months.
basicII.A-018
What is a 'raphe' in a bicuspid aortic valve? Why is systole the key phase for identification?
→ A raphe is a fibrous ridge from congenital fusion of two commissures. A BAV with a raphe can appear trileaflet in diastole; only systole (with maximal opening) reveals only two functional cusps.
basicII.A-019
What is the most common bicuspid aortic valve phenotype?
→ Fusion of the right coronary and left coronary cusps (RCC–LCC) — anterior + posterior leaflets, horizontal closure line. Present in ~70 %.
basicII.A-020
Which BAV fusion pattern carries the highest risk of aortic dilation?
→ RCC–NCC fusion (20–30 %). Associated with greater aortopathy than the more common RCC–LCC fusion.
basicII.A-021
Two classic non-aortic-valve associations with a bicuspid aortic valve?
→ Coarctation of the aorta and intracranial (berry) aneurysms. Also: ~20–30 % of first-degree relatives have BAV.
basicII.A-022
What defines BAV aortopathy dimensions?
→ Aortic root ≥ 40 mm or ascending aorta ≥ 37 mm are considered abnormal. Growth rate typically 0.4–0.6 mm/year.
basicII.A-023
How does rheumatic AV disease look on echo?
→ Commissural fusion with systolic doming and leaflet thickening; TRIANGULAR AV opening in systole. Usually with concurrent mitral involvement.
basicII.A-024
How does senile calcific AS differ from rheumatic AS morphologically?
→ Senile: fibrocalcific masses on the aortic side of leaflets with increased stiffness but NO commissural fusion. Rheumatic: commissural fusion. Avoid direct planimetry with heavy calcification.
basicII.A-025
List the criteria for SEVERE aortic regurgitation.
→ Vena contracta > 0.6 cm; color jet width > 65% of LVOT; regurgitant volume > 60 mL; regurgitant fraction > 50%; EROA > 0.30 cm²; PHT < 200 ms; holodiastolic flow reversal in the proximal abdominal/descending aorta.
basicII.A-026
Why is a short pressure half-time (PHT < 200 ms) a marker of severe AR?
→ Rapid decline of the CW velocity slope reflects rapid equalization of aortic and LV diastolic pressures — indicating large regurgitant volume across the valve.
basicII.A-027
Give three echo findings distinguishing ACUTE from chronic severe AR.
→ Acute: LV NOT dilated (no time to remodel); EARLY mitral valve closure before QRS; early AV opening; fluttering of AMVL. Chronic: LV dilation, wide pulse pressure, increased E-point septal separation.
basicII.A-028
Name three causes of ACUTE severe AR.
→ Endocarditis, aortic dissection, blunt chest trauma.
basicII.A-029
What is the most common cause of MILD aortic regurgitation?
→ Hypertension.
basicII.A-030
Which volumetric measurement should NOT be used for cardiac output in significant AR, and what should be used instead?
→ Do NOT use LVOT stroke volume (falsely elevated by regurgitant volume). Use mitral inflow-derived stroke volume (if the mitral valve is competent).
basicII.A-031
Where is aortic flow reversal best interrogated on TTE for AR grading?
→ The suprasternal notch view of the descending aorta (or the subcostal window for the proximal abdominal aorta). Holodiastolic flow reversal = severe AR (analogous to Duroziez's sign).
basicII.A-032
List three causes of false-positive holodiastolic aortic flow reversal (mimics severe AR).
→ Patent ductus arteriosus (PDA); left-arm arteriovenous fistula (e.g., dialysis fistula); stiff vasculature from long-standing hypertension.
basicII.A-033
Estimating LV end-diastolic pressure from an AR CW jet — how?
→ LVEDP = Aortic end-diastolic BP − end-diastolic pressure gradient (from CW AR jet, using Bernoulli: 4 × [end-diastolic velocity]²). Normal LVEDP ≈ 10–12 mmHg.
basicII.A-034
List three conditions commonly associated with a subaortic membrane.
→ VSD, PDA, coarctation, Shone complex, bicuspid AV, persistent left SVC, and pulmonic valve stenosis.
basicII.A-035
When is subaortic membrane resection indicated?
→ When at least moderate aortic regurgitation is present (jet damage progresses); in a young patient with a non-calcified AV, repair is favored over replacement.
basicII.A-036
What congenital syndrome typically causes supravalvular aortic stenosis?
→ Williams syndrome (elastin gene deletion, 7q11.23). Often with supravalvular PS and peripheral pulmonary artery stenosis.
basicII.A-037
On TEE, what is the aortic 'blind spot'?
→ The distal ascending aorta and proximal aortic arch — obscured by air in the trachea and mainstem bronchi lying between the esophagus and that aortic segment.
basicII.A-038
How do you distinguish a real intimal flap from an artifact in a dilated ascending aorta?
→ An intimal flap has independent oscillatory motion during the cardiac cycle. Reverberation/mirror-image artifacts move parallel to the aortic wall with no independent motion, and often have no rapid oscillatory motion.
basicII.A-039
What is 'Duroziez's sign' and what echo finding is it equivalent to?
→ Duroziez's = to-and-fro murmur over the femoral artery in severe AR. Echo analogue: holodiastolic reversal of flow in the proximal descending / abdominal aorta.
basicII.A-040
Where should the CW cursor be placed to obtain the highest AS velocity, and what maneuver may help?
→ Multiple windows: apical five-chamber, right parasternal (Pedoff nonimaging probe), and suprasternal. Use the highest velocity. Match systolic duration to the apical trace to avoid confusing MR/TR jets with AS.
basicII.A-041
What is valvulo-arterial impedance (Zva) and what does an elevated value indicate?
→ Zva = (mean gradient + systolic BP) / stroke volume index. It combines valvular and vascular load; a low value (< 3.5 mmHg·m²·mL⁻¹) is normal, high values suggest increased global LV afterload and worse prognosis in AS.
basicII.A-042
State the 2020 ACC/AHA valve staging system for aortic stenosis (Stages A–D).
→ Stage A: at risk (BAV or aortic sclerosis). Stage B: progressive (mild-moderate). Stage C1: asymptomatic severe with preserved LVEF. Stage C2: asymptomatic severe with LVEF < 50%. Stage D1: symptomatic high-gradient severe. Stage D2: symptomatic low-flow/low-gradient severe with reduced EF. Stage D3: symptomatic paradoxical low-flow/low-gradient severe with preserved EF.
basicII.A-043
State the 2020 ACC/AHA Class I indications for AVR in severe aortic stenosis.
→ 1) Symptomatic severe high-gradient AS (D1). 2) Asymptomatic severe AS with LVEF < 50% (C2). 3) Severe AS undergoing other cardiac surgery.
basicII.A-044
What thresholds define 'very severe' aortic stenosis?
→ Peak aortic velocity ≥ 5 m/s (or mean gradient ≥ 60 mmHg). Class IIa indication for AVR even if asymptomatic.
basicII.A-045
Give three imaging findings that trigger consideration of AVR in asymptomatic severe AS despite preserved EF.
→ 1) Abnormal exercise test (BP drop or symptoms). 2) Rapid progression (velocity increase ≥ 0.3 m/s per year). 3) Very severe AS (velocity ≥ 5 m/s). 4) Elevated BNP.
basicII.A-046
Which 2020 ACC/AHA aortic root threshold triggers surgery in BAV patients?
→ Aortic root or ascending aorta > 5.5 cm (any patient). > 5.0 cm if additional risk factors (family history of aortic dissection, growth > 5 mm/year, or coarctation). > 4.5 cm if undergoing AVR for AS/AR.
basicII.A-047
Estimating LV end-diastolic pressure from an AR jet — write the formula.
→ LVEDP = Diastolic BP − 4 × (end-diastolic AR jet velocity)². Normal LVEDP ~ 10–12 mmHg.
basicII.A-048
Describe the CW jet contour of chronic vs acute severe AR.
→ Chronic severe AR: relatively slow deceleration (PHT > 200 ms early on, shortens as chronicity progresses). Acute severe AR: steep deceleration slope (PHT < 200 ms) with rapid diastolic equalization of aortic and LV pressures.
basicII.A-049
Indications for AVR in chronic severe aortic regurgitation?
→ Class I: 1) Symptomatic severe AR. 2) Asymptomatic severe AR with LVEF ≤ 55%. 3) Severe AR undergoing other cardiac surgery. Class IIa: LVESD > 50 mm (or LVESDi > 25 mm/m²).
basicII.A-050
How does isometric handgrip affect an AR murmur?
→ Handgrip increases afterload (SVR) → increases regurgitant gradient → INTENSIFIES the AR murmur. Also intensifies MR. Reduces HCM and MVP murmurs.
basicII.A-051
How does amyl nitrite inhalation affect an AR vs an AS murmur?
→ Amyl nitrite reduces preload and afterload. AR murmur DECREASES (less regurgitant gradient). AS murmur INCREASES (higher gradient across the valve from tachycardia). HCM murmur INCREASES (unmasks obstruction).
basicII.A-052
State the ACC/AHA aortic root replacement thresholds for Marfan syndrome.
→ Aortic root or ascending aorta > 5.0 cm in Marfan. > 4.5 cm if additional risk factors (family history of dissection, growth > 3 mm/year). Loeys-Dietz uses even earlier thresholds.
basicII.A-053
How do you differentiate a suprasternal Doppler descending aortic flow pattern of severe AR from coarctation?
→ Severe AR: holodiastolic reversal in the descending aorta, but normal systolic ejection contour proximally. Coarctation: sustained antegrade DIASTOLIC flow (saw-tooth pattern) distal to the narrowing with elevated peak systolic velocity, and diastolic run-off is preserved (not reversed).
basicII.A-054
Which finding differentiates severe from moderate AR by CW deceleration slope?
→ Pressure half-time (PHT). PHT < 200 ms → severe AR. PHT > 500 ms → mild AR. Reflects rate of LV/aortic diastolic pressure equalization.
basicII.A-055
When is the aortic root measured for growth surveillance?
→ At the sinus of Valsalva in end-diastole (leading-edge to leading-edge, PLAX). Serial studies to detect growth > 3 mm/year (Marfan/genetic aortopathy) or > 5 mm/year (BAV).
