basicII.C-001
Name the three mechanical valve types and describe flow through each.
→ 1) Ball-and-cage (Starr-Edwards) — flow around the cage, high peak velocities, central closing regurgitant jet. 2) Single tilting-disc — two orifices (major and minor). 3) Bileaflet tilting-disc (St Jude, On-X) — three orifices with three physiologic 'washing' regurgitant jets.
basicII.C-002
What is a Ross procedure and what long-term complication is characteristic?
→ Ross procedure = autograft replacement of the aortic valve using the patient's own pulmonary valve (a pulmonary homograft is placed in the pulmonary position). Late complication: autograft aortic regurgitation.
basicII.C-003
How deep from the annulus are balloon-expandable (Sapien) and self-expanding (CoreValve/Evolut) TAVR valves typically deployed?
→ Sapien: 2–4 mm below the annulus. CoreValve/Evolut: 3–6 mm below the annulus.
basicII.C-004
What is the recommended post-operative TTE follow-up schedule for bioprosthetic vs mechanical valves?
→ Both: initial TTE 2–4 weeks postoperatively to establish baseline. Bioprosthetic: annual TTE after 10 years. Mechanical: only if a change in symptoms or exam.
basicII.C-005
What is a normal peak velocity across an aortic prosthesis?
→ Less than 3 m/s. Velocities > 4 m/s or discordant DVI/AT suggest obstruction or PPM.
basicII.C-006
Define the Doppler velocity index (DVI) for aortic and mitral prostheses.
→ Aortic: V_LVOT / V_jet (or VTI_LVOT / VTI_jet). Mitral: V_jet / V_LVOT. Aortic normal DVI ≥ 0.35; < 0.25 suggests obstruction. Mitral VTI ratio > 2.2 abnormal.
basicII.C-007
Why is the DVI preferred over gradient alone for aortic prosthesis evaluation?
→ It is FLOW-independent and PROSTHESIS-SIZE independent — corrects for high output, PPM, small prostheses that would otherwise inflate gradient readings.
basicII.C-008
What acceleration time cutoff on the aortic prosthesis CW jet suggests pathologic obstruction?
→ AT > 100 ms suggests pathologic obstruction. Also: AT/ET > 0.4 indicates obstruction.
basicII.C-009
Contrast the CW jet contour of a normal vs pathologically obstructed aortic prosthesis.
→ Normal (or high-flow, PPM, pressure recovery): triangular/pointed early-peaking jet. Pathologic obstruction: rounded, mid-systolic (parabolic) peak.
basicII.C-010
Define iEOA and the thresholds for aortic patient-prosthesis mismatch.
→ iEOA = EOA / BSA. Aortic PPM present: iEOA < 0.85 cm²/m². Severe PPM: iEOA < 0.65 cm²/m². (Mitral PPM: < 1.2 moderate; < 0.9 severe.)
basicII.C-011
Why does patient-prosthesis mismatch develop and why is it not a valve malfunction?
→ PPM occurs when a normal, structurally intact prosthesis has an EOA too small for the patient's cardiac output demand (small valve in a large body). It reflects a size mismatch, not a mechanical valve problem.
basicII.C-012
What is the single most important Doppler finding for pathologic obstruction of a mitral prosthesis?
→ PHT ≥ 130 ms. This single value is the strongest indicator of pathologic mitral prosthesis obstruction.
basicII.C-013
E velocity ≥ 1.9 m/s and VTI ratio ≥ 2.2 on a mitral prosthesis with a NORMAL PHT (< 130 ms) — most likely diagnosis?
→ Significant mitral prosthesis REGURGITATION. Elevated flow raises E and VTI ratio, but PHT remains short because there is no true obstruction to LV filling.
basicII.C-014
Which equation should be used to calculate mitral prosthesis EOA — continuity or PHT?
→ Continuity equation: EOA = (CSA_LVOT × VTI_LVOT) / VTI_prosthesis. PHT-derived MVA overestimates prosthesis EOA and should NOT be used.
basicII.C-015
When is the continuity equation invalid for prosthesis EOA?
→ When significant AR or MR is present — LVOT-derived flow no longer equals valve flow.
basicII.C-016
Are microcavitations seen with mechanical valves pathologic?
→ No — microcavitations (microbubbles) are commonly seen with NORMALLY functioning bileaflet mechanical valves, especially on harmonic imaging.
basicII.C-017
Distinguish paravalvular from central prosthetic regurgitation.
→ Central: originates within the prosthesis. Small central 'washing' jets are normal for mechanical valves; larger central jets suggest bioprosthetic degeneration or endocarditis. Paravalvular: originates outside the sewing ring — ALWAYS pathologic.
basicII.C-018
Compare echocardiographic features of prosthetic valve thrombus vs pannus.
→ Thrombus: acute onset symptoms, larger, soft (similar echogenicity to myocardium), more common in mechanical mitral, mobile — may respond to anticoagulation. Pannus: gradual chronic symptoms, small, dense/echogenic, more common in aortic position, fixed — requires surgery.
basicII.C-019
Prosthetic aortic valve endocarditis with vegetation or root abscess most commonly causes what hemodynamic complication?
→ Aortic regurgitation. Less commonly AV block or acute MI from coronary compromise.
basicII.C-020
In which scenario is prosthetic-valve pressure recovery most clinically significant?
→ Small mechanical bileaflet aortic prostheses in patients with a small ascending aorta. Doppler overestimates gradient (and underestimates EOA) relative to catheter measurements.
basicII.C-021
What degree of prosthetic mitral valve 'rocking' motion suggests dehiscence?
→ Rocking motion > 15° across the annulus (best assessed by 3D echo). This is the gold-standard imaging finding for prosthetic MV dehiscence.
basicII.C-022
How do you handle a mechanical mitral prosthesis with a 'double spectral' Doppler profile?
→ Use the BRIGHTER (higher-velocity) portion of the profile for gradient calculation — this represents true transvalvular flow. The lower-velocity signal is central/orifice-related.
basicII.C-023
Age criteria that generally favor a BIOPROSTHESIS vs a MECHANICAL valve?
→ Bioprosthesis favored: age > 70 (low structural deterioration risk, avoid long-term anticoagulation). Mechanical favored: age < 50 (bioprosthesis has 15-y structural failure ~30% at age 40, 50% at age 20).
basicII.C-024
Which additional patient factors favor a bioprosthetic vs mechanical valve?
→ Bioprosthesis: high bleeding risk on anticoagulation, limited access to INR monitoring, non-compliance, small aortic root (allows future valve-in-valve TAVR). Mechanical: existing indication for anticoagulation (AF), high reoperation risk, compliant with INR.
basicII.C-025
What is the aortic regurgitation index (post-TAVR) and its cutoff for poor prognosis?
→ ARI = (Diastolic BP − LV end-diastolic pressure) / SBP × 100. ARI < 25 is associated with worse post-TAVR outcomes (measured invasively in the cath lab).
basicII.C-026
State two prosthetic valve findings that always warrant urgent evaluation.
→ Paravalvular regurgitation (always pathologic), and new hemolytic anemia with schistocytes/helmet cells (suggests high-shear paravalvular leak).
basicII.C-027
What features on TEE distinguish valvular from paravalvular regurgitation in a prosthetic MV?
→ Valvular: jet originates within the sewing ring, sometimes central (bileaflet washing jets are normal). Paravalvular: jet originates OUTSIDE the sewing ring. Paravalvular is ALWAYS pathologic; small paravalvular (5–20%) is common after TAVR.
basicII.C-028
State the normal peak velocity across a normally functioning bileaflet mechanical mitral prosthesis.
→ Peak E velocity < 1.9 m/s. Mean gradient 3–5 mmHg at HR 60–80. VTI ratio (prosthetic/LVOT) < 2.2. Peak velocities ≥ 1.9 m/s or gradient ≥ 6 mmHg with elevated VTI ratio suggests significant obstruction or high flow.
basicII.C-029
After TAVR, which imaging finding requires prompt investigation?
→ 1) New moderate or greater paravalvular AR. 2) New severe AS (leaflet thrombosis?). 3) Worsening EF or new wall-motion abnormality (coronary obstruction). 4) Pericardial effusion.
basicII.C-030
How is subclinical leaflet thrombosis (SLT) after TAVR detected?
→ Cardiac CT — hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RELM). Not always detectable on echo. Rising valve gradients on TTE prompt CT evaluation.
basicII.C-031
Which prosthesis is at highest risk of hemolysis and why?
→ Older mechanical valves (Björk-Shiley, older ball-and-cage) and any prosthesis with high-shear flow (small orifice + high gradient + paravalvular jet). Schistocytes and helmet cells on peripheral smear + elevated LDH signal hemolysis.
basicII.C-032
After bioprosthetic valve implantation, how do the transvalvular gradient and DVI change with age?
→ Over decades: leaflet degeneration (calcification, thickening) → progressively increased peak velocity and mean gradient, decreased DVI (< 0.25 for AV or > 2.5 VTI ratio for MV). Valve-in-valve TAVR often considered.
basicII.C-033
State the 2020 ACC/AHA anticoagulation recommendations for mechanical mitral vs mechanical aortic valves.
→ Mechanical mitral: warfarin INR target 3.0 (range 2.5–3.5) + low-dose aspirin. Mechanical aortic bileaflet (St Jude, On-X): INR target 2.5 (range 2.0–3.0) + low-dose aspirin. DOACs are NOT approved for mechanical valves.
basicII.C-034
Why is the acceleration time on the aortic prosthesis CW jet a marker of pathologic obstruction?
→ A pathologically obstructed prosthesis has resistance to ejection → the jet takes longer to reach peak velocity. AT > 100 ms suggests pathologic obstruction; AT ≤ 100 ms is normal (or high-flow / PPM / pathologic regurg).
basicII.C-035
How do bileaflet mechanical mitral valves normally appear on Doppler?
→ Three central regurgitant 'washing' jets from the hinges; peak E < 1.9 m/s; normal DVI. Physiologic microcavitations from bubble formation are visible on harmonic imaging — not pathologic.
basicII.C-036
What are two hallmarks of a normally functioning post-Ross procedure?
→ 1) Pulmonary autograft (native PV) now in aortic position — often develops progressive dilation and neo-AR over decades. 2) Pulmonary homograft in RV outflow — may develop RVOT PS or PR. Long-term surveillance is essential.
