A 78-year-old patient with severe calcific AS is considered high-risk for surgery (STS score 9%). The preferred treatment is:
Answer: C
Explanation: TAVR is indicated in severe symptomatic AS patients who are high- or prohibitive-risk for SAVR. Balloon valvuloplasty provides only temporary relief and is not definitive therapy.
Teaching Points: - TAVR is now also preferred in many intermediate risk patients.
- Valve durability remains a concern in younger patients.
In severe aortic stenosis, which of the following is the earliest symptom indicating need for intervention?
Answer: C
Explanation: Dyspnea on exertion from progressive LV failure is often the earliest presenting symptom in severe AS. Syncope and angina typically appear later, and sudden cardiac death is rare without preceding symptoms.
Teaching Points: - Symptomatic severe AS requires valve replacement.
- Survival after onset of symptoms is poor (2–3 years).
In chronic severe primary mitral regurgitation, the indication for surgery in asymptomatic patients is:
Answer: D
Explanation: In severe MR, surgery should be performed before LV function falls. Surgery is recommended when LVEF ? 60% or LVESD ? 40 mm, even if the patient is asymptomatic.
Teaching Points: - MR causes volume overload ? LV dilation occurs before drop in EF.
- Threshold is LVEF 60%, not 50% like in most valve diseases.
A 35-year-old woman with moderate MS plans pregnancy. She is currently asymptomatic. PASP is 55 mmHg. The next step is:
Answer: C
Explanation: Pregnancy increases blood volume and cardiac output, which worsens MS. In asymptomatic severe MS or moderate MS with PASP > 50 mmHg, PBMV is recommended before pregnancy.
Teaching Points: - Pre
- pregnancy intervention reduces maternal and fetal complications.
- MR tolerance is better in pregnancy than MS.
All are contraindications to balloon mitral valvotomy except:
Answer: D
Explanation: PBMV requires commissural fusion to be effective. It is contraindicated in the presence of LA thrombus, moderate or severe MR, or severe calcification.
Teaching Points: - Commissural fusion is required for the balloon to split the commissures.
- PBMV is a procedure targeting commissures, not leaflets.
The treatment of choice for symptomatic severe rheumatic mitral stenosis with Wilkins score of 6, no LA thrombus, and mild MR is:
Answer: B
Explanation: Percutaneous balloon mitral valvotomy (PBMV) is preferred in severe MS when valve morphology is favorable (Wilkins score ? 8), MR ? mild, and no LA thrombus. It offers good hemodynamic improvement with low perioperative risk.
Teaching Points: - PBMV is first line if valve is pliable and commissural fusion is present.
- Open commissurotomy/replacement is used when anatomy is not suitable for PBMV.
In rheumatic mitral stenosis, the earliest pathological change is:
Answer: C
Explanation: Rheumatic inflammation first causes fibrinous leaflet edge thickening and scarring. With progression, commissural fusion and chordal thickening/shortening develop. Calcification occurs late.
Teaching Points: - Early leaflet involvement precedes commissural fusion.
- Chordal rupture is atypical in MS (more seen in MR etiologies).
The most common cause of mitral stenosis worldwide is:
Answer: B
Explanation: Rheumatic heart disease remains the primary global cause of mitral stenosis, especially in Asia. Rheumatic inflammation leads to commissural fusion, leaflet thickening, and chordal shortening, producing the classic "fish-mouth" stenosis.
Teaching Points: - Rheumatic MS almost always involves commissural fusion.
- Calcific MS is more common in elderly populations of Western countries.
Which of the following is the most reliable echocardiographic predictor of recurrent MR after mitral valve repair in ischemic MR?
Answer: C
Explanation: Posterior leaflet tethering height (also measured as tenting height) reflects the severity of papillary muscle displacement and predicts poor leaflet coaptation even after annuloplasty. Tenting > 10 mm indicates a high recurrence risk of MR despite repair.
Teaching Points: - Tenting height > 10 mm and tethering angle > 45° predict failure of repair ? consider replacement.
- In ischemic MR, subvalvular geometry is more important than annular size alone.
In ischemic functional mitral regurgitation (FMR), the primary mechanism leading to regurgitation is:
Answer: B
Explanation: Functional MR occurs without intrinsic leaflet pathology. In ischemic LV remodeling, the papillary muscles are displaced laterally and apically. This causes leaflet tethering and failure of leaflet coaptation. Annular dilatation further worsens MR. Leaflets remain anatomically normal.
Papillary muscle rupture (Option D) causes acute, flail MR, not chronic FMR.
Structural degeneration (Option A) is seen in degenerative MR, not ischemic MR.
Teaching Points: - Ischemic MR = ventricular disease, not valvular disease.
- Repair strategies focus on restrictive annuloplasty and subvalvular apparatus correction (tethering correction).
- Severe tethering predicts repair failure ? consider chordal cutting or replacement.
A 62-year-old man with severe symptomatic aortic stenosis is scheduled for valve replacement. Echocardiography shows heavy concentric LV hypertrophy and a small LV cavity. During weaning from cardiopulmonary bypass, he develops hypotension with low cardiac output despite adequate preload. Which of the following is the most likely cause?
Answer: A
Explanation: Explanation:
In patients with long-standing severe aortic stenosis, the LV becomes hypertrophied and the cavity becomes small. After valve replacement, the sudden drop in afterload can cause systolic anterior motion of the mitral valve leading to dynamic LVOT obstruction, similar to the physiology of hypertrophic obstructive cardiomyopathy. This leads to hypotension and low cardiac output during coming off bypass. Management involves reducing inotropes, giving volume, and using beta-blockade if needed.
Teaching Points: Severe AS patients can mimic HOCM physiology after AVR.
Avoid high inotropes; they worsen the obstruction.
Treat with volume expansion and beta-blockers.
Dynamic LVOT obstruction is a recognized cause of post-operative low cardiac output after AVR.