basicIII.A-001
What defines an ischemic response on stress echocardiography?
→ New or worsening regional wall-motion abnormalities in a coronary distribution. Reduced thickening (< 50%) or reduced excursion (< 5 mm) of the segment.
basicIII.A-002
What is a 'biphasic response' on dobutamine stress echo and what does it indicate?
→ Improvement in a dysfunctional segment at low dobutamine dose, then worsening at higher doses. Indicates VIABLE AND ISCHEMIC myocardium — the best target for revascularization.
basicIII.A-003
Target heart rate for a diagnostic stress echo?
→ ≥ 85% of age-predicted maximum HR (220 − age).
basicIII.A-004
Standard dobutamine infusion protocol for stress echo?
→ Incremental dose 5 → 10 → 20 → 30 → 40 μg/kg/min, each stage 3 min. Add atropine (0.25–1 mg) if target HR not reached.
basicIII.A-005
Stop criteria for dobutamine stress echo?
→ Achievement of target HR; new severe wall-motion abnormality; > 2 mm ST depression; hypertension > 220/120; symptomatic hypotension; symptomatic ventricular arrhythmia; intolerable symptoms.
basicIII.A-006
Typical timing of ventricular septal rupture after MI, and its location by infarct type?
→ 3–7 days post-MI. Anterior MI (LAD): apical VSD. Inferior MI (RCA): basal (posterior) VSD.
basicIII.A-007
Post-MI papillary muscle rupture — which one is more common and why?
→ Posteromedial > anterolateral. Posteromedial PM has a SINGLE blood supply (PDA territory); anterolateral has DUAL supply (LAD + LCx), so is more resistant to ischemia.
basicIII.A-008
Timing of post-MI free-wall rupture and typical outcome?
→ 3–7 days post-MI. Usually rapidly fatal from cardiac tamponade unless a contained rupture (pseudoaneurysm) develops.
basicIII.A-009
How do you distinguish a true LV aneurysm from a pseudoaneurysm on echo?
→ True: wide neck (neck-to-body ratio > 0.5), thinned continuous myocardium, low rupture risk. Pseudoaneurysm: narrow neck (< 0.5), wall composed of pericardium/thrombus, HIGH rupture risk — surgical urgency.
basicIII.A-010
After a large anterior MI, where does an LV thrombus typically form and how do you improve detection?
→ At the LV apex with underlying akinesis/dyskinesis. Contrast echo (LV opacification agent) significantly improves detection when the apex is poorly visualized.
basicIII.A-011
Recommended anticoagulation duration for a post-MI LV thrombus?
→ 3–6 months of therapeutic anticoagulation (warfarin traditionally; DOACs used off-label in many centers). Reassess with imaging.
basicIII.A-012
How does 'contractile reserve' on low-dose dobutamine identify viable myocardium?
→ Improvement of contraction in a dysfunctional segment at low-dose dobutamine indicates 'hibernating' viable myocardium. This predicts functional recovery after revascularization.
basicIII.A-013
Dressler's syndrome — timing and features?
→ Post-MI pericarditis at 2–8 weeks. Fever, pleuritic chest pain, pericarditis with pericardial effusion. Autoimmune reaction to myocardial antigens.
basicIII.A-014
In coronary segment mapping, which artery supplies the apex?
→ The apex has overlap — most commonly LAD supplies the anterior half of the apex; RCA (in a right-dominant system) or LCx (in a left-dominant) supplies the inferior apex. Apical segments are 'shared crown'.
basicIII.A-015
Which stress-echo modality is best when the primary question is myocardial viability?
→ Low-dose dobutamine stress echo. Watch for contractile reserve (improvement in resting dysfunctional segments) — most predictive of functional recovery after revascularization.
basicIII.A-016
When is contrast recommended during stress echocardiography?
→ When ≥ 2 of 6 basal or mid LV segments cannot be adequately visualized on baseline imaging.
