260.1 🎓 醫孞生版

260.1.0.1 📌 䞀頁重點

260.1.0.1.1 Modalities
  • TTE (Transthoracic Echocardiogram): standard, non-invasive
  • TEE (Transesophageal Echocardiogram): better posterior structures + atria + endocarditis vegetations + valves
  • Stress echo: exercise or pharmacologic (dobutamine, vasodilator); ischemia
  • 3D echo: chamber quantification, valve morphology
  • Strain imaging (speckle tracking): early LV dysfunction detection (GLS — global longitudinal strain)
  • Contrast echo: improves endocardial border definition (microbubbles)
  • POCUS (Point-of-Care Ultrasound): bedside; ICU + ED
260.1.0.1.2 Indications
260.1.0.1.2.1 Heart Failure
  • Initial assessment of LVEF, chamber sizes
  • HFpEF vs HFrEF differentiation
  • Wall motion abnormalities
  • Diastolic function
  • Pulmonary artery pressure estimation (TR jet)
260.1.0.1.2.2 Valvular Disease
  • Severity assessment (AS, MR, AR, MS, TR)
  • Etiology (degenerative, rheumatic, congenital)
  • Mechanism of regurgitation
  • Surgical / TAVR planning
260.1.0.1.2.3 Coronary Artery Disease
  • Wall motion abnormalities at rest + with stress
  • LV function post-MI
  • Complications (LV aneurysm, mural thrombus, septal rupture, papillary muscle rupture)
260.1.0.1.2.4 Endocarditis
  • Vegetations (TEE more sensitive)
  • Abscess
  • Valvular regurgitation new
  • Prosthetic valve assessment
260.1.0.1.2.5 Pericardial Disease
  • Effusion (size, hemodynamic significance)
  • Tamponade signs
  • Constrictive pericarditis (Doppler patterns)
260.1.0.1.2.6 Cardiomyopathy
  • DCM, HCM, RCM, ARVC, takotsubo
  • Wall thickness, chamber size
  • Functional assessment
260.1.0.1.2.7 Congenital Heart Disease
  • ASD, VSD, PDA, tetralogy, others
  • Adult congenital cardiology
260.1.0.1.2.8 Aortic Disease
  • Aortic root + ascending dilation
  • Coarctation (TTE limited; better with MRI/CT)
  • Dissection (TEE often more diagnostic than TTE)
260.1.0.1.2.9 Pulmonary Hypertension
  • PA pressure estimation
  • RV size + function
  • TR jet for PASP
260.1.0.1.2.10 Stroke / Embolic Source
  • LV thrombus
  • LA thrombus (TEE for left atrial appendage)
  • ASD / PFO with bubble study
  • Vegetations
  • Aortic atheroma
260.1.0.1.3 Standard Views (TTE)
260.1.0.1.3.1 Parasternal Long Axis (PLAX)
  • LV + LA + aortic root + ascending aorta
  • Mitral valve + aortic valve
  • LV size + function
  • M-mode: traditional measurements
260.1.0.1.3.2 Parasternal Short Axis (PSAX)
  • LV from base to apex (sweep through)
  • Aortic valve (3 cusps visible)
  • Mitral valve (fish-mouth)
  • Papillary muscle level
  • Apex
260.1.0.1.3.3 Apical 4-Chamber (A4C)
  • All 4 chambers
  • LV function (Simpson’s method for EF)
  • Mitral + tricuspid valves
  • Septal + lateral walls
  • Doppler of mitral + tricuspid
260.1.0.1.3.4 Apical 5-Chamber
  • Apical 4C + aortic outflow
  • LVOT velocity (AS gradient)
260.1.0.1.3.5 Apical 2-Chamber
  • LV from apex (anterior + inferior walls)
  • LV function (biplane Simpson’s)
260.1.0.1.3.6 Subcostal
  • All 4 chambers (alternative angle)
  • IVC (inspiratory collapse — volume status)
  • Pericardium
260.1.0.1.3.7 Suprasternal
  • Aortic arch
  • Coarctation
  • Descending aorta
260.1.0.1.4 Doppler
260.1.0.1.4.1 Continuous Wave Doppler
  • High velocity (jets, regurgitation, stenosis)
  • AS peak gradient (Bernoulli equation: 4V²)
  • TR jet → RV systolic pressure → PASP estimation
260.1.0.1.4.2 Pulsed Wave Doppler
  • Low velocity, location-specific
  • LV inflow (mitral E + A waves) — diastolic function
  • Pulmonary vein flow
  • LVOT velocity (cardiac output calculation)
260.1.0.1.4.3 Color Doppler
  • Visualize flow direction + turbulence
  • Identify regurgitation + shunt jets
  • Pulmonary HTN (RV outflow turbulence)
260.1.0.1.4.4 Tissue Doppler
  • Myocardial velocity
  • Diastolic function (e’ velocity)
  • E/e’ ratio (filling pressure estimate)
260.1.0.1.5 LV Function Assessment
260.1.0.1.5.1 Ejection Fraction (EF)
  • Visual estimation (gestalt)
  • Simpson’s method (biplane): most accurate
  • 3D echo: more accurate than 2D
  • Categories:
    • HFrEF: ≀ 40%
    • HFmrEF: 41-49%
    • HFpEF: ≥ 50%
260.1.0.1.5.2 Global Longitudinal Strain (GLS)
  • Strain imaging (speckle tracking) — measures myocardial deformation
  • Normal GLS: -18% to -22% (more negative)
  • Early LV dysfunction: GLS less negative (-15%)
  • Subclinical detection in cancer chemotherapy + cardiotoxicity + early HFpEF
  • Increasingly used in cardio-oncology + heart failure
260.1.0.1.5.3 Wall Motion Abnormalities
  • Hypokinetic: reduced wall motion
  • Akinetic: no wall motion
  • Dyskinetic: paradoxical (outward) motion
  • Hyperkinetic: increased (compensatory)
  • Coronary territory correlation
  • Stress echo for ischemia (new wall motion abnormality with stress)
260.1.0.1.6 Diastolic Function
260.1.0.1.6.1 Parameters
  • Mitral inflow: E wave (early) + A wave (atrial contraction)
  • E/A ratio: normal 1-2; reversed (< 1) = impaired relaxation
  • Pseudonormal pattern (intermediate)
  • Restrictive (E >> A, short decel time) — severe HFpEF
  • Tissue Doppler e’: lateral / septal mitral annulus
  • E/e’ ratio: estimates LV filling pressure
    • E/e’ < 8: normal
    • E/e’ > 14: elevated filling pressure
    • 8-14: intermediate
260.1.0.1.6.2 Diastolic Dysfunction Grades
  • Grade 1: impaired relaxation (E/A < 1, normal filling pressure)
  • Grade 2: pseudonormal (E/A 1-2 but elevated E/e’)
  • Grade 3: restrictive (E/A > 2, E/e’ > 14)
260.1.0.1.7 Valvular Disease Assessment
260.1.0.1.7.1 Aortic Stenosis (AS)
  • Severe AS criteria:
    • Peak velocity > 4 m/s
    • Mean gradient > 40 mmHg
    • Valve area < 1 cm² (or < 0.6 cm²/m² indexed)
  • Symptom triad: dyspnea + angina + syncope → consider valve replacement
  • TAVR vs SAVR consideration
260.1.0.1.7.2 Mitral Regurgitation (MR)
  • Primary (organic; degenerative MVP, rheumatic, endocarditis, ruptured chordae)
  • Secondary (functional; HFrEF with mitral annular dilation)
  • Severity: vena contracta, PISA, effective regurgitant orifice area (EROA), regurgitant volume
260.1.0.1.7.3 Aortic Regurgitation (AR)
  • Severity: jet width, vena contracta, holodiastolic flow reversal in descending aorta
260.1.0.1.7.4 Mitral Stenosis (MS)
  • Mostly rheumatic worldwide
  • Mean gradient + valve area assessment
  • Pressure half-time method for valve area
  • Severe MS: valve area < 1 cm²
260.1.0.1.7.5 Tricuspid Regurgitation (TR)
  • Often functional from RV dilation + PHTN
  • Severe TR: severe RV dilation, dilated annulus, vena contracta > 7 mm

260.1.0.2 1⃣ TEE Specific Indications

260.1.0.2.1 TTE Limitations → TEE Considered
  • Endocarditis: vegetations (TEE > TTE; especially prosthetic valve, posterior valves, paravalvular abscess)
  • Atrial / mitral pathology: LAA thrombus (especially pre-cardioversion AF), mitral disease (rheumatic, MVP, posterior leaflet)
  • Aortic dissection: TEE highly sensitive (especially ascending)
  • Embolic source: LAA thrombus, PFO/ASD, aortic atheroma
  • Intraoperative TEE: cardiac surgery + structural intervention (TAVR, MitraClip, MitraValve, etc.)
  • Obese / COPD / mechanical ventilation: poor TTE windows
260.1.0.2.2 TEE Procedure
  • Conscious sedation (often midazolam + fentanyl)
  • Topical anesthesia
  • Probe inserted through esophagus → mid-esophageal + transgastric views
  • 30-60 min typically
260.1.0.2.3 TEE Risks
  • Esophageal injury (rare)
  • Esophageal perforation (very rare)
  • Aspiration
  • Sedation-related (respiratory depression)
  • Bacteremia risk (transient, low; antibiotic prophylaxis no longer routine per IDSA 2024)
260.1.0.2.4 TEE Views
  • Mid-esophageal: 4-chamber, 2-chamber, long axis
  • Transgastric: short axis (LV, valves)
  • Aortic views: ascending, descending

260.1.0.3 2⃣ Stress Echo

260.1.0.3.1 Types
260.1.0.3.1.1 Exercise Echo
  • Treadmill or bicycle (supine or upright)
  • Most common
  • ECG + echo at rest + peak + recovery
260.1.0.3.1.2 Pharmacologic Echo
  • Dobutamine: progressive infusion → inotropic stress (max HR + contractility)
  • Vasodilator (dipyridamole, adenosine, regadenoson): induces coronary steal (less used)
260.1.0.3.2 Indications
  • Ischemia evaluation in patients unable to exercise (joint disease, etc.)
  • Pre-operative cardiac risk assessment
  • Viability assessment (low-dose dobutamine — biphasic response)
  • Valve assessment under stress
260.1.0.3.3 Findings
  • Inducible wall motion abnormality → ischemia
  • Worsening EF at peak stress → ischemia
  • Increased gradient at peak (AS) → worsening AS
260.1.0.3.4 Sensitivity / Specificity
  • ~ 85% / 85% for CAD
  • Comparable to nuclear stress
  • Operator-dependent

260.1.0.4 3⃣ POCUS (Point-of-Care Ultrasound)

260.1.0.4.1 Indications
  • ED + ICU + clinic rapid assessment
  • Cardiac arrest: PE, tamponade, severe LV dysfunction
  • Shock: volume status, RV / LV function
  • Acute dyspnea: HF vs PE vs pneumothorax vs effusion
  • Trauma: pericardial effusion (FAST exam)
  • Volume status: IVC, B-lines (lung POCUS)
260.1.0.4.2 Skills
  • Basic 4-chamber + parasternal views
  • IVC assessment
  • Lung POCUS (B-lines, sliding sign)
  • FAST exam (focused abdominal)
260.1.0.4.3 Training + Competence
  • POCUS becoming standard in EM, IM, ICU, primary care
  • Multi-specialty training programs
  • Increasing literature on impact

260.1.0.5 4⃣ Contrast Echo

260.1.0.5.1 Indications
  • Suboptimal endocardial border definition
  • LV thrombus assessment
  • Right-to-left shunt (PFO with bubble study)
260.1.0.5.2 Contrast Types
260.1.0.5.2.1 Microbubbles (Definity, Optison, Lumason)
  • Improves endocardial border
  • Safe (perflutren-based)
  • Rare allergic reactions
260.1.0.5.2.2 Agitated Saline (“Bubble Study”)
  • For right-to-left shunt detection (PFO, intra-pulmonary)
  • During Valsalva for PFO

260.1.0.6 5⃣ Strain Imaging + Advanced Techniques

260.1.0.6.1 Global Longitudinal Strain (GLS)
  • Measures myocardial fiber shortening longitudinally
  • Speckle tracking technology
  • More sensitive than EF for early dysfunction
  • Normal: -18% to -22% (more negative = better)
  • Cardio-oncology: detects chemotherapy cardiotoxicity early
  • HFpEF: GLS reduced despite normal EF
260.1.0.6.2 3D Echo
  • More accurate chamber volumes + EF
  • Valve morphology
  • Real-time / intra-procedural guidance (TAVR, MitraClip)
260.1.0.6.3 Cardiac Magnetic Resonance Imaging (CMR — see Ch 261)
  • Gold standard for myocardial structure + tissue characterization
  • Echo complement for specific assessment
260.1.0.6.4 AI in Echo
  • Automated EF estimation
  • LV strain analysis
  • Valvular assessment
  • Image acquisition guidance
  • FDA-approved AI tools (2023+)

260.1.0.7 6⃣ Specific Patterns + Pearls

260.1.0.7.1 LV Hypertrophy Patterns
  • Concentric (HTN, AS): thickened walls, normal chamber
  • Eccentric (volume overload — AR, MR): thickened walls + dilated chamber
  • HCM (asymmetric septal hypertrophy): septum disproportionate to free wall (ratio > 1.3)
  • Athlete’s heart: physiologic hypertrophy (sometimes difficult to differentiate from HCM)
260.1.0.7.2 RV Dysfunction Patterns
  • RV dilation
  • RV hypokinesis
  • RV/LV ratio > 1 in apical 4-chamber
  • McConnell’s sign (RV free wall akinesis + apical sparing) — acute PE
  • Septal flattening (D-shaped LV) — pressure / volume overload of RV
260.1.0.7.3 Pericardial Effusion
  • Anechoic space surrounding heart
  • Small / moderate / large / massive
  • Tamponade signs:
    • RA collapse during diastole
    • RV collapse during early diastole
    • IVC plethora (no inspiratory collapse)
    • Doppler respiratory variation in MV inflow (> 25%) + TV inflow (> 40%)
260.1.0.7.4 LV Thrombus
  • Often apical (post-MI)
  • Apical akinesis + thrombus
  • Contrast echo improves detection
260.1.0.7.5 Bicuspid Aortic Valve
  • 2-cusp configuration
  • Often associated with aortic dilation
  • AS / AR more common
  • Family screening for relatives
260.1.0.7.6 Hypertrophic Cardiomyopathy (HCM)
  • Asymmetric septal hypertrophy (septum / free wall > 1.3)
  • LVOT obstruction (SAM — systolic anterior motion of mitral valve)
  • Dynamic obstruction with Valsalva
  • Mitral regurgitation (often)
260.1.0.7.7 Cardiac Amyloidosis
  • Concentric LVH (often disproportionate to clinical HTN)
  • “Sparkling” echo texture
  • Diastolic dysfunction
  • Apical sparing on strain imaging (pathognomonic — cherry-on-top pattern)
  • Right ventricular involvement
  • Subtype: AL vs ATTR