How to measure LVOT VTI
How to get it. Apical 5-chamber (or 3-chamber). Pulsed-wave Doppler, 3 to 5 mm sample in the LVOT about 0.5 cm below the aortic valve. Sweep 50 to 100 mm/s. Trace the modal (densest) edge of the envelope.
Quality checklist- Beam within 20° of flow
- Closing click visible, no opening click
- Narrow, hollow envelope
- 3 beats averaged (5 in AF)
Watch for. Too close to the valve overestimates (flow acceleration); too deep underestimates. A late-peaking, dagger-shaped signal means LVOT obstruction: switch to CW. Aortic regurgitation inflates VTI while effective flow is lower.
How to improve. Move the sample until only the closing click shows; tilt for alignment; lower gain and wall filter; average over the respiratory cycle.
Values. Normal 18 to 22 cm; below 15 cm low; below 10 cm very low.
Source: Lang RM, et al. J Am Soc Echocardiogr 2015; Quiñones MA, et al. J Am Soc Echocardiogr 2002.
How to measure LVOT diameter
How to get it. Parasternal long axis, zoomed on the LVOT. Mid-systole, inner edge to inner edge, perpendicular to the LVOT, within 0.5 to 1 cm of the aortic valve, at the same level where you will place the pulsed-wave sample.
Quality checklist- View zoomed on the LVOT
- Mid-systolic frame
- Inner edge to inner edge, perpendicular to flow
- Same level as the VTI sample
Watch for. Any error is squared: 1 mm off in a 2 cm LVOT changes stroke volume by about 10%. Calcification blurs the edges.
How to improve. Measure three times and use a reproducible value. Keep the same value for serial measurements, and trend VTI alone if the diameter is uncertain.
Values. Usually about 2 cm in adults; values outside 1.7 to 2.5 cm deserve a recheck.
Source: Lang RM, et al. J Am Soc Echocardiogr 2015.
How to measure LV systolic function (visual and biplane EF)
How to get it. Apical 4- and 2-chamber views. For biplane Simpson, trace the endocardium at end-diastole (largest frame, just after mitral closure) and end-systole (smallest frame), keeping papillary muscles inside the cavity. For a visual estimate, also look at PLAX and PSAX.
Quality checklist- The apex is thin and still (not foreshortened)
- The endocardium is visible in most segments
- Both apical views used, not one
- Heart rate regular, or several beats averaged
Watch for. Foreshortening shrinks volumes and distorts EF. EF depends on afterload: vasopressors can lower it, vasoplegia can flatter a weak LV. Tachycardia and AF make single beats unreliable.
How to improve. Slide one rib space down and more lateral to find the true apex; drop gain until the blood pool is black; use contrast if two or more segments are not seen; back it up with MAPSE.
Values. Normal 52 to 70%; mildly reduced 41 to 51%; moderately reduced 30 to 40%; severely reduced below 30%.
Source: Lang RM, et al. J Am Soc Echocardiogr 2015 (ASE chamber quantification).
How to measure MAPSE
How to get it. Apical 4-chamber. M-mode cursor through the lateral (and septal) mitral annulus, aligned with its motion. Measure from end-diastole to peak systolic excursion.
Quality checklist- Cursor parallel to annular motion
- Lateral and septal averaged if possible
- Measured on a clear annular line
Watch for. Angle-dependent; regional wall motion abnormalities and cardiac translation distort it.
How to improve. Rotate slightly until the annulus moves straight along the cursor.
Values. Below 8 mm suggests EF below 50%.
Source: Lang RM, et al. J Am Soc Echocardiogr 2015.
How to measure EPSS
How to get it. Parasternal long axis. M-mode through the tip of the anterior mitral leaflet; measure the smallest distance from the E-point to the septum.
Quality checklist- Cursor through the leaflet tip, not the body
- Perpendicular to the septum
Watch for. Unreliable with mitral stenosis, aortic regurgitation (jet hits the leaflet) or septal hypertrophy.
How to improve. Tilt so the cursor crosses the tip at its widest opening.
Values. Above 7 mm suggests reduced EF.
Source: Lang RM, et al. J Am Soc Echocardiogr 2015.
How to measure LVOT peak velocity (CW)
How to get it. Apical 5-chamber. Continuous-wave Doppler through the LVOT and aortic valve. Gradient = 4 × velocity².
Quality checklist- Late-peaking, dagger-shaped envelope
- Separated from the mitral regurgitation jet
Watch for. MR jets look similar but are longer and start earlier. Check for SAM in PLAX.
How to improve. Angle away from the mitral valve; confirm with PW mapping where the velocity steps up.
Values. 2.7 m/s or more is a gradient of about 30 mmHg (significant dynamic obstruction).
Source: Lang RM, et al. J Am Soc Echocardiogr 2015.
How to measure TAPSE
How to get it. RV-focused apical 4-chamber. M-mode cursor through the lateral tricuspid annulus, parallel to its motion. Measure peak excursion.
Quality checklist- RV-focused view
- Cursor parallel to annular motion
- Measured trough to peak
Watch for. Angle-dependent; reflects only longitudinal function. Falls after cardiac surgery even with good RV function; severe TR can overestimate it.
How to improve. Rotate to open the RV; align the cursor with the annulus path.
Values. Above 17 mm normal; below 10 mm severely reduced.
Source: ASE right heart guideline, 2025.
How to measure RV s′
How to get it. RV-focused apical 4-chamber. Tissue Doppler sample at the lateral tricuspid annulus; peak systolic velocity.
Quality checklist- Annulus aligned with the beam
- Peak velocity, not the edge of the spectral noise
Watch for. Angle-dependent; tachycardia narrows the signal.
How to improve. Lower gain and scale to sharpen the envelope.
Values. Above 9.5 cm/s normal.
Source: ASE right heart guideline, 2025.
How to measure RV FAC
How to get it. RV-focused apical 4-chamber. Trace the RV endocardium at end-diastole and end-systole, keeping trabeculations inside the cavity. FAC = (EDA − ESA) ÷ EDA.
Quality checklist- Whole RV free wall in view
- Trabeculations kept inside the trace
Watch for. Poor free-wall visibility is common in ventilated patients.
How to improve. Move lateral to the apex to bring the free wall into view.
Values. Above 35% normal; 22% or less severely reduced.
Source: ASE right heart guideline, 2025.
How to measure RV/LV size and septal shape
How to get it. Apical 4-chamber at end-diastole: compare basal RV and LV diameters. Parasternal short axis: look at septal shape in systole and diastole.
Quality checklist- Not foreshortened (true apex)
- End-diastolic frame
- Septum checked in PSAX
Watch for. Off-axis apical views make the RV look bigger or smaller. Systolic flattening means pressure overload; diastolic flattening means volume overload.
How to improve. Confirm in subcostal and PSAX views.
Values. RV/LV below 0.6 normal; 0.6 to 1 moderately dilated; 1 or more severely dilated.
Source: ASE right heart guideline, 2025.
How to measure IVC
How to get it. Subcostal long axis. Measure 1 to 2 cm from the RA junction, just below the hepatic vein, perpendicular to the IVC. Use M-mode or 2D through the respiratory cycle.
Quality checklist- It is the IVC, not the aorta (thin wall, no pulsation, enters the RA)
- 1 to 2 cm from the RA junction
- Respiratory mode recorded (spontaneous or ventilated)
Watch for. The IVC can slide out of plane (cylinder effect). High intra-abdominal pressure and ventilation change its size. It predicts fluid response poorly, especially in spontaneously breathing patients.
How to improve. Check in short axis; ask the patient to sniff only if appropriate.
Values. Small and collapsing below 1 cm; plethoric above 2.1 cm with less than 50% collapse.
Source: ASE right heart guideline, 2025; Via G, et al. Intensive Care Med 2016 (limits of IVC for fluid responsiveness).
How to measure Pericardial effusion and tamponade
How to get it. Subcostal and parasternal views. Look for effusion, RA collapse in systole, RV collapse in diastole, and a plethoric IVC.
Quality checklist- Effusion confirmed in two views
- Pericardial, not pleural (in PLAX, pericardial fluid lies in front of the descending aorta)
- Chamber collapse timed with the ECG or M-mode
Watch for. Loculated effusions after cardiac surgery can compress a single chamber. Tamponade is a clinical and echo diagnosis.
How to improve. Use M-mode through the RV free wall to time collapse.
Values. RA collapse lasting more than a third of the cycle, or RV diastolic collapse, suggests tamponade physiology.
Source: Klein AL, et al. J Am Soc Echocardiogr 2013 (pericardial disease).