SonographyAcademy

Curriculum · Clinical Ultrasound: Multisystem Diagnostic & Point-of-Care Sonography

Focused Cardiac Ultrasound (FoCUS) & Echocardiography

The five cardiac windows; qualitative LV function and EF (fractional shortening, Simpson's biplane, ASE ranges); pericardial effusion vs tamponade with IVC integration; and valvular regurgitation on color Doppler.

~45 min · level: advanced · POCUSAdult Echo draft — pending clinical review

Learning objectives

  • Acquire and recognize the PLAX, PSAX, apical 4-chamber, subcostal 4-chamber, and subxiphoid IVC views.
  • Estimate LV systolic function qualitatively and quantitatively (fractional shortening, Simpson's biplane EF; ASE normal ranges).
  • Distinguish a pericardial effusion from tamponade and integrate the IVC for right-atrial pressure.
  • Recognize a regurgitant valvular jet on color Doppler and connect it to the Doppler/hemodynamics course.

Focused cardiac ultrasound (FoCUS) answers binary, time-critical questions — gross LV function, pericardial effusion/tamponade, gross RV dilation, volume status — and is distinct from a comprehensive echocardiogram (full quantification by a credentialed sonographer/cardiologist). Both use the same windows.

Loading model…
Real anatomy mesh · Human-Organ3D · MIT · drag to rotate, scroll to zoom
Live 3D heart — rotate to relate the imaging planes to true cardiac anatomy. The long axis runs apex-to-base; the short axis is perpendicular to it.
ViewProbe position / indicatorKey structures

PLAX (parasternal long axis)

L sternal border, ~3–4th ICS, indicator → right shoulder

LV, LA, LVOT, aortic & mitral valves, RVOT, pericardium

PSAX (parasternal short axis)

Rotate 90° from PLAX

LV donut (assess wall motion), MV 'fish-mouth', papillary muscles

A4C (apical 4-chamber)

Apex/PMI, indicator → left, patient L-lateral decubitus

All four chambers, MV & TV, septum

Subcostal 4-chamber

Sub-xiphoid, probe nearly flat

Four chambers (good in arrest/PEA), pericardium

Subxiphoid IVC

Rotate to sagittal at xiphoid

IVC entering RA — size & collapsibility

The standard transthoracic windows.

Start with the parasternal views. The first clip is a real parasternal long axis (PLAX) — the RV outflow, LV, LA, and the aortic and mitral valves all line up along the heart's long axis. The second is a normal parasternal short axis (PSAX) — the LV in cross-section (the "donut"), the plane for regional wall-motion assessment.

2D B-mode (TTE)Parasternal long axis (PLAX) — mitral valve
Real clinical clip · Minardi G, Pino P, Manzara C, Pulignano G, Stefanini G, Viceconte G, Leonetti S, Madeo A, Gaudio C, Musumeci F · CC BY 2.0 · Preoperative scallop-by-scallop assessment of mitral prolapse — Cardiovasc Ultrasound (BMC), via Wikimedia Commons
Real parasternal long-axis (PLAX) TTE. Identify the LV and LA, the mitral and aortic valves, and the RV outflow anteriorly; the descending aorta sits behind the LA.
2D B-mode (TTE)Parasternal short axis — normal (apical level)
Real clinical clip · CardioNetworks: Vdbilt · CC BY-SA 3.0 · CardioNetworks ECHOpedia, via Wikimedia Commons
Normal parasternal short-axis (PSAX) at the papillary/apical level — the LV in cross-section. Sweep base-to-apex to inspect every wall for symmetric thickening.

The next cine is a real apical 4-chamber transthoracic echo. The chambers are labeled in the clip (RV, LV, RA, LA) and there is an anechoic stripe of pericardial effusion (PE). Freeze across the cardiac cycle, then measure the effusion depth with the caliper.

2D B-mode (TTE)Apical 4-chamber — pericardial effusion with RV/RA enlargement
Reveal findings
  • Anechoic (black) space in the pericardial sac = pericardial effusion; circumferential and large here.
  • Right ventricle and right atrium are dilated (this case is cor pulmonale), and the effusion compresses LV/LA.
  • Effusion size by end-diastolic depth: small < 1 cm, moderate 1–2 cm, large > 2 cm — but tamponade is a PHYSIOLOGIC diagnosis, not a size.

An anechoic stripe surrounds the heart within the pericardium and the chambers appear compressed. What is the single best label for the anechoic space?

Real clinical clip · Marš T, Mikolavčič H, Salobir B, Podbregar M · CC BY 2.0 · Echocardiography of isolated subacute left-heart tamponade in cor pulmonale — Cardiovasc Ultrasound (BMC), via Wikimedia Commons · caliper calibrated from the on-screen depth scale (approximate)
Apical 4-chamber TTE: enlarged right heart (RV/RA) with a pericardial effusion (PE) compressing the left chambers — a documented case of isolated subacute left-heart tamponade in cor pulmonale. Use the caliper to gauge the effusion's depth (approximate, from the depth scale).

Quantifying LV systolic function. A linear surrogate is fractional shortening from PLAX/PSAX M-mode:

FS=LVIDd−LVIDsLVIDd×100%\mathrm{FS} = \frac{\mathrm{LVID}_{d} - \mathrm{LVID}_{s}}{\mathrm{LVID}_{d}} \times 100\%
Fractional shortening from end-diastolic and end-systolic LV internal diameters (normal ≈ 25–45%). Geometry-dependent — unreliable with regional wall-motion abnormalities.

The volumetric standard is ejection fraction by the biplane method of disks (modified Simpson's), tracing the endocardium in A4C and A2C at end-diastole and end-systole:

EF=EDV−ESVEDV×100%(SV=EDV−ESV)\mathrm{EF} = \frac{\mathrm{EDV} - \mathrm{ESV}}{\mathrm{EDV}} \times 100\% \qquad (\text{SV} = \mathrm{EDV} - \mathrm{ESV})
EF = stroke volume / end-diastolic volume. Simpson's sums disk volumes from traced borders in two orthogonal apical views.
CategoryMenWomen

Normal

52–72%

54–74%

Mildly reduced

41–51%

41–53%

Moderately reduced

30–40%

30–40%

Severely reduced

< 30%

< 30%

ASE/EACVI LV ejection-fraction categories (biplane).

Valvular assessment begins with color-flow Doppler. The next clip pairs a 2-D image with color-flow Doppler (left/right panels) in a documented case of severe mitral regurgitation — a turbulent (mosaic) systolic jet into the left atrium. This is the Doppler course made visible: color encodes mean velocity/direction, and turbulence appears as variance (the mosaic).

2D + color DopplerColor-flow Doppler — severe mitral regurgitation (2D | color)
Reveal findings
  • Color Doppler maps flow toward/away from the probe (BART/RYBG maps vary); turbulent high-velocity flow shows aliasing and variance → the mosaic 'flame'.
  • A systolic jet from the LV across the mitral valve into the LA = mitral regurgitation; jet area and vena contracta help grade severity (CW Doppler and PISA quantify it).
  • Set the color box small and the Nyquist/scale appropriately — too-low scale over-calls turbulence (see the Doppler course on aliasing).

On color Doppler, a turbulent mosaic jet appears in the left atrium during systole, originating at the mitral valve. This indicates:

Real clinical clip · Minardi G, Pino P, Manzara C, Pulignano G, Stefanini G, Viceconte G, Leonetti S, Madeo A, Gaudio C, Musumeci F · CC BY 2.0 · Preoperative scallop-by-scallop assessment of mitral prolapse — Cardiovasc Ultrasound (BMC), via Wikimedia Commons
TTE with color-flow Doppler — severe mitral regurgitation. The mosaic (multicolor, high-variance) jet during systole projects from the mitral valve back into the left atrium.

Tamponade is a clinical–echocardiographic diagnosis: a pericardial effusion plus physiology — early RA systolic collapse (sensitive), RV diastolic collapse (specific), exaggerated respirophasic inflow variation, and a plethoric IVC. The clips below show the 2-D and the volume sides of the picture.

2D B-mode (TTE)Apical 4-chamber — pericardial effusion / tamponade

On this apical 4-chamber, an anechoic rim surrounds the heart and the right-sided chambers buckle inward in diastole. The single best interpretation is:

Real clinical clip · CardioNetworks: Secretariat · CC BY-SA 3.0 · CardioNetworks ECHOpedia (Tamponade case), via Wikimedia Commons
A second real apical 4-chamber with a circumferential pericardial effusion. Watch for diastolic right-heart chamber collapse and a 'swinging' heart — tamponade is physiology, not a size.
2D B-modeSubxiphoid IVC — plethoric, minimal respiratory variation (tamponade)
Reveal findings
  • A plethoric IVC (> 2.1 cm) that collapses < 50% with a sniff suggests elevated right-atrial pressure (~15 mmHg).
  • In the right clinical picture (effusion + hypotension), IVC plethora supports tamponade physiology.
  • Caveats: a plethoric IVC also occurs with RV failure, pulmonary hypertension, tension pneumothorax, and positive-pressure ventilation — integrate, don't isolate.

A dilated IVC with minimal respiratory variation, in a patient with a circumferential pericardial effusion and hypotension, most supports:

Real clinical clip · Ben Smith · CC BY 4.0 · UltrasoundCardiacTamponade — Wikimedia Commons
Subxiphoid long-axis IVC in cardiac tamponade — dilated (plethoric) and changing minimally with respiration, indicating elevated right-atrial pressure.
Worked example — fractional shortening

PLAX M-mode gives LVIDd = 5.4 cm and LVIDs = 4.3 cm. Compute fractional shortening and classify it.

Solution.

FS=(5.4−4.3)/5.4×100=1.1/5.4×100≈20%\mathrm{FS} = (5.4-4.3)/5.4 \times 100 = 1.1/5.4 \times 100 \approx 20\%. Normal FS is ~25–45%, so 20% is reduced, suggesting impaired LV systolic function — confirm with a volumetric EF (Simpson's), since FS samples only one plane and is invalid with regional wall-motion abnormalities.

Key takeaways

  • Tamponade is a physiologic diagnosis, not a size: a pericardial effusion plus early RA systolic collapse (sensitive), RV diastolic collapse (specific), and a plethoric IVC defines it.
  • Effusion size by end-diastolic depth is small < 1 cm, moderate 1-2 cm, and large > 2 cm, and on PLAX a pericardial effusion tracks anterior to the descending aorta while a pleural effusion tracks posterior to it.
  • Fractional shortening = (LVIDd - LVIDs)/LVIDd x 100% with normal about 25-45%, but it is geometry-dependent and unreliable with regional wall-motion abnormalities, so confirm with volumetric EF by Simpson's biplane.
  • ASE biplane EF is normal at 52-72% in men and 54-74% in women, with severely reduced below 30%, though FoCUS relies on a qualitative eyeball estimate watching endocardial excursion and wall thickening.
  • An IVC > 2.1 cm collapsing < 50% with a sniff indicates high right-atrial pressure (~15 mmHg) whereas <= 2.1 cm collapsing > 50% is normal (~3 mmHg), measured 1-2 cm from the cavo-atrial junction in a spontaneously breathing patient.

Check your understanding

Registry-style items with worked rationales.

1In the parasternal long-axis view, a fluid stripe that tracks ANTERIOR to the descending thoracic aorta is most consistent with:analysis

2Using the biplane method of disks, EDV = 120 mL and ESV = 75 mL. The ejection fraction is:application

3Which finding is the MOST SPECIFIC echocardiographic sign of cardiac tamponade?analysis

4A turbulent mosaic color-Doppler jet entering the left atrium during systole indicates:application

5An IVC measuring 2.4 cm that collapses ~10% with a sniff estimates a right-atrial pressure of about:application

Go deeper — trusted free resources

Hand-picked, verified links to authoritative open resources. Opens in a new tab.

ACEP SonoGuide
Echocardiography for Emergency Physicians (SonoGuide)

Practical walkthrough of the four standard FoCUS windows (PLAX, PSAX, apical 4-chamber, subcostal) plus pericardial effusion, IVC assessment, and qualitative ejection fraction estimation.

Open →
The POCUS Atlas
Echocardiography (TPA) — image atlas

Curated library of real bedside cardiac clips and stills illustrating normal anatomy, pericardial effusion, tamponade physiology, and reduced systolic function across each view.

Open →
Radiopaedia
Focus-assessed transthoracic echocardiography (FATE)

Reference article on the goal-directed FoCUS/FATE protocol, framing the targeted questions used to assess LV function, dilation, valvular abnormality, and pericardial fluid in unstable patients.

Open →
Radiopaedia
Echocardiography

Foundational overview of transthoracic echo windows, M-mode and Doppler basics, and assessment of effusion, IVC, and mitral regurgitation for trainees building on FoCUS skills.

Open →

References

  1. Moore CL, Copel JA. Point-of-care ultrasonography. N Engl J Med. 2011;364(8):749-757.
  2. American College of Emergency Physicians. Ultrasound Guidelines: Emergency, Point-of-care, and Clinical Ultrasound Guidelines in Medicine. 2016/2023.
  3. Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: ASE/EACVI update. J Am Soc Echocardiogr. 2015;28(1):1-39.
  4. Nagueh SF, Smiseth OA, Appleton CP, et al. Recommendations for the evaluation of LV diastolic function by echocardiography: ASE/EACVI update. J Am Soc Echocardiogr. 2016;29(4):277-314.