Adult Echocardiography (AE) cheat sheet

The left ventricle is divided into 17 segments: six basal, six mid, four apical, and one apical cap; the apical segments and cap are assigned to the LAD territory.

Ejection fraction equals end-diastolic volume minus end-systolic volume divided by end-diastolic volume; a normal value is approximately 55-70%.

Cardiac output equals stroke volume times heart rate; stroke volume can be calculated as LVOT area multiplied by LVOT velocity-time integral.

LVOT area is calculated as pi times the square of half the LVOT diameter; the diameter is measured in mid-systole in the parasternal long-axis view.

Grade 1 diastolic dysfunction shows E/A below 0.8; grade 2 shows E/A 0.8-1.5 with elevated filling pressures; grade 3 shows E/A above 2 with restrictive filling.

Septal e' below 7 cm/s and lateral e' below 10 cm/s suggest impaired myocardial relaxation; E/e' above 14 suggests elevated left atrial pressure.

Right ventricular systolic pressure equals 4 times the square of peak tricuspid regurgitation velocity plus right atrial pressure estimated from IVC size and collapse.

Normal valve areas are approximately 3-4 cm² for the aortic valve, 4-6 cm² for the mitral valve, 7 cm² for the tricuspid valve, and 3 cm² for the pulmonary valve.

The normal pericardial space contains less than 50 mL of fluid; an echo-free space between the pericardium and myocardium indicates a pericardial effusion.

Frequency equals propagation velocity divided by wavelength; average soft-tissue propagation velocity is approximately 1540 m/s.

Attenuation in soft tissue is approximately 0.5 dB per centimeter per megahertz one-way; higher frequencies improve resolution but reduce penetration.

Axial resolution equals spatial pulse length divided by two; it improves with higher frequency and fewer cycles per pulse and is typically 0.5-1 mm.

Lateral resolution is worse than axial resolution and depends on beam width, transducer frequency, and depth; it improves with focusing.

The Nyquist limit equals pulse repetition frequency divided by two; Doppler shifts above this limit alias and wrap to the opposite direction.

Aliasing can be reduced by increasing pulse repetition frequency, lowering transducer frequency, or adjusting the color scale and baseline.

The Doppler equation is shift equals 2 times transducer frequency times velocity times cosine of the angle, divided by propagation velocity.

Pulsed-wave Doppler provides range resolution but aliases; continuous-wave Doppler records high velocities without aliasing but lacks range resolution.

Frame rate equals pulse repetition frequency divided by lines per frame; color Doppler, wider sectors, and greater depth reduce frame rate.

The parasternal long-axis view displays the right ventricle anteriorly, the left ventricle, aortic root, and left atrium; LVOT diameter is measured in mid-systole.

The apical four-chamber view places the LV apex at the top of the sector and is used for Simpson's biplane ejection fraction and mitral inflow Doppler.

Simpson's biplane method traces end-diastolic and end-systolic endocardial borders in apical four- and two-chamber views to calculate LV volumes.

M-mode uses a single cursor line with high temporal resolution; the cursor should be perpendicular to the structure, such as the aortic valve or mitral leaflets.

Pulsed-wave Doppler uses a sample volume for low-velocity flow with range resolution; it is used for LVOT, mitral inflow, and pulmonary vein velocities.

Continuous-wave Doppler is used for high-velocity jets such as aortic stenosis because it does not alias, but it cannot localize flow along the beam.

Color Doppler scale should be set above the expected velocity to avoid aliasing; variance maps display turbulent flow.

Tissue Doppler imaging samples myocardial motion at the septal and lateral mitral annulus to measure e' and a' velocities.

Doppler angle correction is applied to vascular flow but not to cardiac valve jets; valve velocities are most accurate when the beam is within 20 degrees of flow.

The continuity equation calculates aortic valve area as LVOT area times LVOT VTI divided by aortic valve VTI.

Severe aortic stenosis is defined by peak velocity at least 4 m/s, mean gradient at least 40 mmHg, or valve area below 1.0 cm².

The dimensionless index is LVOT VTI divided by aortic valve VTI; a value below 0.25 indicates severe aortic stenosis.

Mitral valve area by pressure half-time equals 220 divided by pressure half-time in milliseconds; a half-time above 220 ms suggests severe mitral stenosis.

Severe mitral regurgitation is suggested by a vena contracta of at least 0.7 cm or a PISA-derived effective regurgitant orifice area of at least 0.4 cm².

Aortic regurgitation pressure half-time below 200 ms suggests severe regurgitation; holodiastolic flow reversal in the descending aorta supports severity.

Tricuspid regurgitation velocity above 2.8 m/s suggests elevated right ventricular systolic pressure; a value above 3.4 m/s suggests severe pulmonary hypertension.

Normal prosthetic mean gradients are generally below 20 mmHg for aortic and below 5 mmHg for mitral valves; higher gradients suggest obstruction or patient-prosthesis mismatch.

Pulmonary stenosis with a peak velocity above 4 m/s or a mean gradient above 40 mmHg is considered severe.

Hypertrophic cardiomyopathy shows asymmetric septal hypertrophy of at least 15 mm, systolic anterior motion of the mitral leaflet, and dynamic LVOT obstruction with gradient at least 30 mmHg.

Cardiac amyloidosis shows thickened ventricular walls, a granular sparkling texture, apical sparing of longitudinal strain, and low ECG voltage relative to wall thickness.

Restrictive cardiomyopathy shows biatrial enlargement, normal or reduced LV cavity size, and grade 3 diastolic dysfunction with elevated filling pressures.

Cardiac tamponade shows a pericardial effusion with right atrial systolic collapse, right ventricular diastolic collapse, IVC plethora, and respiratory variation in inflow velocities.

Constrictive pericarditis shows pericardial thickening, septal bounce, annulus paradoxus, and medial e' greater than lateral e' on tissue Doppler.

Dilated cardiomyopathy shows LV dilation and reduced ejection fraction, often with functional mitral regurgitation; LV thrombus may require anticoagulation.

An atrial septal defect causes right heart volume overload, color flow across the interatrial septum, and increased pulmonary-to-systemic flow ratio.

A Stanford type A aortic dissection shows an intimal flap in the ascending aorta and is a surgical emergency; color Doppler may distinguish true and false lumens.