CCI RCS Adult Echo cheat sheet

Normal left ventricular wall thickness is 6-10 mm in diastole and the right ventricular free wall is normally under 5 mm; walls are measured at the chordal level, perpendicular to the long axis.

Coronary supply: the LAD perfuses the anterior wall, anteroseptum, and apex; the RCA perfuses the right ventricle, inferior wall, and inferior septum; the circumflex perfuses the lateral wall.

Cardiac cycle order: isovolumic contraction, rapid ejection, reduced ejection, isovolumic relaxation, rapid filling, diastasis, atrial systole.

The first heart sound is mitral and tricuspid closure; the second heart sound is aortic and pulmonic closure.

Normal stroke volume is 60-100 mL, cardiac output 4-8 L/min, and cardiac index 2.5-4.0 L/min/m2; cardiac output equals heart rate times stroke volume.

The right atrium receives the superior vena cava, inferior vena cava, and coronary sinus; the left atrium receives four pulmonary veins (right and left superior and inferior).

The normal aortic valve area is 3-4 cm2 and the valve has three cusps named right coronary, left coronary, and non-coronary.

Resting right atrial pressure is about 3-8 mmHg and normal right ventricular systolic pressure is roughly 15-30 mmHg; normal pericardial fluid volume is 15-50 mL.

Propagation speed in soft tissue is assumed to be 1540 m/s; wavelength in millimeters equals 1540 divided by the frequency in MHz.

Higher transmitted frequency produces a shorter wavelength, better axial resolution, greater attenuation, and less penetration.

Axial resolution equals spatial pulse length divided by two; it improves with fewer cycles per pulse and with higher frequency.

Lateral resolution is determined by beam width and improves with higher frequency, a larger aperture, and focusing at the depth of interest.

Attenuation in soft tissue is approximately 0.5 dB/cm/MHz; time-gain compensation corrects for depth-dependent loss of echo amplitude.

The Nyquist limit is pulse repetition frequency divided by two; aliasing occurs when the Doppler shift exceeds it and is corrected by raising PRF, lowering the baseline, shifting to a higher scale, or using continuous wave Doppler.

Doppler shift equals (2 x transmitted frequency x velocity x cosine of the angle) divided by 1540; a 60-degree angle underestimates velocity by 50 percent.

Frame rate equals pulse repetition frequency divided by lines per frame, so a narrower sector and shallower depth increase temporal resolution.

Mechanical index relates to cavitation and thermal index relates to heating; under ALARA keep MI at or below 1.9 and TI at or below 6.0 for general cardiac imaging.

Parasternal long axis displays the right ventricular outflow tract, aortic root, left ventricle, mitral valve, left atrium, and descending aorta; LV dimensions are measured at the chordal level.

Apical 4-chamber at roughly 0 degrees shows all four chambers and both atrioventricular valves; anterior angulation to about 10 degrees adds the LVOT and aortic valve in the 5-chamber view.

Apical 2-chamber shows the anterior and inferior walls; apical 3-chamber (long axis) shows the anteroseptum, inferolateral wall, LVOT, and aortic valve.

Subcostal imaging is the best window for the inferior vena cava, right atrium, and abdominal aorta and is the fallback when parasternal and apical windows are poor.

The suprasternal notch view images the aortic arch, its three branches, and the proximal descending thoracic aorta.

Chamber sizes and wall thickness are measured at end-diastole (QRS onset); LV volumes and ejection fraction use biplane Simpson method of disks at end-diastole and end-systole.

TEE midesophageal angles: 4-chamber about 0 degrees, 2-chamber about 90 degrees, long axis about 120 degrees, and transgastric mid short axis about 45 degrees.

For evaluating valvular regurgitant jets the color Doppler Nyquist limit is typically set at 50-70 cm/s.

Severe aortic stenosis: peak velocity at least 4 m/s, mean gradient at least 40 mmHg, valve area 1.0 cm2 or less, and dimensionless index below 0.25.

Severe mitral regurgitation: vena contracta at least 0.7 cm, effective regurgitant orifice at least 0.4 cm2, regurgitant volume at least 60 mL, and systolic flow reversal in pulmonary veins.

Severe mitral stenosis: valve area 1.0 cm2 or less, mean gradient at least 10 mmHg, pressure half-time at least 220 ms; rheumatic disease is the most common cause.

Hypertrophic cardiomyopathy: asymmetric septal hypertrophy, systolic anterior motion of the mitral leaflet, and a late-peaking dagger-shaped LVOT Doppler signal; obstruction is a gradient of 30 mmHg or more.

Cardiac amyloidosis: biventricular wall thickening, granular sparkling texture, apical-sparing longitudinal strain, and low ECG voltages relative to wall thickness.

Cardiac tamponade: moderate to large effusion, right atrial systolic collapse, right ventricular diastolic collapse, inferior vena cava plethora, and more than 25 percent respiratory variation in mitral inflow.

Constrictive pericarditis: pericardial thickening, septal bounce, annulus reversus with medial e-prime greater than lateral e-prime, and more than 25 percent respiratory variation in mitral inflow.

Bicuspid aortic valve is the most common congenital cardiac anomaly; ventricular septal defect is the most common defect diagnosed at birth; tetralogy of Fallot combines VSD, overriding aorta, RVOT obstruction, and right ventricular hypertrophy.

Modified Bernoulli equation: pressure gradient equals 4 times the square of peak velocity; RVSP equals 4 times the square of peak TR velocity plus right atrial pressure.

Continuity equation: aortic valve area equals (0.785 x LVOT diameter squared x LVOT VTI) divided by aortic valve VTI; LVOT diameter is measured inner edge to inner edge in mid-systole.

Stroke volume equals LVOT cross-sectional area times LVOT velocity-time integral; a normal LVOT VTI is approximately 18-22 cm.

PISA method: effective regurgitant orifice area equals (2 pi x radius squared x aliasing velocity) divided by peak regurgitant velocity; regurgitant volume equals EROA times the regurgitant jet VTI.

Mitral valve area by pressure half-time equals 220 divided by PHT in milliseconds; a PHT of 220 ms corresponds to an area of 1.0 cm2.

dP/dt from the mitral regurgitation jet equals 32 divided by the time in seconds between the 1 m/s and 3 m/s crossings.

Diastolic function: septal e-prime at least 7 cm/s, lateral e-prime at least 10 cm/s, E/e-prime below 8 normal, above 14 elevated filling pressure, and E/A ratio 1-1.5 with deceleration time 160-240 ms.

Keep the Doppler angle at or below 20 degrees; the detected shift falls with the cosine of the angle, so a 60-degree intercept records only half the true velocity.

ALARA means using the lowest mechanical and thermal indices and the shortest dwell time that still yield diagnostic information.

For general cardiac imaging keep mechanical index at or below 1.9 and thermal index at or below 6.0; stricter limits apply to ophthalmic and fetal exposures.

TEE requires fasting of roughly 6-8 hours, informed consent, sedation, and monitoring; contraindications include esophageal stricture, esophageal varices, and recent gastrointestinal surgery.

TEE probes contact mucous membranes and are semi-critical devices requiring high-level disinfection after every patient; external cardiac probes require low-level disinfection.

Ultrasound contrast agents are contraindicated in known hypersensitivity to perflutren and in patients with intracardiac shunts.

Standard precautions, hand hygiene, and cleaning of transducers and ECG leads reduce nosocomial transmission between patients.

Electrical safety includes inspecting cables and connectors, verifying proper grounding, and monitoring patient leakage current and transducer temperature.

Professional standards require patient privacy, informed consent for invasive or contrast procedures, and accurate documentation of measurements, findings, and limitations of the study.