What is the recommended protocol for a cardiac doppler study?

Cardiac Doppler Protocol

A comprehensive cardiac Doppler study should follow the standardized protocol established by the American Society of Echocardiography and European Association of Cardiovascular Imaging, which includes systematic acquisition of mitral inflow velocities, tissue Doppler imaging of the mitral annulus, pulmonary vein flow assessment, and tricuspid regurgitation velocity measurement using specific technical parameters. 1

Core Doppler Measurements Required

Mitral Inflow Assessment

• Acquire from apical four-chamber view with color flow imaging to optimize alignment of pulsed-wave Doppler with blood flow 1
• Position the pulsed-wave Doppler sample volume (1-3 mm axial size) between mitral leaflet tips 1
• Use low wall filter setting (100-200 MHz) and low signal gain to avoid artifacts 1
• Record at sweep speed of 100 mm/sec for accurate measurements 1
• Measure peak E-wave velocity (early diastolic filling after ECG T wave) at the leading edge of spectral waveform 1
• Measure peak A-wave velocity (late diastolic filling after ECG P wave) at the leading edge 1
• Calculate E/A ratio by dividing E velocity by A velocity 1
• Measure deceleration time (DT) as the time interval from peak E-wave along the slope extrapolated to zero-velocity baseline 1

Tissue Doppler Imaging of Mitral Annulus

• Acquire from apical four-chamber view with pulsed-wave Doppler sample volume (5-10 mm axial size) 1
• Measure at both septal and lateral basal regions to compute average e′ velocity 1, 2
• Use ultrasound system presets for wall filter and lowest signal gain 1
• Measure peak e′ velocity in early diastole at the leading edge of spectral waveform 1
• Calculate E/e′ ratio by dividing mitral E velocity by mitral annular e′ velocity 1, 2
• Abnormal values: septal e′ < 7 cm/sec, lateral e′ < 10 cm/sec 2

Pulmonary Vein Flow Assessment

• Position sample volume 1-2 cm into right or left upper pulmonary vein using color flow imaging guidance 1
• Use pulsed-wave Doppler sample volume (1-3 mm axial size) 1
• Apply low wall filter setting (100-200 MHz) and low signal gain 1
• Measure peak S wave velocity (systolic forward flow) at leading edge 1
• Measure peak D wave velocity (diastolic forward flow) at leading edge 1
• Measure atrial reversal (AR) wave duration from onset to end at zero baseline 1
• Calculate Ar-A duration difference (pulmonary vein AR duration minus mitral A duration) 1

Tricuspid Regurgitation Velocity

• Use continuous-wave Doppler from parasternal and apical four-chamber views with color flow imaging 1
• Align Doppler beam parallel to TR jet using multiple transducer positions to record highest velocity 3
• Adjust gain and contrast to display complete spectral envelope without signal spikes 1
• Measure peak modal velocity during systole at leading edge of spectral waveform 1
• TR velocity > 2.8 m/sec suggests elevated left atrial pressure 1, 2

Left Atrial Volume Measurement

• Acquire apical four-chamber and two-chamber views with freeze frames 1-2 frames before mitral valve opening 1
• Measure LA volume in dedicated views where LA length and transverse diameters are maximized 1
• Use method of disks or area-length method and correct for body surface area 1
• Do not include LA appendage or pulmonary veins in tracings 1
• LA maximum volume index > 34 mL/m² indicates chronically elevated filling pressures 2

Additional Hemodynamic Parameters

Isovolumic Relaxation Time (IVRT)

• Acquire from apical long-axis or five-chamber view using continuous-wave Doppler 1
• Place sample volume in LV outflow tract to simultaneously display end of aortic ejection and onset of mitral inflow 1
• Measure time between aortic valve closure and mitral valve opening 1
• Use sweep speed of 100 mm/sec 1

Color M-Mode Propagation Velocity (Vp)

• Acquire from apical four-chamber view with color flow imaging for M-mode cursor position 1
• Shift color baseline toward mitral valve inflow to lower velocity scale 1
• Measure slope of inflow from MV plane into LV chamber during early diastole at 4-cm distance 1

Special Maneuvers

Valsalva Maneuver

• Record mitral inflow continuously for 10 seconds during straining phase using pulsed-wave Doppler 1
• Decrease in E/A ratio ≥50% (not caused by E and A fusion) is highly specific for increased LV filling pressures 1
• This maneuver distinguishes normal from pseudonormal filling patterns 1

Technical Optimization Principles

• Optimal spectral waveforms should not display spikes or feathering 1
• Use color flow imaging for optimal alignment of pulsed-wave Doppler with blood flow direction 1
• Measurements should be taken over 1-3 cycles in sinus rhythm 1
• In atrial fibrillation, average 5 cycles during physiologic heart rate (65-85 bpm) when possible 1
• Match respective cycle lengths to within 10% for calculations requiring measurements from different cardiac cycles 1
• Perform recordings in quiet respiration or mid-expiratory apnea 1

Common Pitfalls to Avoid

• Avoid high wall filter settings which cause signal loss and feathering 1
• Avoid excessive gain which creates artifacts and obscures true spectral envelope 1
• Do not measure from off-axis views where Doppler alignment is suboptimal 1
• Ensure sample volume is properly positioned - mitral inflow at leaflet tips, tissue Doppler at annulus 1
• In atrial fibrillation, use matched RR intervals when comparing E and e′ velocities 1
• Recognize that E/e′ ratio is rarely >14 in normal individuals regardless of age 1