Diastolic Flow Reversal Aortic Regurgitation

Regurgitant Fraction (RF)

SVAv-SV

mv sv av

SVAV = 0.785 x {LVOT} x VTIlvdt im pw, SVmv = 0.785 x (Dmv)2 x YWntbypin

Regurgitation Severity (by RV) mL/beat

Moderate ... 30 -59 mL/beat Severe > 60 mL/beat

Regurgitation Severity (by RF} %

Fig. 15. Aortic regurgitant volume and fraction.

diastole and is proportional to regurgitant severity. Grading of aortic regurgitation severity using the regurgitant orifice area is as follows: mild, less than 0.10 cm2; moderate, between 0.10 and 0.30 cm2; and severe, more than 0.30 cm2.

Calculation of the regurgitant volume, fraction, and orifice area is dependent on careful measurement of several variables. Errors in any one of these variables will lead to further errors in the calculations. Experienced laboratories should be able to perform these measurements and calculations accurately with careful attention to detail.

Aortic regurgitation can lead to diastolic flow reversal in the aorta (Fig. 17). With milder degrees of regurgitation, there is brief reversal of flow early in diastole. As the degree of regurgitation increases, flow reversal

Deceleration Time Regurgitation

Fig. 16. The regurgitant orifice area or EROA represents the average size of the defect in the aortic valve during diastole and is proportional to regurgitant severity. The regurgitant volume across the aortic valve may be calculated as the difference between the LVOT volume and the transmitral volume, assuming there is no significant mitral regurgitation (see Fig. 15).

Fig. 16. The regurgitant orifice area or EROA represents the average size of the defect in the aortic valve during diastole and is proportional to regurgitant severity. The regurgitant volume across the aortic valve may be calculated as the difference between the LVOT volume and the transmitral volume, assuming there is no significant mitral regurgitation (see Fig. 15).

Diastolic Flow Reversal Aortic

Fig. 17. Aortic flow reversal. Diastolic flow reversal can be seen in significant aortic regurgitation by Doppler interrogation of flow in the aortic arch and descending thoracic aorta. In this pulsed wave Doppler envelope, the regurgitant flow velocities almost equal those of systolic forward flow—a feature indicative of severe aortic regurgitation.

Fig. 17. Aortic flow reversal. Diastolic flow reversal can be seen in significant aortic regurgitation by Doppler interrogation of flow in the aortic arch and descending thoracic aorta. In this pulsed wave Doppler envelope, the regurgitant flow velocities almost equal those of systolic forward flow—a feature indicative of severe aortic regurgitation.

becomes sustained throughout diastole at velocities exceeding 20 cm/s. Criteria for flow reversal have been established in the distal aortic arch. Significant sustained reversal in the abdominal aorta is also a sensitive sign of severe aortic regurgitation.

Individuals with severe aortic regurgitation may exhibit altered mitral flow patterns. Because aortic regurgitation results in elevated diastolic left ventricular pressures and mitral inflow ceases early in diastole, this can lead to shortened mitral deceleration times. For this reason, the

Chapter 12 / Aortic Regurgitation

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Responses

  • Lily
    How to calculate regurgitant fraction?
    3 years ago
  • patrick
    What is diastolic flow reversal aorta?
    5 months ago
  • sheryl
    What causes flow reversal in the descending aorta with severe aortic regurgitation?
    2 months ago

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