Detection of diastolic dysfunction: acoustic quantification (AQ) in comparison to Doppler echocardiography

Objectives. To evaluate the potential of acoustic quantification (AQ) in detection of diastolic dysfunction in comparison to Doppler analysis, we investigated, as a model of restrictive filling pattern, nonrejecting heart transplant recipients early postoperatively. Background. AQ, an ultrasonic backscatter imaging system, enables inst-antaneous calculation of cavity areas and thus provides a new approach to diastolic function. Methods. Of 27 pts who have undergone heart transplantation, echocardiography has been performed at the day of biopsy. During a time course of 8 weeks echocardiographic data have been analysed at 3 different time points (early, mid and late) in 16 nonrejecting pts. Indexes of the area-change waveform and its 1. derivative (dA/dt) obtained by AQ were opposed to usual Doppler indexes. Results. In comparing data of the early and late time point of investigation, significant changes of early diastolic filling were detectable by AQ as well as by Doppler: End-diastolic areas have increased (p<0.001), while peak filling rate (p<0.0001), slope of area change during rapid filling (p<0.001) and amount of relative area change during rapid filling (p<0.001) have decreased. Complementary, Doppler derived pressure half-time (p<0.0001) and isovolumic relaxation time (p<0.0001) have increased while the peak early filling velocity (p<0.0001) and its time velocity integral (p<0.001) have decreased. Conclusion. An initial restrictive filling pattern has improved 8 weeks postoperatively. Since multiple indexes, obtained from the area change waveforms, in particular the for end-diastolic area normalized peak filling rate, seem to be highly sensitive in detecting changes of diastolic function, AQ may play an important complementary role in non-invasive evaluation of restrictive filling pattern.