PEDOF PROBE MEASUREMENT OF PEAK VELOCITY AVOIDS MISCLASSIFICATION OF AORTIC STENOSIS SEVERITY IN TWENTY-FIVE PERCENT OF PATIENTS WITH AORTIC STENOSIS

PURPOSE The constraint of time allotted to perform echo examinations, and continuous miniaturization and improvement of signal-to-noise ratio of modern combined imaging and Doppler transducers (steerable) have forced some echocardiographers to assess aortic jet velocity signal using only steerable transducers (ST). The accuracy of aortic jet peak velocity measured using modern ST in comparison with Pedof probe (PP) has never been tested.
METHODS We studied 58 consecutive pts (62% M, 62 ± 14 yrs) with moderate-severe AS (Peak gradient= 64 ± 32 mm Hg, EOA= 0.92 ± 0.35 cm2). Each pt was searched for highest possible transaortic velocity using CW modality form apical and right parasternal approach using ST and PP in random order. Feasibility was 100% and 83% using ST and 93% using PP from apical and right parasternal approach, respectively.
RESULTS

	Steerable	Pedof	PValue
Vmax Apical (m/s) Vmax Right Intercostal (m/s)	3.76±0.8 3.76±0.97	3.66±0.8 4.04±0.99	0.02 <0.0001
PValue	0.82*	<0.0001*	<0.0001^
Peak Gradient Apex (mmHg) Peak Gradient Right Intercostal (mmHg)	53±24 56±30	52±26 66±33	0.68 <0.0001
PValue	0.23*	<0.0001*	<0.0001^
EOA Apex (cm2) EOA Right Intercostal (cm2)	0.96±0.36 0.96±0.41	0.99±0.38 0.89±0.36	0.034 0.001
PValue	0.37*	<0.0001*	<0.0001^

*Apical vs right intercostal approach; ^ ST from apex vs PP from right intercostal approach
Using ST only, 3 pts out of 5 (60%) would have been misclassified as mild instead of moderate AS, and 10 pts out of 18 (55%) would have been misclassified as moderate instead of severe AS.
CONCLUSIONS PP and ST measure comparable peak flow velocities through the AV from the apical approach however PP allows recording of higher velocities from right parasternal approach. Using the right intercostal approach and PP avoid misclassification of AS severity in 25% of pts with suspected AS.