Novel handheld ultrasound with spectral Doppler modality allows for reliable valvular blood flow velocity assessment

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Handheld Ultrasonographs (HUD) have soldified their position as a entry-level echocardiographic tool tailored for introducing non-invasive imaging diagnostics to everyday clinical practice. Current approach to valve assessment with the use of HUD could only involve qualitative method based on the visual detection of morphologic abnormalities and color Doppler assessment. It was not until recently that, Quantitative analysis was enabled with the implementation of spectral doppler to the HUD. Purpose To assess if HUD featured with spectral Doppler modality enables for reliable evaluation of the valvular flow velocity. Methods 102 consecutive patients reporting to the cardiological emergency room underwent HUD examination involving both the measurement of mitral valvular flow velocity with the pulsed wave Doppler and aortic valvular flow with continuous wave Doppler. Subsequently, the same parameters were measured with the high end stationary workstation, and acquired results were treated as reference. Mitral valvular blood velocity > 1,3 m/s and atrial valvular blood flow velocity >2,0 m/s. were considered as abnormal values. Results The correlation between the measurements of maximum velocity through mitral valve obtained with the HUD and standard echocardiography was high (r=0,85; p<0,0001; 95% CI 0,78–0,89). The Bland-Altman plot showed no clinically relevant bias (mean difference 0,06 m/sec, upper limits of agreement 0,2 m/sec lower limit of agreement 0,32 m/s). Accelerated valvular blood flow (present in 4 pts) was detected with HUD with sensitivity of 75 % (95% CI: 19%-99%), specificity of % (95% CI: 96%-100%), positive predictive value of 100% (95% CI: 29%-100%), negative predictive value of 99% (95% CI: 95%-100%). Corresponding assessment of aortic valve showed the following correlation: r=0,87; p<0,0001; 95% CI 0,81–0,91). The Bland-Altman plot analysis indicated small underestimation bias of −0,17 m/sec (P < .001), upper limits of agreement of 0,47 m/sec, lower limit of agreement −0,81. Accelerated valvular blood flow (found in 7pts): sensitivity of 57% (95% CI: 19%-90%), specificity of 100% (95% CI: 96%-100%), positive predictive value of 100% (95% CI: 40%- 100%), negative predictive value of 97% (95% CI: 91%-99%). Conclusion Correlations calculated between the results of valvular blood flow measured with HUD and conventional workstation proved to be very strong. HUD examination enables for detection of accelerated blood flow through mitral and aortic valves with high positive and negative predictive value.