Evaluation of left intraventricular flow dynamics using the novel non-contrast HyperDoppler technique

Aims: Recently, HyperDoppler, a colour Doppler-based ultrasound technique, has been introduced for left ventricular (LV) flow dynamics evaluation in clinical settings, but quantitative information derived from its use is limited. We aimed at establishing reference values and reproducibility of key HyperDoppler LV flow dynamics measures: vortex area, length, depth, intensity, and global kinetic energy dissipation (gKED) in normal subjects. We also explored the influence of physiological and echocardiographic variables on HyperDoppler measures. Methods and results: This multicentre, international study involved 13 echocardiographic laboratories and an independent echo corelab. A total of 467 normal subjects were enrolled and categorized by gender and age (20-39, 40-59, and 60-79 years): of these, 317 subjects were analysed at the corelab and 419 on-site using different colour Doppler cineloops. Corelab analysis yielded a median value (25th-75th percentile) of 25.0% (21.1-28.0%) for vortex area, 57.4% (53.3-62.6%) for vortex length, 34.3% (30.7-38.1%) for vortex depth, -31.9% (-28.0% to -35.8%) for vortex intensity, and 0.55 (0.44-0.70) for gKED. Minor age- and gender-related variations were noted in vortex length, depth, and gKED. Excellent reproducibility was shown for each HyperDoppler measure. Physiological behaviour of left intraventricular flow dynamics was adequately captured by the HyperDoppler quantitative measures. Conclusion: Reference values for left intraventricular flow dynamics were established using the HyperDoppler technique, which is reproducible and enables the assessment of intracardiac flow dynamics in clinical practice.