The follow-up of patients with mitral and tricuspid regurgitation is important for their clinical treatment. We aimed to evaluate the reproducibility of the flow convergence method in mitral and tricuspid regurgitation.

The proximal flow convergence region was imaged with color Doppler ultrasound scanning echocardiography in 83 patients with mitral regurgitation, tricuspid regurgitation, or both. Proximal isovelocity surface area radii for aliasing velocities of 27 to 29 cm/s and 41 to 43 cm/s were repeatedly measured by the same experienced investigator on different days and by experienced and less experienced investigators at 1 day.

In mitral regurgitation, the intraobserver variability rate was 0.2% ± 13.5% (2.8% ± 13.3%) and the interobserver variability was 0.1% ± 13.8% (1.7% ± 18.0%) for an aliasing velocity of 27 to 29 cm/s (41–43 cm/s). For the aliasing velocity of 27 to 29 cm/s (41–43 cm/s), the 95% ranges for change of the proximal isovelocity surface area radii were ± 2.7 mm (± 1.8 mm) for measurements repeated by the same investigator and ± 2.7 mm (± 2.4 mm) for different investigators. Interobserver variability was independent of the investigators' experience. Similar data were achieved in tricuspid regurgitation.

The proximal flow convergence method is acceptably reproducible in mitral and tricuspid regurgitation independent of the investigators experience. For the aliasing velocity of 27 to 29 cm/s (41–43 cm/s), the proximal isovelocity surface area radius has to change for >2.7 (2.4) mm before an altered severity of mitral or tricuspid regurgitation in a single patient can be assumed.