Image 1: modified apical 4 chamber view using transthoracic echocardiography. Slight superior angulation of the probe allows visualization of the right upper pulmonary vein (RUPV) adjacent to the interatrial septum in the posterior left atrium. Pulmonary venous doppler is best performed in this pulmonary vein, as the direction of flow will nearly parallel the incident ultrasound waves.
Image 2: illustration of the expected spectral doppler waveform derived from a single cardiac cycle with a pulsed wave doppler gate placed in the right upper pulmonary vein (RUPV). Notable features include a dominant systolic component (S/D > 1), with S1 and S2 fused, and an atrial reversal peak velocity under 35 cm/s.