What we believed to be a right upper pulmonary vein by transthoracic echocardiography is actually a right lower pulmonary vein.

The most well-displayed PV in an apical four-chamber view by TTE was not the RUPV but the RLPV which showed the smallest angle of incidence toward the LV apex. The RLPV is suitable for evaluation of PV velocity to assess LV diastolic function.