DIASTOLIC FORWARD FLOW IN THE PULMONARY-ARTERY IN A PATIENT WITH SEVERE TRICUSPID REGURGITATION - RELATIONSHIP TO ABSENCE OF THE CARVALLO SIGN

Inspiratory diastolic forward flow in the pulmonary artery was monitor ed by pulsed Doppler echocardiography in a patient with severe tricusp id regurgitation following closure of a sedundum atrial septal defect. An inspiratory augmentation of the regurgitant murmur was not evident in this patient (absence of the Carvallo sign). Pulsed Doppler echoca rdiography and color flow mapping revealed a decrease in both the peak velocity and flow area of the tricuspid regurgitation in the right at rium during inspiration, associated with an increased mean right atria l pressure. It is possible that a transient inspiratory elevation of t he right atrial pressure in excess of the pulmonary artery pressure ma y have resulted in diastolic forward flow in the pulmonary artery, the reby decreasing the regurgitant flow from the right ventricle to the r ight atrium, and eliminating the Carvallo sign.