Fig. 3

Echocardiograms from a male, 1.2-year-old Golden Retriever dog with atrial fibrillation. a A systolic, right parasternal, long axis view demonstrating a severely enlarged right atrium with malpositioned (apically displaced) tricuspid valve leaflet insertions (arrow). b A modified left parasternal apical four-chamber view demonstrating incomplete coaptation of the tricuspid valve leaflets (asterisk). c A continuous wave Doppler signal from the left apical four-chamber view, demonstrating tricuspid insufficiency (TI) with a peak flow velocity of up to 4.26 m/s in many of the irregularly dispersed cardiac cycles. This velocity is compatible with a systolic pressure gradient of 72.6 mmHg between one of the right ventricular compartments and the right atrium. Note the “V-wave cut off” of the TI signal, suggestive of an elevated pressure in the receiving compartment. d A modified left parasternal apical four-chamber view depicting color Doppler evidence of severe TI; LA, left atrium; LV, left ventricle. RA, right atrium