Fig. 1

Two-dimensional echocardiographic image of the heart of a dog with severe pulmonary hypertension and ruptured chordae tendineae of the tricuspid valve. A 4-chamber view from the standard left parasternal caudal window. On the left of the image is the right side of the heart with the right atrium (RA) on the bottom and the right ventricle (RV) on the top of the image. On this systolic frame, the flail anterior leaflet of the tricuspid valve can be appreciated in the right atrial lumen causing lack of valvular coaptation, whereas the mitral valve is closed (v). Asterix (*) indicates the opening between the tricuspid valve leaflets. On the flail leaflet, remnants of ruptured chords can be recognized (>). In addition, severe right atrial dilatation, compared to the normal sized left atrium (LA) can be appreciated. The right ventricle shows a severe concentric and eccentric hypertrophy (thickened wall and dilated lumen), whereas the left ventricular lumen (LV) is small, and the wall shows pseudohypertrophy because of underfilling. S = interventricular septum. Synchronous ECG shows a sinus rhythm with negative QRS-complexes, presumably because of a right-sided deviation of the mean electrical axis as a result of right ventricular hypertrophy