PMC9840789_01
A) Lateral chest radiograph depicting cardiomegaly (4.50 inter-costal space and 12 vertebral heart score) and increased sternal contact with mild pleural effusions. B) Dorso-ventral view of chest depicting a bulge at 9:00 to11:00 o'clock (black curve line) confirming right atrial enlargement
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F1
Lateral radiograph revealed globoid appearance of heart occupying 4.50 inter-costal space along with increased sternal contact of heart and mild pleural effusions (Fig. 1A). The DV view also revealed a bulge at 9:00 o'clock to 11:00 o'clock indicating right atrial enlargement (Fig. 1B).
Electrocardiography at 50.00 mm sec-1 paper speed and 10.00 mm mV-1 sensitivity showing very small inverted P waves, deep S waves in leads I, II, III and aVF suggesting junctional tachycardia with ectopic foci and right ventricular enlargement, respectively. Also, splintered QRS complexes in lead III suggest right atrioventricular valve malformation with tachycardia (heart rate: 250 bpm)
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F2
S waves in leads I (0.30 mV which was more than normal 0.05 mV), II (0.90 mV which was morethan normal 0.35 mV), III (0.60 mV) and augmented vector foot (aVF; 0.80 mV), (Fig. 2). Splintered QRS complexes were also visible in lead III being indicative of right AV valve malformation (Fig. 2).
A
) Right parasternal long axis view depicting tricuspid regurgitation. LV: left ventricle, RV: right ventricle, LA: left atrium, and RA: right atrium. B) The ratio of RA: LA was 2.07 from right parasternal long axis view
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F3
When color Doppler was applied in the same view, severe tricuspid regurgitation was observed (Fig. 3A). Using this right parasternal view to assess the severity of Ebstein's anomaly, RA: LA was measured which was calculated to be 2.07 depicting that RA was transversely dilated because its ratio was more than one (Fig. 3B).
Compartmentalization of right ventricle into functional and atrialized RVs due to tricuspid valve dysplasia being seen from left apical four chamber view. Displacement index was calculated by measuring the distance between hinge point of septal mitral leaflet and hinge point of septal displaced tricuspid leaflet and dividing the value by body surface area of dog (30.40 mm m-2). Also, distance from apex to septal mitral annulus (AM) to distance from apex to displaced tricuspid leaflet annulus (AT) ratio was 1.26. LV: left ventricle, RV: right ventricle, LA: left atrium, and RA: right atrium
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F4
Then, in left apical four chamber view, tricuspid valve leaflets were seen apically displaced dividing the RV into atrialized and functional portions of RV (Fig. 4). Displace-ment index was also calculated from the same view which is the distance between the hinge point of mitral valve leaflet to the hinge point of displaced tricuspid septal leaflet at end-diastole divided by body surface area of animal (Fig. 4). Also, ratio between the distance from apex to the septal anterior mitral leaflet hinge point (AM) to the distance from apex to septal displaced tricuspid leaflet hinge point (AT) was calculated which came out to be 1.26 that was greater than normal value of less than 1.00 (Fig. 4).