Cardiac Manifestations of Trypanosoma cruzi Infection in a Domestic Dog

Figures

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  Figure 1. Transthoracic echocardiographic images obtained in a dog seropositive for T cruzi from a right parasternal short-axis view of the left ventricle (LV) in two dimensions and M-mode at initial presentation (A, C) and at recheck evaluation 15 months later (B, D). The left ventricular internal dimensions at initial presentation were within normal limits, and ejection fraction was at the low end of the reference range. The right ventricle (RV) was mild to moderately dilated. At recheck evaluation, the left ventricular diastolic dimension was unchanged, and the systolic dimension had increased. The RV was severely dilated. The associated electrocardiogram shows a sinus rhythm conducted with a RBBB in all panels and a single ventricular premature beat in (A).

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  Figure 2. Transthoracic echocardiographic images from the same dog in Figure 1 comparing right parasternal (A, B) and left apical (C, D) four-chamber views obtained at initial presentation (A, C) and at recheck evaluation 15 months later (B, D). Thinning at the apex of both ventricles can be appreciated (arrows in A and B). Progressive right ventricular dilation is best appreciated in the left apical long-axis view. The associated electrocardiogram shows a sinus rhythm conducted with a RBBB in all panels. LV, Left ventricle; RV, right ventricle.

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  Figure 3. Transthoracic echocardiography of tricuspid annular plane systolic excursion (TAPSE) determined by M-mode at the lateral tricuspid annulus from a left apical four-chamber view to demonstrate a reduction from the initial evaluation to the 15-month recheck.

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  Figure 4. A resting six-lead electrocardiogram obtained without sedation approximately 5 months following initial presentation. Lead II demonstrates an underlying sinus rhythm (arrow) conducted with a RBBB and first-degree atrioventricular block. Premature ventricular complexes (asterisk) are of varying morphology. Paper speed 25 mm/sec, amplitude 10 mm/mV.