Page 269 - Feline Cardiology

276 Section G: Congestive Heart Failure

A C

Congestive Heart Failure

B D
Figure 19.11. Thoracic radiographs of a cat with severe pleural effusion and severe unclassified cardiomyopathy.
Thoracic radiographs including right lateral (A) and dorsoventral (B) projections of this severely dyspneic cat, show marked pleural
effusion that obscures the cardiac silhouette. The lung lobes are scalloped and retracted from the thoracic wall, with rounded edges
suggesting chronicity of pleural effusion. There is dorsal deviation of the trachea, which is not specific for cardiomegaly in the face of
severe pleural effusion. Immediately after thoracocentesis, right lateral and ventrodorsal projections show mild residual pleural effusion
(C) and (D). Biatrial dilation and severe cardiomegaly are present, as well as moderate, patchy to diffuse pulmonary infiltrates consistent
with pulmonary edema.

absence of pulmonary venous distension, but its pres- thoracic wall, and obscured diaphragmatic and cardiac
ence increases the suspicion of CHF. There is often a silhouettes (see Figures 19.10–19.12). It is often impos-
mixed pattern of pulmonary edema and pleural effusion sible to visualize the cardiac silhouette and pulmonary
in feline congestive heart failure (Figure 19.10). In a large vasculature due to the presence of significant pleural
study of cats diagnosed with HCM, pulmonary edema effusion and/or pulmonary edema. Dorsal displacement
was present in 66% of cats and was the cause of dyspnea of the trachea may be present in cats with moderate or
in 86% of cats with heart failure, as opposed to only 14% severe pleural effusion regardless of cardiac size and is
of cats that were dyspneic due to severe pleural effusion not an indicator of cardiomegaly in cats with significant
(Rush 2002). pleural effusion (Snyder 1990).
Pleural effusion is easily identified by thoracic radio- As long as the cardiac silhouette is not obscured
graphs, with radiographic characteristics that include: by pulmonary edema or pleural effusion, cardiomegaly
radiopaque fluid accumulation outside the pulmonary is almost always detected in cats with congestive heart
parenchyma, pleural fissure lines, scalloping (rounding) failure. Measurement of vertebral heart size may be
of the lung lobes, retraction of the lung lobes from the useful to quantify cardiac size and determine whether