Page 267 - Feline Cardiology

274 Section G: Congestive Heart Failure

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Congestive Heart Failure

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Figure 19.9. Thoracic radiographs of a cat with severe hypertrophic cardiomyopathy and mild left heart failure before and after medi-
cal therapy. Thoracic radiographs including right lateral (A) and ventrodorsal (B) projections of this cat show cardiomegaly with severe
left atrial dilation. Radiographic abnormalities include mild, patchy to diffuse interstitial pulmonary infiltrates and pulmonary venous
distension. The combination of these abnormalities is consistent with mild pulmonary edema and left heart failure. A week after medical
therapy with furosemide and enalapril, a recheck right lateral radiograph reveals resolved pulmonary edema and resolved pulmonary
venous distension, but persistent cardiomegaly and left atrial dilation (C).

history and physical examination, radiographs may be pulmonary venous distension, and interstitial to alveolar
the only other test necessary to make the diagnosis of pulmonary infiltrates often in the perihilar region and
heart failure in some cases. However, thoracic radio- the caudal or accessory lung lobes (Figure 19.9). However,
graphs should never be a terminal event in the fragile, radiographic appearance of congestive heart failure in
dyspneic cat. Cats should be handled as carefully as pos- cats is highly variable and may pose a diagnostic dilemma
sible to minimize stress, with the least possible restraint. for distinguishing primary respiratory disease from con-
A dorsoventral radiograph (sternal recumbency) is the gestive heart failure (Figures 19.10—19.12). Unlike dogs
least stressful view to obtain and may provide enough who develop the typical perihilar to caudodorsal distri-
information to assess whether there is severe cardiac bution of cardiogenic pulmonary edema, cats do not
disease and heart failure in the unstable patient. Ideally, develop a particular distribution pattern of edema. In a
both a lateral and dorsoventral (or ventrodorsal) views study of 23 cats with cardiogenic pulmonary edema, all
should be obtained if possible, or may be obtained once cats had interstitial infiltrates, and most had alveolar
the cat is more stable. Another option for evaluation of infiltrates (83%) in a diffuse pattern (78%) (Figures 19.9,
severe pleural effusion in the unstable, dyspneic cat is a 19.10) (Benigni et al. 2009). Interstitial infiltrates are
brief “triage” echocardiogram. Two-view radiographs caused by pulmonary edema accumulating in the inter-
should be obtained after thoracocentesis to assess cardiac lobular septa and consist of a reticular or granular hazy
size and evaluate the pulmonary parenchyma and pul- pattern (Figures 19.9, 19.10). Almost 40% of cats had a
monary vasculature. regional distribution of pulmonary edema, with ventral
Cardiogenic pulmonary edema in cats can be a per- distribution the most common (22%), followed by
plexing diagnosis to make. Classic thoracic radiographic caudal distribution (13%) and lastly hilar distribution
abnormalities include cardiomegaly and atrial dilation, (4%) (Benigni et al. 2009). Mild edema initially accu-