Use of the Vertebral Heart Score in Coughing Dogs with Chronic Degenerative Mitral Valve Disease

Abstract

ABSTRACT. The objective of the present study was to evaluate the usefulness of the vertebral heart score (VHS) in coughing dogs with chronic degenerative mitral valve disease (MVD). Survey thoracic radiographs of 90 dogs with a history of cough and clinical and echocardiographic evidence of MVD were evaluated by 2 independent observers. The observers were asked to first determine the origin of the cough as cardiac, non-cardiac or mixed and then to measure the VHS. Agreement regarding diagnosis of the origin of cough was obtained (kappa=0.64) in 69 dogs. Of these 69 dogs, 28 (41%), 32 (46%) and 9 (13%) had a cough of cardiac, non-cardiac and mixed origin, respectively. The dogs with a cough of non-cardiac origin had a significantly lower VHS (mean ± SD, 11 ± 0.9) compared with those of dogs with a cough of cardiac or mixed origin (12.8 ± 1 and 12.9 ± 0.9, respectively). Receiver operating characteristic curve analysis showed that a VHS ≤ 11.4 is fairly accurate for exclusion of a cough of cardiac origin in dogs with MVD. The results indicate that the VHS may be an additional tool for differentiating the origin of cough in dogs with MVD. KEY WORDS: canine and feline, cardiology, echocardiography, heart, radiology.J. Vet. Med. Sci. 71(1): 9-13, 2009The term "cardiac cough" is frequently used in the clinical setting as well as in veterinary textbooks to define the origin of cough in dogs affected by cardiac disorders. Chronic degenerative mitral valve disease (MVD) with associated mitral regurgitation (MR) is the most common canine cardiovascular disease [5] and coughing is the most common presenting complaint in dogs with MVD [10]. This symptom may be related to different pathophysiological mechanisms secondary to cardiac dilatation and dysfunction caused by MVD. Among the main consequences of MVD are dorsal elevation and compression of the trachea and/or dorsal elevation of the left main stem bronchus by the dilated left atrium, pulmonary congestion and pulmonary interstitial and/or alveolar transudate secondary to increased pulmonary capillary pressure [10]. The above mechanisms may be responsible for cough in dogs with MR [2]. Nevertheless, cough can be a consequence of different respiratory disorders that may concurrently affect dogs with MVD [1]. In particular, the same dogs (i.e., small or middle-sized, aged dogs) most commonly affected by MVD are predisposed to some respiratory disorders leading to cough (e.g., chronic bronchitis, lower airway collapse and interstitial lung disease) [12,21,24]. Thus, both respiratory and cardiac diseases may contribute to cough in some cases.The vertebral heart score (VHS) is a method for objectively evaluating the dimensions of the cardiac silhouette in thoracic radiograms and was first described by Buchanan and Bücheler in the dog [7]. Using this method, the cardiac long and short axis are measured on the lateral thoracic view and are then compared with the thoracic spine. The VHS is the vertebral scale sum of the long and short axes, each measured caudally from the crania...

Risk Factors for Coughing in Dogs with Naturally Acquired Myxomatous Mitral Valve Disease

“…Left atrial size represents another potentially important cofactor for the presence of coughing in dogs affected by MMVD, and this is supported by the increased risk in dogs with increased LA size, observed on thoracic radiography or echocardiography. This finding supports previous observations that bigger than normal hearts can exert a mechanical dorsal pressure on the airways with subsequent stimulation of coughing receptors . Such pressure, however, may not be the primary cause of bronchial collapse, as indicated in a study in which the association between LA enlargement and airway collapse was not confirmed in dogs with MMVD …”

Radiographic Heart Size and Its Rate of Increase as Tests for Onset of Congestive Heart Failure in Cavalier King Charles Spaniels with Mitral Valve Regurgitation

“…Although the area under the ROC (AUROC) curve or plot is the best summary of the accuracy of a diagnostic test, and AUROC can be used to compare tests done on the same or similar patient groups, it cannot directly be used to determine the effect of a test result on the individual patient . Vertebral heart scale (VHS) as a measurement of heart size discriminated between CHF and noncardiac causes of coughing in dogs with MR, with an AUROC of 0.92 . A value of 1.0 is a perfect test and 0.5 is no better than chance.…”

“…11 Vertebral heart scale (VHS) as a measurement of heart size discriminated between CHF and noncardiac causes of coughing in dogs with MR, with an AUROC of 0.92. 12 A value of 1.0 is a perfect test and 0.5 is no better than chance. A diagnostic test should be done when the pretest probability of the condition being present is between thresholds for treating the disease in question or ruling out the condition.…”

Establishment of Vertebral Heart Scale in the Growth Period of the Japanese Macaque (Macaca fuscata)

“…While puppy VHS does not change [9], kitten VHS decreases with growth [1]. Furthermore, VHS is known to be increased in coughing dogs compared with non-coughing dogs [2]. In non human primates, only one report has described VHS in the common marmoset (9.42  0.44v) [10].…”

“…VHS has proven useful as an easily measured and relatively objective value [3]. In dogs, studies of VHS in puppies, adult dogs and different breeds have been performed [2][3][4][5]9]. Less research into VHS has been performed for cats than for dogs, although studies comparing kittens and adult cats have been reported [1,6].…”