Mensuração radiográfica do átrio esquerdo de cães com e sem doença mixomatosa valvar mitral

Abstract

Myxomatous mitral valve disease (MMVD) is the most prevalent acquired cardiac condition in dogs and a leading cause of congestive heart failure. Early differentiation between stages B1 and B2 is crucial, as stage B2 represents the critical point for initiating therapies that slow disease progression. This study evaluated quantitative radiographic methods (VHS, TIHS, VLAS, RLAD, M-VLAS, and TILAS) to measure the left atrium and assist in the diagnosis and staging of MMVD. Ninety dogs were analyzed, including 80 with MMVD (stages B1, B2, and C) and 10 controls, using thoracic radiographs and echocardiography. RLAD, M-VLAS, and VLAS demonstrated good sensitivity and specificity in detecting left atrial enlargement, with significant correlation to the LA/Ao ratio. For distinguishing between stages B1 and B2, RLAD and VLAS showed good sensitivity with cutoff values of 1.8v and 2.2v, respectively. TILAS showed promising potential for evaluation, particularly in dogs with vertebral abnormalities, though further studies are necessary to validate its applicability. The reliability and reproducibility of these radiographic methods reinforce their clinical utility, especially in settings with limited access to echocardiography. However, integration with clinical and echocardiographic data remains essential for accurate diagnosis and effective monitoring of MMVD progression.