2-D Echocardiologic study of morphology of mitral valve and its apparatus in Malteses

• Main Authors: Ying Qiao, 喬穎
• Other Authors: Feng-Pang Cheng
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/11522612223355943372

碩士 === 國立中興大學 === 獸醫學系暨研究所 === 101 === Mitral regurgitation (MR) is currently the most common heart disease in aging dogs. Drug is still the primary treatment using by severe MR dogs for palliative purpose other than fundamentally solving the problem. Surgical procedures, such as mitral valve repair or replacement, which have been successfully carried out on many CHF dogs, can thoroughly remove the direct reason. This surgery, however, is difficult and can hardly be done on mini companion dogs for its small heart. Recently, the development of interventional techniques makes it possible to replace the mitral valve of severe MR mini dogs by a new non-surgical procedure, off-pump transapical mitral valve replacement. The current study is to measure and analyze the basic physiological data and mitral valve’s morphological values at different pathological stages of most popular mini companion dog in Taiwan — Malteses dogs, which may get some useful information for carrying out off-pump transapical mitral valve replacement in these dogs in the future. According to the data, there is closely relation between severity of mitral valve degeneration and dog’s age, the older the dog, the more serious of the disease. The severity of mitral valve degeneration is also correlated with VHS, the VHS of dogs at Stage B2 and Stage C is significantly higher than that of Stage A and Stage B1 (p<0.05). This indicate VHS is useful in diagnose of MR disease. Using 2-D echocardiography, we measured and analyzed the basic mitral valve’s morphological values of Malteses dogs at normal or different pathological stages. The findings are as follows: except the Stage B1, the diameter of mitral valve of sick dogs is significant longer than healthy dogs by either R4 section, RO or L4 section (P <0.05); the length of mitral valve diameter is shortest at RO section; the length of anterior and posterior mitral valve of dogs at Stage B2 and Stage C is markedly longer than Stage A and Stage B1 (p<0.05), and the difference between Stage A and Stage B1 is not significant; the anterior chordae tendineae is notably longer than posterior in normal dogs (P<0.05) , but in sick dogs their difference is not marked; the annulus value and area are increased compared with normal dog, the change, however, is not notable (P>0.05). In summary, the mitral valve morphology of severe MMVD Malteses dogs had significant changed, diameter is lengthened, valve leaflets is widened, chordae tendineae is elongated, and circular and area are increased. These are all must be carefully considered during the designing of mitral valve stent or the procedure of off-pump transapical mitral valve replacement in mini dogs in the future.