Evaluation of right ventricular function with pulsed and tissue Doppler echocardiography in small breed dogs with chronic mitral valve disease

• Grant number: 12/12598-5
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2012
• End date: September 30, 2014
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Maria Helena Matiko Akao Larsson
• Grantee: Maria Helena Matiko Akao Larsson
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Chronic mitral valve degenerative disease is the result of mixomatous degeneration of mitral aparatus and represents the most common adquired heart disease in the dog. Pulmonary arterial hypertension is a complication of the chronic mitral valve disease in dogs, with 14 to 31% of prevalence. These conditions cause left atrial pressure increase and pulmonary arterial hypertension. The response of right ventricle to the increase in pulmonary vascular resistance is hypertrophy and, in some cases, dilatation, besides systolic or diastolic disfunction. It is known that right ventricular function is a primordial factor in exercise capacity and survival of patients with left cardiac disease. The right ventricular response in different stages of chronic mitral valvar disease in dogs with the use of new technologies of echocardiographic evaluation in dogs, just as tissue Doppler and new technics related to it, is not well understood, neither with nor without pulmonary hypertension. The purposes of this study are: identify the main left ventricular function echocardiographic variable related to the development of severe pulmonary arterial hypertension; compare parameters of right ventricular function in healthy dogs, in dogs with mitral valve insufficiency but without pulmonary hypertension, and dogs with mitral valve insufficiency and modest, moderate or important pulmonary arterial hypertension; correlate the echocardiographic variable of left ventricular function related to the development of important pulmonary hypertension to parameters of right ventricular function. Therefore, evaluation of pulmonary blood flow with pulsed Doppler and right ventricular function with tissue Doppler will be done. Dogs with respiratory, kidney, hepatic, endocrine diseases, cardiac arrhythmia, congenital heart diseases or cardiomyopathy will be excluded of this study. (AU)