Clinical and echocardiographic follow-up study in warm-blood horses with heart valve insufficiency

The present study compares the clinical and echocardiographic findings of two cardiological examinations in 31 warm-blooded horses performed in a time interval varying from two to eight years. The horses were used as performance, pleasure, and posture horses. Their mean age was 12 years. Twenty-five patients showed a mitral valve insufficiency, which was combined with an insufficient tricuspid valve in I I horses and with an aortic valve insufficiency in 5 horses. Four horses showed only an insufficient tricuspid valve and 2 horses had an only an aortic valve insufficiency. Some of the parameters of the two-dimensional echocardiography were significant progressive. The dimensions of the right and left atrium and the left ventricle increased significantly. In almost all horses with mitral valve insufficiency a significant enlargement of the left atrium could be observed. With conventional and colour flow Doppler echocordiography the hemodynamic consequences of a heart valve deficiency were assessed and there was a tendency towards a mild increase in regurgitant volume and enlarged vena contracta (regurgitant orifice). The echocardiographicaly decreased heart valve functions did not result in a deterioration of the cardiac condition in most cases. Thus the changes of echocardiographic parameters, observed in our study, seems not to be of clinical relevancy in all cases. In this study the progression of heart valve insufficiency did not show any correlation to the age, the performance and the severity of the cardiac disease of the horses. The results of this study show that almost all 31 patients were able to compensate heart valve disease during the period of two to eight years in spite of a mild deterioration of some echocardiographical parameters.