Diagnosis And Clinical Analysis Of Canine Mitral Valve Degeneration Secondary To Atrial Hypertrophy

Degenerative mitral valve disease is the most common acquired heart disease in dogs.Degenerative lesions of the mitral valve can cause mitral insufficiency and mitral regurgitation,leading to atrial hypertrophy,severe left atrial rupture can cause sudden death.Canine mitral valve degenerative disease can account for about 80% of clinical canine heart disease,and when the disease progresses to the middle and late stages,it often causes heart failure.Heart failure is irreversible,which is also an important reason for the death of mitral valve degenerative disease in dogs.In this study,clinical cases of 24 dogs with mitral degenerative disease were studied,and 3 dogs with cardiac disease were excluded as the control group.Clinical examination,X-ray examination,electrocardiogram and echocardiography were performed.And analyze the changes of cardiac morphological structure and function in dogs with mitral degenerative disease,as well as the influence of heart failure grade,age and body weight on dogs with canine mitral degenerative disease.The results are as follows:1.X-ray examination usually shows an increase in the contour of the heart.The total contour of the heart is enlarged in 12 cases,and the left heart contour is enlarged in 6 cases,accounting for 63% and 32% of the total cases,respectively.Severely affected dog shows cloudy shadows in the lungs;2.Electrocardiogram showed 10 cases of sinus arrhythmia,accounting for 42% of the total cases;3 cases of dog P wave width increased,accounting for 13% of the total cases,1 case of dog P wave amplitude was higher than healthy dogs;15 cases of dogs with QRS complex width increased,accounting for 63% of the total cases,2 cases of dogs with QRS complex amplitude increased compared with healthy dogs;4 cases of dogs(17% of the total cases)PR interval and one case’s QT interval was longer than healthy dogs;3.Echocardiography was used to observe and measure the morphology and function of the heart.The ratio of left atrial diameter and left atrium to aortic diameter in dogs with mitral valve degeneration was significantly higher than that of the control group,and with the increase of heart failure grade,the volume and contraction function of the left atrium are also reduced,and the difference is significant;4.The left atrial diameter,left atrial and aortic ratio,and diastolic left ventricular volume of the patient dogs have a tendency to increase with age,but the difference is not significant;5.The left atrial diameter,left atrium and aortic ratio of obese dogs were significantly higher than control group.The left atrial pressure of obese dogs was significantly higher than that of standard weight dogs,and the ventricular systolic function was significantly lower than that of standard body reorganization.Conclusion: X-ray examination of patient dogs shows the contour of the whole heart increased.Most dogs have ECG results within the normal range,so ECG can not be used as the only diagnostic method for this disease.Echocardiography shows different degrees of dilatation of the left atrium and decreased cardiac systolic function;And the higher the level of heart failure,the greater the degree of left atrial and left ventricular dilatation,and the gradual decline in systolic function.Older dogs also have increased left atrial and left ventricular dilatation compared with young dogs,but age is not a factor influencing the severity of mitral degenerative disease.Obese dogs have severe left atrial dilatation and cardiac function compared with standard weighted dogs.