Echocardiographic characteristics and methods of therapeutic correction of pulmonary hypertension syndrome in dogs

Abstract

Echocardiographic characteristics of the severity of pulmonary hypertension syndrome and methods of therapeutic correction in dogs are discussed. The research targets were 54 dogs of various breeds and crossbreeds of the age from 3 months to 12 years, of different sexes with clinical signs of a heart disease. All sick animals had typical clinical signs of heart disease: physical inactivity, dyspnea, and coughing. Pulmonary hypertension was diagnosed in 54 dogs (100%). Echocardiographic examination revealed congenital heart defects in 13 dogs (24.1%) (pulmonary artery stenosis, tricuspid valve dysplasia, open oval window, atrial septal defect), and acquired myxomatous mitral valve degeneration in 41 dogs (75.9%) as the causes of pulmonary hypertension. The main echocardiographic sign was the presence of tricuspid regurgitation of more than 3 m/s (pressure above 36 mmHg). All dogs were treated with a single clinical protocol aimed at improving hemodynamics including Pimobendan, Furosemide and Spironolactone. Sildenafil, a selective phosphodiesterase-5 (PDE-5) inhibitor, was added to the dogs of the first group, 10 dogs (18.5%), to correct pulmonary hypertension. The second group, 25 dogs (46.3%), was supplemented with Beraprost sodium, and the animals of the control group, 19 dogs (35.2%), were treated according to the generally accepted scheme. The immediate long-term treatment outcomes were evaluated in 3, 6, and 12 months. The evaluation criterion was the dynamics of changes in the general echocardiographic parameters of the heart: tricuspid regurgitation, normalization of pressure in the pulmonary artery, absence of atrial dilation, improvement in the right ventricular ejection fraction and the ratio of the diameter of the right ventricle to the diameter of the left ventricle. A decrease in pressure in the pulmonary artery (25 mmHg) and its branches, the right atrium, and an improvement in the right ventricular ejection fraction (45%) were found. The clinical equivalent of an improvement in echocardiographic parameters and assessment of pulmonary hypertension was an improvement in quality of life: an improvement in general condition, increased exercise tolerance and a decrease in cough.