Electrocardiographic alterations in a dog with pulmonary valve stenosis, before and after enalapril maleate and atenolol therapy

Abstract

The pulmonary valve stenosis is a congenital heart malformation characterized by impairment in the outflow of the right ventricle leading to clinical signs of congestive heart failure (CHF). Therefore, the objective was to report the electrocardiogram (ECG) changes of a female 8 months old dog, poodle, with asymptomatic stenosis of the pulmonary valve before and after therapy the basis of enalapril and atenolol. Physical examination was observed tachycardia and pulmonary systolic murmur grade V / VI and tricuspid grade III / VI, with the diagnosis confirmed through radiographic, ECG and echocardiographic examinations, and therapy based on enalapril maleate (0.50 mg / kg) once daily and atenolol (0.25 mg / kg) every 12 hours, both orally. Initially, the ECG showed sinus tachycardia (250 bpm) and an increase in amplitude of the waves PmV, SmV and TmV, suggesting atrial and right ventricular myocardial hypoxia, cardiac axis deviation to the right. At 15, 90, 120 and 210 days of therapy subsequent ECGs showed sinus rhythm with a gradual reduction in heart rate and amplitude values of P waves, S and TmV. The changes described suggest improvement of the electrocardiographic tracing due to the reduction in pre-and post-cardiac load, obtained through therapy. Therefore, we concluded that the ECG performed during the seven months subsequently showed electrocardiographic changes that demonstrate the benefits of therapy based on enalapril maleate associated with atenolol in the dog with pulmonary valve stenosis. Keywords: Cardiopathy, congenital, electrocardiogram, dogs.