Estenose de valva mitral associada a um trombo na aurícula esquerda em cão / Mitral valve stenosis associated with a left auricle thrombus in a dog

ABSTRACT

Background: Mitral valve stenosis is a congenital or acquired condition characterized by the narrowing of the orifice of the mitral valve of the heart. It causes flow obstruction and inadequate left ventricular filling, leading to increased left atrial pressure, left atrial and auricle enlargement, pulmonary venous congestion, and left-sided congestive heart failure. Mitral valve stenosis is extremely rare in dogs, and mitral valve stenosis associated with thrombus is even less common in this species. The etiology of thrombus development in mitral valve stenosis in dogs is still not clear. In human beings, mitral valve stenosis associated with thrombus has been related to rheumatic fever. This paper aims to report a case of mitral valve stenosis associated with a left auricle thrombus in a dog.Case A small mixed-breed, 9-year-old, spayed female dog was received by the emergency service of the veterinary hospital a few hours after a syncopal episode. The dog presented dyspnea, apathy, and appetite loss for a week. At physical examination, the dog had pale and cyanotic mucous membranes, 92 mmHg systolic blood pressure, 7% dehydration, and 36.9°C rectal temperature. Cardiac auscultation revealed tachyarrhythmia and diastolic murmur grade IV/VI on the left cardiac apex. During pulmonary auscultation, bilateral crackles were noted. Electrocardiography showed sinus tachycardia with supraventricular tachycardia episodes, increased P wave amplitude and duration, and increased QRS complex duration. Generalized cardiomegaly was noted in thoracic radiography with enlarged left atrium, left cardiac edge bulging, pulmonary hypertension and congestion signs, as well as areas of pulmonary opacification.[...]