Unilateral atrial ectopic rhythm in a golden retriever

ABSTRACT

Background: Atrial ectopic rhythm is a type of supraventricular arrhythmia, originating in two distinct points in the atrialregion. In the electrocardiographic (ECG) tracing, it is represented by independent depolarizations of sinus P waves andectopic P waves. The occurrence of this disorder is rare, and the diagnosis criteria are the presence of the described waveswithin the basal rhythm. In humans, there have been reports related to severe heart failure with an unfavorable prognosis.The present report aimed to describe the clinical case of a dog with unilateral atrial ectopic rhythm without any underlying cardiac disorder.Case A 8-year-old male golden retriever was brought to a veterinary clinic for a preoperative evaluation for lipoma removalin the right forelimb. On clinical examination, the owner stated that the patient was active, with no signs of easy fatigueor cough. The canine displayed normophagy, normodipsia, normoquezia, and normouria. On physical examination, hedemonstrated a lymphatic temperament with tachypnea. The temperature and capillary filling time were within the normalrange, with a normokinetic pulse. Cardiac auscultation revealed a mild grade I/VI murmur in mitral focus and an 80-bpmheart rate. Respiratory auscultation revealed the presence of harshy lung sounds. The cough reflex was positive; the Piparotetest, negative. The blood test showed no noticeable changes in blood count and serum biochemistry. Systemic systolicblood pressure was 120 mmHg. On radiographic examination, no evidence of heart or lung abnormalities were identified.After the clinical evaluation, an ECG examination was performed; a unilateral atrial ectopic rhythm was observed withdifferent frequencies between atrial and ventricular rhythm and with P (164°) and P waves (80°). On echocardiographic...