Case Study

Bradycardia of unknown etiology and minimal mitral insufficiency in a 1 year old FS Toy Poodle

A 1-year-old female spayed toy poodle dog presented for evaluation of bradycardia. Blood pressure was within normal limits. Survey thorax radiographs showed normal size and shape of the cardiac silhouette and left atrium. The vertebral heart sum was 10.2, and a mild interstitial lung pattern was noted.

A 1-year-old female spayed toy poodle dog presented for evaluation of bradycardia. Blood pressure was within normal limits. Survey thorax radiographs showed normal size and shape of the cardiac silhouette and left atrium. The vertebral heart sum was 10.2, and a mild interstitial lung pattern was noted.

Sonographic Differential Diagnosis

The only abnormality seen in this patient (besides some minimal mitral dysplasia causing subclinical mitral insufficiency) is bradycardia. HR was between 64/min and 120/min during the examination procedure. This heart rate should not cause any clinical symptoms.

Image Interpretation

The mitral valve leaflets look normal on 2D although there is a very small insufficiency jet noticed on color Doppler. No other abnormalities are seen. No evidence of a shunt.

DX

Bradycardia of unknown etiology and minimal mitral insufficiency

Outcome

A conventional ECG (at least 2 minutes duration) would be recommended to see if there is heart block present (most probably SA, AV-Block Grade 1, since there was no AV Block Grade 2 on the echo clips.)

Comments

Anesthesia should not be a concern for this dog. Atropine could be considered as part of the premedication, or could be given in the event of bradycardia.

Clinical Differential Diagnosis

Primary conduction anomaly (AV/SA block), excessive vagal tone (GI tract, respiratory disease, CNS lesion, cervical spine lesion), hyperkalemia, hypothyroidism, organophosphate toxicity.