Malignant pheochromocytoma presenting as a bradyarrhythmia in a dog
Version of Record online: 24 APR 2007
Journal of Veterinary Emergency and Critical Care
Volume 17, Issue 2, pages 164–169, June 2007
How to Cite
Brown, A. J., Alwood, A. J. and Cole, S. G. (2007), Malignant pheochromocytoma presenting as a bradyarrhythmia in a dog. Journal of Veterinary Emergency and Critical Care, 17: 164–169. doi: 10.1111/j.1476-4431.2006.00214.x
- Issue online: 24 APR 2007
- Version of Record online: 24 APR 2007
- adrenal gland;
- magnetic resonance imaging
Objective: To describe a case of atrioventricular block and syncope secondary to systemic hypertension in a dog with malignant pheochromocytoma.
Case Summary: A 13-year-old spayed female mixed-breed dog presented following an acute onset of collapse. The dog was hypertensive and had paradoxical high-grade second-degree atrioventricular block with concurrent syncope. Initial emergent therapy included a nitroprusside infusion for the systemic hypertension and vagolytic therapy for the bradyarrhythmia. A left adrenal mass was seen on abdominal ultrasound and was further characterized by MRI. Following medical stabilization with phenoxybenzamine and propantheline, a left adrenalectomy was performed. Histological diagnosis was consistent with a malignant pheochromocytoma. Following tumor removal there has been no further hypertension, atrioventricular block or syncope.
Unique information provided: This is the first documented case of a malignant pheochromocytoma presenting as syncope secondary to hypertension induced atrioventricular block.