A case of syncope suspected to be caused by a pancreatitis complication in a dog with pulmonary hypertension

Abstract

A thirteen-year-old, unneutered male Shiba with syncope during urination visited our small animal hospital. The dog showed tachypnea and facial edema. A right ventricular dilatation, an increase in diameter of pulmonary arteries and interstitial opacities in precordial area were observed by a chest X-ray. Several findings including tricuspid valve regurgitation, flattened interventricular septum and left ventricular (LV) diastolic dysfunction were observed in an echocardiography. On the basis of these results, the dog was suspected to have a cardiogenic syncope caused by pulmonary hypertension (PH) and subsequent low cardiac output or a neurally mediated syncope. While the LV diameter was increased in response to the treatments, the dog showed abdominal tenderness after fed a nutrient-rich diet. An abdominal ultrasound examination revealed hyperechogenic pancreas. In addition, lipase activity and C-reactive protein levels in blood were increased, suggesting a complication by pancreatitis. Then, a decrease in fractional shortening (FS) and syncope were simultaneously observed. After the dosage of inotropic drug was increased and the food was changed to a low-fat diet, the decrease in FS and the abnormal values in the blood test were ameliorated. Moreover, the syncope was not observed. In this dog, although hemodynamics tended to be improved in response to the treatments for PH and heart failure, the complication by pancreatitis possibly caused a vasovagal reflex and systolic dysfunction, which led to the syncope. It is suggested in an animal with severe circulatory disturbance that the complications which could affect hemodynamics may exacerbate the pathophysiological condition of the cardiovascular diseases.