Use of sildenafil citrate in a cat with Eisenmenger's syndrome and an atrial septal defect

Abstract

A 2-year-old male neutered Siamese cat presenting with weakness and dyspnoea was diagnosed with an atrial septal defect and pulmonary hypertension, which resulted in right-to-left shunting (Eisenmenger's syndrome). The cat was treated with sildenafil (0.25-0.6 mg/kg) for 10 months. There were no apparent treatment-related adverse effects. Improvement in clinical signs was noted, although increasing doses of sildenafil were required. After 10 months the cat significantly deteriorated and was euthanased.

Figure 1

Right (R) lateral recumbent radiograph of the thorax, day 1. Note the cardiomegaly and dilated, tortuous pulmonary lobar arteries

Figure 2

Ventrodorsal thoracic radiograph, day 1. L = left

Figure 3

Right parasternal four-chamber view. Note the high-septal atrial septal defect, right ventricular (RV) concentric hypertrophy, right atrial (RA) enlargement, and severely dilated right pulmonic artery (PA). LV = left ventricle; LA = left atrium

Figure 4

Right parasternal four-chamber view with colour Doppler interrogation of the atrial septum. Note the right-to-left shunting through the atrial septum defect (ASD) just before the onset of the QRS complex on the electrocardiogram. LA = left atrium; RA = right atrium

Figure 5

Right parasternal short axis view with continous wave Doppler interrogation of the pulmonic valve. Note the signal associated with pulmonic insufficiency that is directed towards the probe

Figure 6

Right parasternal short axis view showing pulmonic valvular insufficiency. PA = pulmonary artery; Ao = aorta; LA = left atrium