Imperforate cor triatriatum dexter with patent foramen ovale and pulmonic stenosis in three dogs: Diagnostic findings and attempted surgical correction.

Three canines were identified with aberrant drainage of the caudal vena cava to the left atrium, consistent with imperforate cor triatriatum dexter, and concurrent patent foramen ovale. All three had concurrent significant pulmonic stenosis with varying degrees of hypoplasia of the right ventricular outflow tract. Echocardiography, positive contrast studies, and angiography confirmed the diagnosis. Surgical redirection of the caudal vena cava bloodflow to the right atrium was attempted unsuccessfully in two symptomatic patients. The third patient was asymptomatic, and correction was not attempted. Possible embryologic causes and possible approaches in future cases are discussed.