title: Possible sources of right-to-left shunting in patients following a total cavopulmonary connection.
abstract: Despite a good haemodynamic result, many children have a mildly decreased arterial-oxygen saturation following a total cavopulmonary connection. Our study was performed to determine possible mechanisms of right-to-left shunting in these patients. We performed elective cardiac catheterization in 19 children at a mean interval of 3.6 years following a total cavopulmonary connection. The intrapulmonary right-to-left shunt, the intracardiac right-to-left shunt and the total right-to-left shunt were calculated under mechanical ventilation with 100% oxygen. The intrapulmonary right-to-left shunt was 10.8+/-3.5% of the pulmonary blood flow, and the total right-to-left shunt accounted for 18.9+/-5.2% of the systemic blood flow. The intracardiac right-to-left shunt in patients with no relevant venovenous collaterals or leaks in the atrial tunnel was calculated at 6.4+/-3.0% of the systemic blood flow, while the intracardiac right-to-left shunt in patients with relevant collaterals or leaks accounted for 13.0+/-5.9% of the systemic blood flow. Since intrapulmonary arteriovenous fistulas were not demonstrated angiographically in any of our patients, the intrapulmonary right-to-left shunt is probably due to low ratios of perfusion to ventilation in some pulmonary segments. The intracardiac right-to-left shunt was due to leaks across the interatrial baffle, collaterals between systemic and pulmonary veins, and to the coronary sinus draining to the pulmonary venous atrium.
authors.affiliation: Department of Pediatric Cardiology, University Erlangen-Nürnberg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Buheitel
authors.forename: M
authors.initials: M
authors.lastname: Hofbeck
authors.forename: U
authors.initials: U
authors.lastname: Tenbrink
authors.forename: G
authors.initials: G
authors.lastname: Leipold
authors.forename: J
authors.initials: J
authors.lastname: vd Emde
authors.forename: H
authors.initials: H
authors.lastname: Singer
mesh_terms: D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D005260:Female; D018610:Heart Bypass, Right; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D008297:Male; D010100:Oxygen / Q000097:blood; D011652:Pulmonary Circulation; D016896:Treatment Outcome
chemical_list: D010100:Oxygen