ABSENT RIGHT SUPERIOR VENA-CAVA IN VISCEROATRIAL SITUS-SOLITUS

Absence of the right superior vena cava (SVC) in visceroatrial situs s olitus is rare (0.07% to 0.13% of congenital cardiovascular malformati ons), and little is known about the type and frequency of additional h eart defects-and arrhythmias. We reviewed previous publications and pr esent 9 new cases. Based on 121 known cases, we found that this anomal y is typically characterized by: (1) persistence of the left SVC drain ing; into the right atrium by way of the coronary sinus, and (2) left- sided azygos vein draining into the left SVC. Less constant features w ere: (3) additional cardiovascular malformations (46%), and (4) rhythm abnormalities (36%) that usually appeared related to the complication s of old age. Since absence of the right SVC is clinically silent, its status should be assessed echocardiographically prior to invasive med ical or surgical procedures. This is important to avoid various manage ment difficulties during the following procedures: (1) implantation of a transvenous pacemaker, (2) placement of a pulmonary artery catheter for intraoperative or intensive care unit monitoring without fluorosc opy, (3) systemic venous cannulation for extracorporeal membrane oxyge nation, (4) systemic venous cannulation for cardiopulmonary bypass, (5 ) partial or total cavopulmonary anastomoses; and (6) orthotopic heart transplantation and endomyocardial biopsies. (C) 1997 by Excerpta Med ica Inc.