Abstract 1974: Pre-Electrophysiology Catheterization Recognition of Venous Baffle Problems in Young Adults Post-Mustard Repair of Transposition of the Great Arteries
Background: Following Mustard repair of D-Transposition of the Great Arteries (dTGA), patients (pts) often require electrophysiology procedures (EP) (ablations, pacemakers) for arrhythmia management. Since unrecognized venous baffle problems (VBP) (obstruction, leaks) can complicate and impair EP, effective identification of VBP prior to EP is necessary. The purpose of the study was to determine the efficacy of clinical findings and transthoracic 2-D/Doppler echocardiography (ECHO) to identify VBP prior to EP.
Methods: History, clinical findings and ECHO reports among pts with repaired d-TGA referred for EP at our center between 1995–2008 were reviewed for identification of any VBP. Data was compared with hemodynamics and venograms during EP. The difference in the proportion of pts recognized to have VBP by ECHO/clinical findings prior to was compared with those detected only during EP using non-parametric Fisher’s Exact Chi-square. Significance was p<0.05.
Results: A total of 43 pts (M/F=27/16, median 22.5 yrs) were referred for EP. All had pre-EP ECHO and clinical evaluations. None had symptoms or clinical evidence of VBP. ECHO showed VBP in 10 (23%). During EP, VBP were detected in 22 (51%) with significant narrowing (2–10mm, mean 6), pressure changes (4 to 21mmHg, mean 5) or leaks. Venograms showed deferential azygous vein flow in all pts with obstructed atrial baffle. Baffle stenting was required in 17 pts (40%) and in 1 pt (2%) an occluder for leak was implanted before the EP could be accomplished. In spite of pre-EP ECHO/clinical evaluations, significant VBP requiring intervention were found (23% predicted vs. 51% actual, p = 0.007).
Conclusion: There is a need to recognize that transthoracic ECHO and clinical findings may be ineffective to detect the high incidence of VBP in pts with d-TGA following Mustard operation referred for EP. The atrial baffle is inherently difficult to image by ECHO especially with an enlarged azygous vein in close proximetry. In addition, the azygous vein decompresses obstructive superior vena caval-baffle flow patterns removing typical clinical findings associated with venous obstruction. Failure to recognize VBP may interfere with and/or prevent EP and require additional scheduling for vascular intervention.