Pulmonary venous baffle obstruction in a Senning surgery verified by 4D-flow MRI. (QF_TH_025)

Description of Clinical Presentation: 32-year-old man with a history of transposition of the great arteries corrected with Senning surgery (1994) and left atrial embolectomy with increased venous return (1995). Regular medication with enalapril and bisoprolol. In follow-up by outpatient clinic for congenital heart disease. Clinically with NYHA functional class I and palpitations. On physical examination with systolic murmur in aortic focus II/VI. Cardiac magnetic resonance was requested, with findings of flow acceleration at the site of flow redirection from the pulmonary veins to the posterior portion of the right atrium, muscular-type interventricular communication, signs of pulmonary hypertension and mild left ventricular systolic dysfunction. A 2D flow sequence was performed complemented with a 4D flow sequence, with spectacular images where the convergence of flows in the area of obstruction is visualized, with flow acceleration in the region of the baffle anastomosis with the pulmonary veins.

Diagnostic Techniques and Their Most Important Findings: Cardiac magnetic resonance (06/25/2024):
1. Late postoperative status of Senning surgery with flow acceleration at the site of flow redirection from the pulmonary veins to the posterior portion of the right atrium, diameters of 7x11mm.
Redirection of both vena cavae to the left atrium. The interatrial septum with displacement to the left, with displacement of the superior vena cava, without generating a significant gradient.
2. Dilated and hypertrophic right ventricle (systemic), with mild systolic dysfunction. RVEF 55%.
3. Left ventricle with decreased volumes and mild systolic dysfunction. LVEF 49%.
4. High muscular interventricular communication of 2x4mm with flow from the RV to the LV.
5. Diffuse fibrosis of the right ventricle.
6. Mild aortic insufficiency.
7. Dilatation of the pulmonary artery, D-shaped morphology of the left ventricle, as indirect signs of pulmonary hypertension.

Learning Points from this Case: The present case of congenital heart disease corrected with the Senning technique or atrial switch is rare today, due to its replacement by the Jatene technique or arterial switch. Combining it with a modern technique such as the new 4D flow sequence helps to assess turbulent flows in any part of the acquired data volume. In this case, it allows us to quantify the degree of obstruction, flow direction, and point of greatest flow acceleration that defines the narrowness or stenosis of the pulmonary venous baffle, which is useful for therapeutic purposes for planning prior to correction by intervention or surgery.