The Thebesian valve and coronary sinus in cardiac magnetic resonance.

Purpose: There is no complex research exploring usefulness of cardiac magnetic resonance in the evaluation of the coronary sinus including Thebesian valve, which can be useful before selected electrophysiology procedures.
Methods: One hundred twenty-two patients aged 49.2 ± 17.2 (42 women) were included in the study; 4 of them were excluded. A steady-state free-precession (SSFP) sequence was the basis of the visualization and analysis of the coronary sinus as well as Thebesian valve. In selected cases, dedicated coronary sinus sequences were created. All data were evaluated by experienced cardiac magnetic resonance investigators.
Results: We were able to visualize the coronary sinus by using basic SSFP sequence in all patients, however in four cases in suboptimal quality. Average length of the coronary sinus was 39.73 ± 16.9 mm, average diameter was 9.81 ± 9.3 mm, and average angle of the entrance of the coronary sinus into the right atrium was 111.37 ± 13.8°. The Thebesian valve as the gate of the coronary sinus was found in 56 cases (45.9%). In 21 patients (17.2% of all), the valve was porous or almost totally covered the coronary sinus ostium, which can potentially create problems during CS cannulation.
Conclusions: In most of the cases, it is possible to visualize and measure the coronary sinus using cardiac magnetic resonance with SSFP sequence. In selected cases, it is necessary to perform additional dedicated short sequences. Thebesian valve was visualized in almost 50% of patients.