Noninvasive visualization of the cardiac venous system using multislice computed tomography.

Objectives: We sought to evaluate the value of multislice computed tomography (MSCT) to depict the cardiac venous anatomy.
Background: During cardiac resynchronisation therapy (CRT), left ventricular (LV) pacing is established by a pacemaker lead in a tributary of the coronary sinus (CS). Knowledge of the CS anatomy and variations may facilitate the implantation of LV leads.
Methods: The MSCT scans of 38 patients (34 men; age 60 +/- 12 years) were studied. Anatomical variants were divided in three groups, dependent on the continuity of the cardiac venous system at the crux cordis. The CS ostium and distances between the main tributaries were measured.
Results: The most frequently observed variant had a separate insertion of the CS and the small cardiac vein in the right atrium (24 patients [63%]). In 11 patients (29%), there was continuity of the anterior and posterior venous system at the crux cordis. In three patients (8%), the posterior interventricular vein (PIV) did not connect to the CS. The mean distance from the PIV to the posterior vein of the left ventricle (PVLV) was 42.4 +/- 18.1 mm, from the PVLV to the left marginal vein (LMV) 39.9 +/- 15.6 mm, and from the LMV to the anterior interventricular vein 45.4 +/- 15.3 mm. The diameter of the CS ostium was 12.6 +/- 3.6 mm in anteroposterior and 15.5 +/- 4.5 mm in the superoinferior direction (p < 0.01).
Conclusions: The anatomy of the CS and its tributaries can be evaluated using MSCT. As substantial variation in anatomy was observed, pre-implantation knowledge of the venous anatomy may help to decide whether transvenous LV lead placement for CRT is feasible.