Multidetector cardiac tomography: a useful tool before cardiac resynchronization therapy.

Background: Left ventricular lead placement in a suitable coronary vein is a key determinant of responsiveness to cardiac resynchronization therapy (CRT). Multidetector cardiac tomography (MDCT) is a non-invasive alternative to depict cardiac venous anatomy although coronary sinus (CS) retrograde venography (RV) is the gold standard. The aim of this study was to evaluate the accuracy of MDCT to determine the presence of CS tributaries before CRT. Methods: A retrospective analysis of 41 consecutive patients eligible to CRT was performed. MDCT was assessed in all patients before CRT and RV was achieved in 39 patients. Both methods evaluated the presence of the inferior interventricular vein (IIV), posterior vein (PV) and lateral main vein (LMV). CS ostium diameter and distance between the CS ostium and right atrium (RA) lateral wall were also measured. Results: The IIV was identified in 100% of MDCT and in 43.6% of RV. In comparison to RV, the MDCT's sensitivity to identify PV and LMV was 100% for both, kappa coefficient of 0.792 (CI 95% 0.46-0.93) and 0.69 (CI 95% 0.46-0.91), respectively. There was no significant difference between ischemic and non-ischemic patients regarding the presence of PV or LMV. Median CS antero-posterior diameter was 10.3 mm (IQR 7.5-13) and supero-inferior was 14.1 mm (IQR 11.5- 17) (p < 0.01). A positive correlation (p < 0.001) between echocardiographic RA area and the distance from CS ostium to the RA lateral wall in the MDCT was observed. Conclusions: MDCT is as accurate as RV to depict CS and its tributaries (IIV, PV, LMV), and it could be useful as a non-invasive technique before CRT.