Dimensions and Angulations of The Coronary Sinus Tributaries: Implications for Left Ventricular Pacing.

Background The coronary venous system is represented by the coronary sinus (CS) and its tributaries. High variability of the coronary venous tree challenges electrocardiologists. The aim of this study was to evaluate the morphology of CS tributaries, useful and important for invasive procedures, with regards to their angles of entrance to the CS, cannulation distance and ostium diameter. Methods A total of 200 autopsied human hearts form healthy donors (22% females) were investigated. The ostia of coronary veins to the CS were identified and their diameters were measured. Distances between middle cardiac vein (MCV), posterior vein of left ventricle (PVLV) and left marginal vein (LMV) ostium and CS ostium (cannulation distance) and angles between coronary veins and CS long axis were evaluated. To simulate clinical procedures during measurements 8‐ and 7‐French catheters were used. This study has been conducted in conformance with the Basic Principles of the Declaration of Helsinki and their expansion. Results Small cardiac vein was absent in 52 examined hearts (26.0%). The MCV was present in all assessed specimens. It's mean distance to CS ostium was 5.3±3.2 mm. All MCVs opened to CS, forming with its long axis mean angle of 82.0±12.8°. The average diameter of MCV ostium was 1.8±0.5 mm. The PVLV was observed in 127 hearts (63.5%), two PVLVs was detected in 54 specimens (27.0%) and three PVLVs in 2 hearts (1.0%). In 5 cases (2.5%) a single main PVLV and small ventricular tributaries were observed. The mean distance between CS ostium and the nearest PVLV (from the CS ostium) was 19.7±9.3 mm; second order vein: 27.5±10.4 mm; third order PVLV 31.3±0.1 mm. The mean diameters of PVLVs ostia were: first: 1.2±0.5 mm; second: 1.1±0.6 mm; third: 1.1±0.2 mm. The PVLV entered to the CS at mean angle of: first: 97.0±14.0°; second: 97.9±11.4° and third vein: 117.5±3.5°. The LMV was present in 94 hearts (47.0%). It was either a tributary of CS (17 specimens) or it entered to the GCV (62 hearts). In 15 cases small ventricular tributaries of LMV were detected (7.5%). The mean distance between CS ostium and LMV was 46.0±12.0 mm. It's mean angle was 92.0±13.4° and average LMV ostium diameter was 0.9±0.5 mm. Conclusion In this research we found MCV with diameter never smaller than 0.5 mm, which makes it quite convenient for electrophysiological procedures. The PVLV was highly variable in number, unfortunately presence of more posterior veins makes it less suitable for cannulation due to smaller diameter. The LMV entering to CS would be potentially more accessible for lead implantation, but those were found only in 8.5% of hearts. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .