Variations and angulation of the coronary sinus tributaries: Implications for left ventricular pacing

BACKGROUND: Variations of the coronary sinus tributaries might result in difficulties in left ventricle electrode insertion during cardiac resynchronizing therapy. Morphometric features of tributaries, especially angulation of the coronary sinus tributaries, are crucial for coronary sinus procedures. METHODS: This study was carried out on 200 formaldehyde-fixed human hearts (22.0% females, mean age of 48.7 ± 15.6 years). RESULTS: The inferolateral aspect of the left ventricle was accessible from the coronary venous tree in 77.0% (in 35% from one, 29% from two, and 13.0% from three tributaries). The middle cardiac vein was present in all cases, with a diameter of 1.8 ± 0.5 mm, cannulation distance of 5.3 ± 3.2 mm, and angle of 82.0 ± 12.8°. The inferolateral vein of the left ventricle varied greatly in number: single in 63.5%, multiple in 30.5%. The ostium diameter for a single vein was 1.3 ± 0.5 mm, cannulation distance was 21.1 ± 9.8 mm, and the angle was 98.1 ± 13.5°. The left marginal vein was present in 39.5% with an ostium diameter of 0.9 ± 0.5 mm, cannulation distance of 46.0 ± 12.0 mm, and angle of 92.0 ± 13.4°. Finally, the oblique vein of the left atrium was present in 71.0% with a diameter of 1.3 ± 0.8 mm, cannulation distance of 27.2 ± 9.4 mm, and angle of 136.8 ± 16.6°. CONCLUSIONS: This study shows the clinically relevant morphometric characteristic of coronary sinus tributaries. The middle cardiac vein is the most constant among coronary veins. However, it is usually not suitable for left ventricular pacing. The inferolateral vein of the left ventricle is highly variable in number, but its morphology makes it a suitable target for left ventricular lead placement.