Purpose: to make computer tomography (CT) 3D reconstruction of coronary sinus (CS) and its tributaries in CRT candidates and compare it to intraprocedural occlusive coronary sinus venography.
Methods: study group included 19 patients with median age 68 (37; 79) (min; max) years. All participants had NYHA III functional class of chronic heart failure and complete left bundle branch block (LBBB) with median QRS duration 190 (141;230) ms. Ejection fraction was 28 (14; 35)%. 11 patients had ischemic heart failure, 8 - non-ischemic cardiomyopathy. Non-invasive angiography was performed using cardiac CT with contrast. 3D reconstruction and analysis of CS anatomy with tributaries was done with Amycard 01C EP LAB. Moreover, left ventricle (LV) late activation zone of LBBB was determined using this software. 3D voxel model of CS was obtained from manually segmented heart model. We estimated presence of tributaries on lateral and posterolateral LV wall as well as their length, diameter, ostium angle. The target vein was determined as closest to the late activation zone in case there were several tributaries on the wall. The occlusive venography was done using balloon catheter Attain 6215-80 cm during the implant procedure. Non-invasive and invasive images were presented in standard projections such as RAO30°, LAO30° and AP (fig.1).
Results: qualitative comparison of CS anatomy in standard projections recorded non-invasively and during implantation procedure revealed the similar results. 58% (11/19) patients had lateral and/or posterolateral vein with ostium angle more than 90 degrees. In these cases LV lead was positioned in target vein during standard procedure without special tools using Acuity Pro 9 F outer guide catheter. 1 patient had persistent left superior vena cava with CS enlargement up to 26 mm and small filiform tributaries on the lateral wall in the latest activation zone. This patient has been scheduled to epicardial LV lead placement based on non-invasive findings. 1 participant had tortuous anatomy and sharp angle in ostium of CS which was missed during CT scan and non-invasive analysis. This participant was selected for epicardial LV lead placement because an attempt to insert delivery system deep in CS was unsuccessful. 32% (6/19) patients had lateral/posterolateral vein with sharp angle or tortuous anatomy in ostial part. Endocardial LV lead placement was complex in these cases and has been done with special tools such as Acuity Pro 7 F inner guide catheter.
Conclusion: non-invasive computer angiography and intraprocedural CS venography coincided in standard projections in 95% (18/19) cases. Non-invasive imaging has significant value for left ventricular lead implantation strategy, helps to identify suitable vein in the area of interest, anatomical variability in order to choose correct electrode, special delivery systems and tools.