Coronary sinus anatomy by computerized tomography, overlaid on live fluoroscopy can be successfully used to guide left ventricular lead implantation: a feasibility study

Abstract

This study aims to optimize coronary sinus (CS) computerized tomography (CT) imaging and evaluate its utility for preprocedural planning and intraoperative guidance by overlay of 3D reconstructed CS images on live fluoroscopy. Optimal CS lead placement for cardiac resynchronization therapy (CRT) remains challenging. Preprocedural knowledge of CS anatomy can significantly affect procedural outcome. Optimal CS imaging protocols by CT have not been well defined. Seventeen consecutive CRT recipients underwent contrast-enhanced functional cardiac CT on a 64-slice scanner. The CS target branch closest to the most dyssynchronous LV segment was identified. 3D volume rendered CS images were superimposed onto live fluoroscopy via EP Navigator (Philips Healthcare, Best, The Netherlands) to guide CS cannulation and lead placement. The imaging protocol was optimized. CT images were successfully reconstructed and overlaid on live fluoroscopy in 16/17 patients. The overlay facilitated CS cannulation and lead placement into a predefined target branch. Excellent correlation between CT and angiographic CS anatomy was noted. By using the overlaid 3D CS as a road map, average total fluoroscopy time (14.56 ± 4.22 min) was significantly shorter when compared to historical controls. Total radiation exposure was significantly higher in the CT-guided group. Images obtained using double bolus injection and gated acquisition at 40 % of the cardiac cycle contained the most anatomical detail of the CS. Overlay of 3D CS anatomy defined by preprocedural cardiac CT is feasible. It allows planning of CRT implantation and live guidance of CS lead placement into a predefined target branch. Limiting the CT imaging to 40 % of the cardiac cycle phase provides optimal CS images and reduces radiation exposure. This approach may result in shorter procedural time and more optimal CS lead positioning. However, the concept remains to be confirmed by future studies.