The intraoperative visualisation technique during lead implantation into the cardiac conductive system: aspects of computed tomography: prospective study

Abstract

INTRODUCTION : The lead implantation into the cardiac conduction system (CCS) is the most physiological method of pacing nowadays. «The method of intraoperative visualization and control of the lead position for permanent electrocardiostimulation during implantation of the lead in the CCS» has been developed for reduce the number of non-targeted implantations. This method based on the integration into the angiograph system 3D-reconstruction of the heart converted to computed tomography (CT) in the form of a mask against the background of fluoroscopy. CT is an important stage of the intraoperative visualization technique (IVT). OBJECTIVE: The aim of the study was to adapt the protocol of CT examination of the heart with contrast to construct a partially segmented 3D-reconstruction of the heart on an angiographic complex for subsequent use during of the lead implantation in the CCS within the framework of the author’s IVT. MATERIALS AND METHODS : As part of the development of the IVT, 21 CT studies of the heart were selected from own database. The step of the gradient of the density difference of the contrasted blood is about 10 HU, the range of the difference of densitometric parameters of the «left ventricle (LV) — right ventricle (RV)» from 0 HU to 200 HU. As well as selected 11 CT studies of the heart. The step of the gradient of the difference of densitometric indicators the contrasted blood in «the RV cavity — myocardium» is about 10 HU, the range is from 0 HU to 100 HU. All CT scans are alternately loaded into the angiograph, followed by the creation of a 3D model of the heart using basic software. RESULTS: It’s necessary to exceed the degree of contrast of the LV cavity over the RV cavity by at least 80 HU to perform partial segmentation on the left and right chambers of a 3D-model of the heart in an angiographic complex that does not have a specialized segmentation module. A sufficiently large part of the left ventricular cavity (LV) disappears with a smaller gradient when the right ventricular cavity (RV) is suppressed. The minimum gradient of «the ventricular cavity — myocardium» is at least 20 HU. The boundaries of the right ventricular edge of the interventricular septum (IVS) are not visualized with a smaller contrast gradient. It’s important for determining the insertion place of the lead into the IVS. CONCLUSION : It’s necessary to exceed the contrast of the LV cavities above the RV cavity by at least 80 HU, the RV cavity above the myocardium by at least 20 HU to perform partial segmentation on the left and right chambers of a 3D-model of the heart in an angiographic complex that does not have a specialized segmentation module