Cardiac Computed Tomography to Guide the Selection of Better Display Angle of Cardiac Right Ventricular Pacing Electrode in Radiography.

Abstract

Traditional radiography angles do not adequately reveal the shape and position of the right ventricular pacing electrode. This study aimed to explore better radiography angles with the help of cardiac computed tomography (CT). We analyzed the cardiac CT images of consecutive outpatients from 2018 to 2019. The right anterior oblique (RAO) 30° and the left anterior oblique (LAO) 40° were found to sufficiently display the shape and position of the right ventricular pacing electrode. A total of 214 consecutive outpatients were enrolled, whose average age was 55.0 ± 13.0 years, and 151 were male (70.6%). Through analyzing the cardiac CT images, the α angle (33.7° ± 6.1) and the γ angle (38.8° ± 8.0) were determined. Furthermore, we verified these angles in 48 patients after pacemaker implantation. The results showed that the ratio of the length of right ventricular electrode using the RAO α angle (≈30°) to the posterior-anterior position (PA position) was 1.099 ± 0.157 vs. 1.053 ± 0.182 (the ratio using the traditional RAO 45°) (P < 0.001). We observed that the relationship between the right ventricular active electrode and the ventricular septum was better identified using the LAO γ angle (≈40°) than the traditional 60° angle. With the help of cardiac CT, we found that RAO 30° could better show the shape and length of the right ventricular pacing electrode, and LAO 40° could better show the positional relationship between the pacing electrode and the ventricular septum.