The Relationship Between Right Atrial Appendage And Adjacent Anatomical Structure

Objective: The relationship between right atrial appendage and adjacent anatomical structure such as the tracheal bifurcation, the spine, the diaphragm and the right side of the heart was observed by angiography of the right atrial appendage in order to provide the imaging reference of the atrial pacemaker lead implantation.Methods: 28 inpatient referred to radiofrequency catheter ablation(RFCA) due to paroxysmal supraventricular tachycardia were selected from the Department of Cardiology, The Second Hospital of Hebei Medical University. Before RFCA, we punctured the subclavian vein, implanted the sheath, sent the pigtail catheter to the boundary between the superior vena cava and the right atrium and injected 40ml of the contrast agent (10ml/s). We took the anteroposterior and the right oblique imaging of the right atrial appendage and observed the size, shape and the relationship between the right atrial appendage and adjacent anatomical structure such as the tracheal bifurcation, the spine, the diaphragm and the right side of the heart.Results: We observed 28 cases in which 26 ones took anteroposterior and right oblique imaging and 2 patients took anteroposterior imaging only. The results showed that all the right atrial appendages were triangular shape and most of them were on the lower right of the tracheal bifurcation (accounting for 85.17%). In the anteroposterior view, the appendicular size was 0.85±0.16 vertebral heights. The measurement of the highest and the lowest point of RAA to the tracheal bifurcation averaged 1.33±0.40 and 2.18±0.35 vertebral heights and the lowest point to the right side of the diaphragm when end-expiratory averaged 1.20±0.57 vertebral heights. The distance between the right side of the RAA and the right side of the heart is 0.67±0.17 vertebral heights. In the right oblique view, the appendicular size was 1.20±0.23 vertebral heights. The measurement of the lowest point to the right side of the diaphragm when end-expiratory averaged 0.81±0.51 vertebral heights.Conclusion: All the RAA were triangular shape and most of them were on the lower right of the tracheal bifurcation. Using X-ray anatomical features of the RAA and tracheal bifurcation can locate the position of the RAA more accurate, which is helpful to be safe and efficient performance of atrial pacemaker lead implantation.