MORPHOLOGICAL CHARACTERISTICS OF RIGHT ATRIUM AND INTERATRIAL BUNDLE: CLINICAL SIGNIFICANCE

Objective - to study the morphometric characteristics of the right atrium (RA) and the interatrial (Bachmann) bundle (IAB) of the of the human heart in adults, with the purpose of installation of endocardial electrodes. Material and methods . Heart samples from 84 males and females of mature and old age who died from noncardiac pathology were obtained at autopsy and were examined using cardiometric methods, corrosion casting and plastination techniques. Results. Average IAB thickness was 5.1±0.7 mm, and average width - 15.3±3.1 mm. RA inferior-superior size was equal to 49.3±2.6 mm, transversal size - to 40.6±2.5 mm. The distance from the lateral margin of the ostium of the superior vena cava (SVC) to the top of the RA appendage (58.8±4.7 mm) was larger than the distance from SVC ostium to the IAB region (25.1±2.8 mm). The distance from the IAB to the compact part of the atrioventricular node (AVN) was, on the average, 17.9 mm shorter than the distance from the RA appendage to the AVN. Conclusion. During cardiac stimulation from IAB region, electric impulse will reach AVN quicker than that from the RA appendage, while implantation of an atrial lead into the IAB region is preferable from anatomical and electrophysiological points. It is shown that for positioning of a lead into IAB region, the stylet with a curvature of smaller diameter is required.

right atrium, interatrial (Bachmann) bundle, morphometric parameters, cardiac pacing