High‐Density Mapping of the Sinus Node in Humans: Role of Preferential Pathways and the Effect of Remodeling

Abstract

The functional sinus node complex demonstrates dynamic changes in activation. There are preferential pathways of conduction from sinus node to atrial myocardium. The remodeled atria demonstrate longer conduction times along preferential pathways and a restricted functional sinus node complex.

Novel Ablation Strategy for Isolating the Superior Vena Cava Using Ultra High-Resolution Mapping

“…However, the intraindividual beat-to-beat EA location was variable in the range of up to 41 mm. 20 In our maps, multicentric, or more accurately, bicentric activation, was observed in approximately 30% of cases. However, because the maps were a composite of several hundred beats obtained from contact mapping, we cannot say whether multicentric EA resulted from simultaneous activation or not.…”

Fibrosis, Electrics and Genetics

“…The site of first activation may vary from a superior to inferior position along the posterior wall of the RA and there may even be multiple simultaneous leading pacemakers. 5 Endocardial high-density mapping confirms a SAN pacemaker complex extending inferiorly along the CT 6 and construction of an anatomically detailed model of the rabbit SAN using a combination of histology, electrical mapping and immunohistochemistry supports the view of the extensive nature of the node ( Figure 1B). 7 The leading pacemaker site (site of first activation) is dynamic, a phenomenon known as pacemaker shift (Figures 1C-E).…”

“…There is a caudal shift of the leading pacemaker site within the SAN pacemaker complex, both in isolated SND 25 and in the presence of heart failure (HF), AF or atrial flutter (Figure 3). 6,26,27 The cause of SND is often couched in terms of fibrosis and degeneration. Methodological constraints of early studies led to a belief that progressive SAN fibrosis and loss of SAN cells 45 There is undoubtedly an association between stable CAD and chronic SND because both are diseases of aging.…”

Modern Electrophysiology Mapping Techniques

“…[38]. Similarly, non-contact mapping has revealed that activation of the functional sinus node complex demonstrates preferential pathways of conduction between the earliest activation point and the site from which centrifugal activation occurs to the remaining atria [39].…”