Simultaneous epicardial-endocardial mapping of the sinus node in humans with structural heart disease: Impact of overdrive suppression on sinoatrial exits.

Ramanathan Parameswaran; Geoffrey Lee; Gwilym M Morris; Alistair Royse; John Goldblatt; Marco Larobina; Troy Watts; Chrishan J Nalliah; Geoffrey Wong; Ahmed M Al-Kaisey; Robert D Anderson; Aleksandr Voskoboinik; Hariharan Sugumar; David Chieng; Prashanthan Sanders; Peter M Kistler; Jonathan M Kalman
The 3-dimensional (3D) nature of sinoatrial node (SAN) function has not been characterized in the intact human heart.The purpose of this study was to characterize the 3D nature of SAN function in patients with structural heart disease (SHD) using simultaneous endocardial-epicardial (endo-epi) phase mapping.Simultaneous intraoperative endo-epi SAN mapping was performed during sinus rhythm at baseline (SR) and postoverdrive suppression at 600 ms (SR) and 400 ms (SR) using 2 Abbott Advisor HD Grid Mapping Catheters. Unipolar and bipolar electrograms (EGMs) were exported for phase analysis to determine (1) activation exits; (2) wavefront propagation sequence; (3) endo-epi dissociation; and (4) fractionation. Comparison of these variables was made among the 3 rhythms from an endo-epi perspective.baselineSixteen patients with SHD were included. SR activations were unicentric and predominantly exited cranially (87.5%) with endo-epi synchrony. However, with overdrive suppression, a tendency for caudal exit shift and endo-epi asynchrony was observed: SR vs SR: cranial endo 75% vs 87.5% (P = .046); cranial epi 68.8% vs 87.5% (P = 0.002); caudal endo 12.5% vs 6.2% (P = 0.215); caudal epi 25% vs 6.2% (P = .0003); and SR vs SR: cranial endo 81.3% vs 87.5% (P = 0.335); cranial epi 68.7% vs 87.5% (P = 0.0034; caudal endo 12.5% vs 6.2% (P = .148); caudal epi 31.2% vs 6.2% (P = 0.0017), consistent with multicentricity. EGM fractionation was more prevalent with overdrive suppression.baselineDuring mapping of the intact human heart, SAN demonstrated redundancy of sinoatrial exits with postoverdrive shift in sites of earliest activation and epi-endo dissociation of sinoatrial exits.
ISSN 1556-3871
Published 02 Jul 2020
DOI 10.1016/j.hrthm.2020.06.034
Type Journal Article