title: Insights from preclinical ultra high-density electroanatomical sinus node mapping.
abstract: OBJECTIVE
  Although sinus node modification by catheter ablation is an established therapy for the treatment of inappropriate sinus tachycardia, there is incomplete understanding of sinus node anatomy and function but also limited electroanatomical mapping data. Recently, an automatic, ultra high-resolution mapping system has been presented to accurately and quickly identify right atrial (RA) geometry and activation patterns but detailed assessment of sinus node activation has not been performed which was one aim of this study. Preclinical experiences are compared with previous sinus node mapping studies in animals and humans, and potential clinical implications for catheter ablation are discussed.
  
  
  RESULTS
  In anaesthetized and ventilated 14 pigs, 30 endocardial and 2 eipcardial RA maps were generated using the Rhythmia™ mapping system without complications and earliest activation sites (EAS) and sinus break-out (SBO) were determined. At baseline, EAS and SBO were located anterior to the middle (n = 6) or lower third (n = 8) of the crista terminalis exhibiting a unicentric activation pattern in all cases. Conduction pathways were directed anterior, posterior, superior, or inferior with substantial inter-individual variation in direction, pathway distance, and conduction time. Orciprenaline, propranolol, or amiodarone shifted endocardial activation with considerable variation between animals with inconsistent patterns. Multicentric activation was found in one case after orciprenaline infusion. Sequential endocardial and epicardial high-density mapping of the RA was performed in two animals and showed a high congruence of the sinus node activation in the endo- and the epicardial map.
  
  
  CONCLUSIONS
  Ultra high-density mapping allows fast, simple, and very detailed assessment of sinus node activation. Future studies are clearly needed to evaluate novel mapping and ablation strategies for an improved understanding of sinus node disease and better outcomes.
authors.affiliation: Department of Electrophysiology, Heart Center, Leipzig, Strümpellstr. 39, Leipzig 04289, Germany rhythmo@med.uni-leipzig.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bollmann
authors.affiliation: Department of Electrophysiology, Heart Center, Leipzig, Strümpellstr. 39, Leipzig 04289, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hilbert
authors.affiliation: Department of Electrophysiology, Heart Center, Leipzig, Strümpellstr. 39, Leipzig 04289, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: John
authors.affiliation: Department of Electrophysiology, Heart Center, Leipzig, Strümpellstr. 39, Leipzig 04289, Germany.
authors.forename: Jedrzej
authors.initials: J
authors.lastname: Kosiuk
authors.affiliation: Department of Electrophysiology, Heart Center, Leipzig, Strümpellstr. 39, Leipzig 04289, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hindricks
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000638:Amiodarone / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D016280:Atrial Function, Right; D022062:Electrophysiologic Techniques, Cardiac; D056149:Epicardial Mapping / Q000379:methods*; D006325:Heart Atria / Q000187:drug effects; D009921:Metaproterenol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012849:Sinoatrial Node / Q000187:drug effects / Q000502:physiology*; D013552:Swine
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D009921:Metaproterenol; D011433:Propranolol; D000638:Amiodarone
keywords: Cardiac mapping; Catheter ablation; Sinus node