Premium
Atrial Activation Sequence During Junctional Tachycardia Induced by Thermal Stimulation of Koch's Triangle in Canine Blood‐Perfused Atrioventricular Node Preparation
Author(s) -
IWASA ATSUSHI,
MOTOMURA SHIGERU,
SASAKI SHINGO,
DAITOKU KAZUYUKI,
HIGUMA TAKUMI,
OKUMURA KEN
Publication year - 2002
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1046/j.1460-9592.2002.00753.x
Subject(s) - tachycardia , medicine , atrioventricular node , stimulation , coronary sinus , sinoatrial node , cardiology , atrial tachycardia , bundle of his , electrocardiography , anatomy , heart rate , electrical conduction system of the heart , catheter ablation , ablation , blood pressure
IWASA, A., et al. : Atrial Activation Sequence During Junctional Tachycardia Induced by Thermal Stimulation of Koch's Triangle in Canine Blood‐Perfused Atrioventricular Node Preparation. Junctional tachycardia is observed during radiofrequency ablation of the slow pathway. The authors investigated the atrial activation sequence during junctional tachycardia induced with thermal stimulation in canine blood‐perfused atrioventricular node (AVN) preparation. The canine heart was isolated ( n = 7 ) and cross‐circulated with heparinized arterial blood of the support dog. The activation sequence in the region of Koch's triangle ( 15 × 21 mm ) was determined by recording 48 unipolar electrograms. Atrial sites anterior to the coronary sinus ostium (site AN), close to the His‐potential recording site (site N) and superior to site N (site F), were subjected to a continuous temperature rise from 38°C to 50°C with a heating probe. The temperature of the tissue adjacent to the heating site was monitored simultaneously. Junctional tachycardia at a rate of 92 ± 12 beats/min with the His potential preceding the atrial one in the His‐bundle electrogram was induced during thermal stimulation at site AN ( temperature 42.1°C ± 0.9°C ) in all seven preparations, whereas junctional tachycardia was induced during stimulation at site N in one and at site F in none. In each case, the temperature rose only at the site of stimulation. The earliest activation site during junctional tachycardia induced by site AN stimulation was at the His‐potential recording site in five preparations and the middle of Koch's triangle in the other two. After creating an obstacle between sites AN and N, atrial tachycardia at a rate of 85 ± 11 beats/min was induced during site AN stimulation. The earliest activation site during this tachycardia was site AN. Thus, junctional tachycardia induced by thermal stimulation was suggested to originate from the AN thermal stimulation site. The impulse from the stimulation site appeared to conduct via the posterior input to the compact AVN and junctional tachycardia was generated. When the posterior input was interrupted, atrial tachycardia was generated.