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Koch's Triangle (koch + triangle)
Selected AbstractsAtrial Activation Sequence During Junctional Tachycardia Induced by Thermal Stimulation of Koch's Triangle in Canine Blood-Perfused Atrioventricular Node PreparationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2002ATSUSHI IWASA 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. [source] The VA Relationship After Differential Atrial Overdrive Pacing: A Novel Tool for the Diagnosis of Atrial Tachycardia in the Electrophysiologic LaboratoryJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2007MITSUNORI MARUYAMA M.D. Introduction: Despite recent advances in clinical electrophysiology, diagnosis of atrial tachycardia (AT) originating near Koch's triangle remains challenging. We sought a novel technique for rapid and accurate diagnosis of AT in the electrophysiologic laboratory. Methods: Sixty-two supraventricular tachycardias including 18 ATs (10 ATs arising from near Koch's triangle), 32 atrioventricular nodal reentrant tachycardias (AVNRTs), and 12 orthodromic reciprocating tachycardias (ORTs) were studied. Overdrive pacing during the tachycardia from different atrial sites was performed, and the maximal difference in the postpacing VA intervals (last captured ventricular electrogram to the earliest atrial electrogram of the initial beat after pacing) among the different pacing sites was calculated (delta-VA interval). Results: The delta-VA intervals were >14 ms in all AT patients and <14 ms in all AVNRT/ORT patients, and thus, the delta-VA interval was diagnostic for AT with the sensitivity, specificity, and positive and negative predictive values all being 100%. When the diagnostic value of the delta-VA interval and conventional maneuvers were compared for differentiating AT from atypical AVNRT, both a delta-VA interval >14 ms and "atrial-atrial-ventricular" response after overdrive ventricular pacing during the tachycardia were diagnostic. However, the "atrial-atrial-ventricular" response criterion was available in only 52% of the patients because of poor ventriculoatrial conduction. Conclusions: The delta-VA interval was useful for diagnosing AT irrespective of patient conditions such as ventriculoatrial conduction. [source] Topographic Anatomy of the Inferior Pyramidal Space: Relevance to Radiofrequency Catheter AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2001DAMIÁN SÁNCHEZ-QUINTANA M.D. Inferior Pyramidal Space and Ablation.Introduction: Radiofrequency catheter ablation carried out in the vicinity of the triangle of Koch risks damaging not only the AV conduction tissues but also their arterial supply. The aim of this study was to examine the relationship of the AV nodal artery to the inferior pyramidal space, the triangle of Koch, and the right atrial endocardial surface. Methods and Results: We studied 41 heart specimens, 24 by gross dissections and 17 by histologic sections. The proximity of the AV nodal artery to the surface landmarks of the triangle of Koch was variable, but it was notable that in 75% of specimens the artery passed close to the endocardial surface of the right atrium and within 0.5 to 5 mm of the mouth of the coronary sinus. In all specimens, the mean distance of the artery to the endocardial surface was 3.5 ± 1.5 mm at the base of Koch's triangle. The location of the compact AV node and its inferior extensions varied within the landmarks of the triangle. At the mid-level of Koch's triangle, the compact node was medially situated in 82% of specimens, but it was closer to the hinge of the tricuspid valve in the remaining 18% of specimens. In 12% of specimens, the inferior parts of the node extended to the level of the mouth of the coronary sinus. Conclusion: The nodal artery runs close to the orifice of the coronary sinus, the endocardial surface of the right atrium, the middle cardiac vein, and the specialized conduction tissues in most hearts. The nodal artery and/or the AV conduction tissues can be at risk of damage when ablative procedures are carried out at the base of the triangle of Koch. [source] The Most Common Site of Success and Its Predictors in Radiofrequency Catheter Ablation of the Slow Atrioventricular Nodal Pathway in ChildrenPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2008HAW-KWEI HWANG M.D. Background:Locating ablation targets on the slow pathway in children as one would in adults may not accommodate the dimensional changes of Koch's triangle that occur with heart growth. We investigated the most common site of success and the effect of a variety of variables on the outcome of slow pathway ablation in children. Methods:A total of 116 patients (ages 4,16 years) with structurally normal hearts underwent radiofrequency ablation of either the antegrade or the retrograde slow pathway. Ablation sites were divided into eight regions (A1, A2, M1, M2, P1, P2, CS1, and CS2) at the septal tricuspid annulus. Results:Ablation was successful in 112 (97%) children. The most common successful ablation sites were at the P1 region. The less the patient weighed, the more posteriorly the successful site was located (P = 0.023, OR 0.970, 95% CI 0.946,0.996), and the more likely the slow pathway was eliminated rather than modified: median weight was 46.7 kg (range, 14.5,94.3 kg) in the eliminated group and 56.5 kg (range, 20,82.6 kg) in the modified group (P = 0.021, OR 1.039, 95% CI 1.006,1.073). Conclusions:The most common site of success for slow pathway ablation in children is at the P1 region of the tricuspid annulus. The successful sites in lighter children are more posteriorly located. Weight is also a predictor of whether the slow pathway is eliminated or only modified. [source] Atrial Activation Sequence During Junctional Tachycardia Induced by Thermal Stimulation of Koch's Triangle in Canine Blood-Perfused Atrioventricular Node PreparationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2002ATSUSHI IWASA 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. [source] | ||||||||||