Propagation of the sinus impulse into the Koch triangle and localization, timing, and origin of the multicomponent potentials recorded in this area.

BACKGROUND: The presence of a conduction block at the level of the Koch triangle (KT) and the origin of the multicomponent potentials inside this area are controversial issues. We investigated the propagation of the sinus impulse into the KT and the characteristics of multicomponent potentials recorded in that area in patients with and without atrioventricular nodal reentrant tachycardia (AVNRT). METHODS AND RESULTS: Thirty-two patients (16 with AVNRT, 16 without AVNRT) underwent a sinus rhythm electroanatomic mapping of the right atrium (RA). Conduction velocities in the RA and in the KT were evaluated quantitatively on activation maps and qualitatively on isochronal and propagation maps. The presence, location, and timing of different types of multicomponent potentials were evaluated. A mean of 149±44 points were sampled in the RA, whereas a mean of 79±21 points were collected inside the KT. Propagation block at the level of crista terminalis was not found in any patient, whereas slow conduction inside the KT was found in all (median conduction velocity, 122 cm/s [110 to 135 cm/s] outside KT versus 60 cm/s [48 to 75 cm/s] inside KT; P<0.0001). Jackman potentials were identified inside KT in almost all the patients and were invariably found on the line of collision between the wavefronts activating the KT in opposite directions. CONCLUSIONS: No conduction block was detected inside the KT in patients with and without AVNRT. Conduction slowing was demonstrated during propagation of the sinus impulse inside the KT. The genesis of the Jackman potential may be related to the collision of the wavefronts activating KT in opposite directions.

Pain perception during esophageal warming due to radiofrequency catheter ablation in the left atrium.

PURPOSE: We investigated the relationship among esophageal warming, pain perception, and the site of radiofrequency (RF) delivery in the left atrium (LA) during the course of catheter ablation of atrial fibrillation. Such a procedure in awake patients is often linked to the development of visceral pain and esophageal warming. As a consequence, potentially dangerous complications have been described. METHODS: Twenty patients undergoing RF ablation in the LA were studied. An esophageal probe (EP) capable of measuring endoesophageal temperature (ET) was positioned before starting the procedure. The relative position of the EP and the tip of the ablator were evaluated through fluoroscopy imaging before starting each RF delivery, during which the highest value of the temperature was collected. After RF withdrawal, the patients were asked to define the intensity of the experienced pain by using a score index ranging from 0 (no pain) to 4 (pain requiring immediate RF interruption). RESULTS: The mean ET value during ablation was 39.59 +/- 4.71 degrees C. The EP proximity to the ablator's tip showed a high correlation with the development of the highest ET values (Spearman's rank correlation coefficient r = 0.49, confidence interval (CI) 0.55-0.41). Moreover, the highest values of pain intensity were reported when the RF was delivered to the atrial zones close to the EP projection (r = 0.50, CI 0.55-0.42) and when the highest ET levels were reached (r = 0.38, CI 0.30-0.45). CONCLUSIONS: Pain perception in LA ablation is significantly related to esophageal warming and is higher when the RF is delivered near the esophagus. It seems advisable to perform ET monitoring in sedated patients to avoid short- and long-term jeopardizing of the esophageal wall.

Feasibility and safety of a simplified draping method for pacing procedures.

AIMS: Traditional draping for pacing procedures is time-consuming. We evaluated prospectively the safety of a simplified method using a single adhesive drape intended for use in cardiac catheterization. METHODS AND RESULTS: A single disposable adhesive drape was used in each of 250 consecutive pacing procedures by the same operator including 200 device implants and 50 revision procedures. We compared the results with those of 114 procedures performed in the same cardiac catheterization laboratory by three other operators using traditional draping methods for most cases. In the study group, no wound or pacemaker pocket infection, device erosion, or endocarditis was observed within the first 6 months after the procedure (0%, 95% CI 0-1.2%). One suspected infection occurred at 10 months (0.4%, 95% CI 0.1-2.2%). In the control group, there were two cases of early infection or suspected infection (2 of 114 procedures, 1.8%, 95% CI 0.27-6.1%), four cases of confirmed or suspected infection more than 6 months after the procedure giving an overall infection rate (6 of 114, 5.3%, 95% CI 2.1-11.0%) significantly higher than in the study group (P = 0.014, Fisher's exact test). CONCLUSION: A simplified draping method involving a single adhesive fenestrated drape can be used for pacemaker or ICD implantation or revision procedures without an excessively elevated risk of infective complications.