Pacemaker contact dermatitis: The effective use of a polytetrafluoroethylene sheet.

A 52-year-old man with Down's syndrome was implanted with a DDDR pacemaker for advanced atrioventricular block. He was admitted with development of skin eczema and partial exposure of the generator 1 year after reimplantation. There was no evidence of infection on laboratory data. A skin patch test was positive for the metal of the generator (purity 99.9% titanium) after 72 hours. These findings indicated pacemaker contact dermatitis. After the patient was reimplanted with a pacemaker wrapped with a polytetrafluoroethylene sheet, there has been no recurrence of the contact dermatitis during a follow-up period of 3 years.

Mapping-guided ablation of the cavotricuspid isthmus: a novel simplified approach to radiofrequency catheter ablation of isthmus-dependent atrial flutter.

BACKGROUND: Because the anatomic features of the cavotricuspid isthmus (CTI) are complex, radiofrequency (RF) energy requirements for CTI ablation may vary at each point within the CTI. Conventionally, multiple-site mapping has been required for determining CTI conduction block. OBJECTIVES: The purpose of this study was to develop a more efficacious method for ablation of isthmus-dependent atrial flutter. METHODS: Forty consecutive patients underwent CTI ablation using a CTI mapping-guided approach (20 patients) or a conventional approach (20 patients). In the CTI mapping-guided approach, an octapolar catheter was positioned on the CTI parallel to, and downstream from, the intended ablation line in order to map and ablate the breakthrough point. RESULTS: Complete CTI block was achieved in all study patients. CTI mapping of incomplete ablation lines revealed that the site with the shortest interval between double potentials did not always coincide with the conduction gap. Disappearance of a breakthrough pattern on the CTI electrograms corresponded to creation of complete CTI block. During ablation, CTI mapping exhibited pseudo-CTI block in 8% of patients in the clockwise direction and 63% of patients in the counterclockwise direction. The number and total time of RF applications were significantly lower with the CTI mapping-guided approach than with the conventional approach (7.7 +/- 3.9 applications vs 13.8 +/- 8.9 applications and 8.9 +/- 4.4 minutes vs 16.3 +/- 11.9 minutes, respectively, P <.05). In the CTI mapping-guided approach, RF applications were not required along the entire CTI in 7 patients (35%). CONCLUSION: This simplified technique was feasible for creating and determining complete CTI block, with fewer RF applications required.

Pseudotermination of atrioventricular nodal reentrant tachycardia related to isorhythmic atrioventricular dissociation.

Unusual manifestations of the mode of termination were observed in a patient with atrioventricular nodal reentrant tachycardia (AVNRT). After administration of verapamil during AVNRT, isorhythmic atrioventricular dissociation occurred without termination of the tachycardia. The sinus rate was slightly faster than that of the AVNRT, leading to the P wave preceding the QRS complex with a normal PR interval (e.g., pseudotermination). This phenomenon emphasizes the importance of continuous monitoring during an attempt to terminate AVNRT.

Characteristics of the electrical activity within the persistent left superior vena cava: comparative view with reference to the ligament of Marshall.

We sought to characterize the electrical activity within the persistent left superior vena cava (LSVC), which normally becomes the ligament of Marshall (LOM) that is known to be related to the genesis of atrial tachyarrhythmias. A 20-pole electrode catheter was used to record the entire activation sequence in the LSVC in a patient with Wolff-Parkinson-White syndrome. Electrical activity representing the musculature of the LSVC could be recorded up to a level as high as the pulmonary artery. Multiple electrical connections between the LSVC and left atrium were shown, and one of the connections exhibited unidirectional conduction block. It might be important to take into account the presence of multiple electrical connections when we consider the LOM as a target for radiofrequency catheter ablation or its role in clinical arrhythmias.