ACE angiotensin converting enzyme BAL bronchoalveolar lavage CRT cardiac resynchronization therapy CT computed tomography 18 F-FDG fluorine-18 fluorodeoxyglucose 67 Ga gallium-67 HRCT high resolution computed tomography ICD implantable cardioverter defibrillator MRI magnetic resonance imaging PET positron emission tomography sIL-2R soluble interleukin 2 recepter SPECT single photon emission computed tomography JCS GUIDELINES

This study demonstrates that P1 and P2 are critical potentials in a circuit of verapamil-sensitive ILVT and suggests the presence of a macroreentry circuit involving the normal Purkinje system and the abnormal Purkinje tissue with decremental property and verapamil-sensitivity.

There may be an entity of adenosine-sensitive atrial tachycardia probably due to focal reentry within the AV node or its transitional tissues without involvement of the AV nodal pathways. This tachycardia can be ablated without disturbing AV nodal conduction from the right atrial septum.

NOGAMI A et al.(5) View the monitor during imaging During imaging, the heart rate must be continuously monitored using a pulse oximeter or an ECG monitor. (6) Prepare for unexpected situations It should be ensured that the room is equipped with an electrical defibrillator to be used in an emergency, if necessary. A hospital manual for handling unexpected situations should be established. In addition, it should be kept in mind that the threshold and lead resistance need to be re-measured after imaging and the mode needs to be returned to the original setting.Recommendations are shown in Table 6. Electrophysiology StudiesThe clinical significance of induced arrhythmia depends on the underlying heart disease, type of arrhythmia, and induction protocol. Electrophysiology studies are considered less useful in patients with frequent premature ventricular contraction (PVCs) without structural heart disease.

Background-The superior vena cava (SVC) is one of the sources of ectopies that can initiate atrial fibrillation (AF). We investigated by radiofrequency ablation the electrophysiological characteristics of the junction of the right atrium (RA) and the SVC and the feasibility of electrical disconnection of the SVC from the RA. Methods and Results-Sixteen patients with paroxysmal AF after pulmonary vein isolation underwent electroanatomic mapping at the RA-SVC junction during sinus rhythm. Mapping showed sharp potentials (SVC potentials) inside the SVC. Activation spread from the earliest SVC potential (breakthrough) to the rest of the SVC. SVC potentials were found over a large amount of the circumference, suggesting widespread muscle coverage of the SVC. Breakthroughs from the RA to SVC were located anteriorly, laterally, posteriorly, and septally in 3, 4, 10, and 6 patients, respectively. The number of breakthroughs was 1.4Ϯ0.5 per patient. Radiofrequency energy was applied with the end point of electrical disconnection. All breakthroughs were eliminated with 3.1Ϯ1.7 applications per breakthrough without complications. Conclusions-SVC potentials can be recorded inside the SVC. There are specific breakthroughs from the RA to the SVC that can be identified by electroanatomic mapping. The electrical disconnection of the SVC from the RA is feasible.