Adenosine-Sensitive Focal Reentrant Atrial Tachycardia Originating From the Mitral Annulus-Aorta Junction

Adenosine-sensitive reentrant atrial tachycardia (AT) has been recognized to originate from the confined area of either the right or left atiroventricular nodal regions. We describe a case with adenosine-sensitive focal AT which was successfully ablated at the uncommon focus located at the mitral annulus-aorta junction. The mode of AT initiation during the atrial extrastimulus suggested as the mechanism tachycardia reentry; AT was terminated by a bolus of 2 mg of adenosine 5’-triphosphate. These electrophysiological features are possibly associated with a substrate involved in the mitral annulus-aorta junction with node-like properties that is responsive to adenosine

Novel Technique to Facilitate Defibrillator Lead Implantation via Cephalic Vein Cutdown by Means of a Reference Catheter and a Specially Designed Long Sheath

The cephalic vein is recommended as the access route for an implantable cardioverter defibrillator lead to avoid complications associated with subclavian vein puncture; however, cephalic vein cutdown is not necessarily preferred, mainly because of procedural complexity. To facilitate cephalic vein cutdown, we have devised the following method. An 8 Fr catheter is placed in the cephalic vein over a guidewire inserted percutaneously from the left peripheral cephalic vein. The catheter, which is palpable beneath the skin prior to incision, indicates the location of the cephalic vein, facilitating its isolation. A specially designed 9 Fr tear-away sheath-dilator unit is used to place leads. With its long-tapered and curved tip, the unit is easy to insert, even when the cephalic vein is stenotic or tortuous. The 30-cm-long sheath reaches the right atrium, and thus the lead is advanced directly to the right atrium without risk of vascular injury. This technique may be feasible in the majority of patients and can even be used by inexperienced implanters

Restoring the Recurrent Extrusion of the Subcutaneously Implanted Defibrillator by Means of Subpectoral Replacement: The Benefits of Subpectoral Implantation in the Current ICD Era

A 72-year-old man with a thin build had an ICD system with a generator implanted at left prepectoral space. The generator was exposed through thin overlying skin at 11 months following surgery. Although it was undermined with the adjacent skin, it was exposed again 6 months later. The generator was replaced in the ipsilateral subpectoral space. Since then, no signs of recurrence have been observed for the subsequent 12 months, with the patient pleased with its cosmetic appearance. This case illustrates the benefits of subpectoral implantation in the current ICD era in which subcutaneous implantation is common

Paradoxical undersensing of atrial electrograms during atrial fibrillation due to repeated activation of the quiet timer blanking interval: Case report and review of the literature

This report describes a case of paradoxical atrial undersensing by a dual-chamber pacemaker during paroxysmal atrial fibrillation. Undersensing of 5.6 mV atrial signals at a programmed sensitivity of 0.5 mV returned to normal sensing by decreasing atrial sensitivity to 1.0 mV. This uncommon phenomenon can be explained by a repeated activation of the quiet timer blanking interval. Knowledge of this phenomenon is important in the current pacemaker management to improve the accuracy of the diagnostic feature for atrial tachyarrhythmia burden and to avoid unnecessary lead revisions