Comparison of a Novel, Single-Lead Atrial Sensing System With a Dual-Chamber Implantable Cardioverter-Defibrillator System in Patients Without Antibradycardia Pacing Indications

Abstract

MD; for the ADRIA InvestigatorsBackground-Supraventricular tachyarrhythmias are the main cause for inappropriate therapy by implantable cardioverterdefibrillators (ICDs). For better rhythm discrimination, an atrial electrogram is helpful and usually obtained from an additional atrial lead, even in the absence of sinus node or atrioventricular nodal disease. An Aϩ-ICD system with integrated atrial sensing rings mounted 15 to 18 cm from the tip of an ICD lead may obviate the need to implant a separate atrial lead. The aim of the study was to compare the novel Aϩ-ICD and a conventional dual-chamber (DR)-ICD. Methods and Results-Two hundred forty-nine patients with standard ICD indications but no requirement for antibradycardia pacing were randomized to receive an Aϩ-ICD (nϭ124) or a DR-ICD (nϭ125). Implantation details, need for ICD system revision, long-term sensing, documented arrhythmia episodes, and the respective rhythm discrimination during follow-up were analyzed. The implantation time was significantly shorter in the Aϩ-ICD group (67Ϯ30 vs 79Ϯ30 minutes, Pϭ0.003). Mean P-wave amplitudes were 3.5Ϯ0.8 mV (Aϩ-ICD) and 3.2Ϯ0.6 mV (DR-ICD) and remained stable during the follow-up period of 12 months. Surgical revision was necessary in 13 patients in the DR-ICD and 10 in the Aϩ-ICD group. All 593 ventricular tachyarrhythmia episodes were correctly discriminated. Sensitivity and specificity of supraventricular tachyarrhythmia discrimination were not different between the study groups. Conclusions-The novel Aϩ-ICD system can be implanted faster and is equivalent to a standard DR-ICD with regard to the detection of ventricular tachyarrhythmias and supraventricular tachyarrhythmias. It represents a useful alternative to obtain atrial sensing. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00324662.

Using Floating Atrial Electrodes to Combat the Rising Tide of Inappropriate Defibrillator Therapies

“…The authors state that this rate was chosen in order to facilitate detection of "as many SVT episodes as possible in order to compare the efficacy of the SMART detection enhancement algorithm between the 2 groups." 10 As expected, procedural times were shorter for the AϩICD group (67 versus 79 minutes; Pϭ0.003). Aside from shorter implant times, the VDD lead avoided the complication of atrial lead dislodgement, which occurred in 4% of patients in the DR-ICD arm, similar to reported rates.…”

“…The SMART tachycardia discrimination algorithm used in the Sticherling et al study 10 is proprietary and has been previously validated. 15 The SMART algorithm uses criteria related to rate, onset, and stability.…”

“…18 So, we agree with the authors' conclusion that this system "provides an attractive alternative to an additional atrial lead if one wishes to obtain an atrial electrogram in ICD patients." 10 …”

Minimizing Inappropriate or “Unnecessary” Implantable Cardioverter-Defibrillator Shocks

“…This has prompted investigation of ICDs using a single lead that have a noncontact atrial sensing bipole integrated into the ICD lead. The recently published ADRIA (Study to Verify Proper Detection of Supraventricular Tachyarrhythmia With Single-Lead Dual-Chamber Implantable Cardioverter-Defibrillators) study, however, failed to show noninferiority of such a system to traditional DC ICDs in the discrimination of SVTs and VT. 40 Furthermore, there was a high incidence of atrial undersensing and far-field R-wave sensing with this lead. Inappropriate shocks were part of a composite score, and the ability of SC and DC modes for appropriate discrimination and therapy delivery was not the primary end point evaluated.…”

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation

“…The first electrode was the Kainox A+, which revealed excellent sensing capabilities. 4 However, it was not commonly used due to electrode stiffness and large diameter (3.5 mm, 10.5 F). Further developments of this electrode lead to the creation of the Linox smart S DX lead, which has a smaller diameter (2.6 mm, 7.8 F) and demonstrates excellent implantation features and sensing capabilities.…”