Description and evaluation of the Res-Q Arrhythmia Control Device

The Res-Q Arrhythmia Control Device (Intermedics Inc.) is one of the latest entries into the growing implantable cardioverter defibrillator (ICD) market. Dysrhythmias are classified according to their zone of detection, with a bradycardia zone, up to 3 tachycardia zones, and a fibrillation zone. Detection criterion, therapies, and redetection criterion within each zone are independently programmable, tailoring the setup to each individual's needs. In a hierarchical manner, this allows efficacy, urgency, and patient comfort to be appropriately balanced. Tachycardia therapy options include antitachycardia pacing (ATP), low-energy cardioversion, and high-energy shock, while VVI pacing provides bradycardia therapy. ATP programming is extremely flexible. Biphasic waveform and a maximum output of 700 V have yielded a high rate of successful implantation. Unique features include the multiprogrammable sensing autogain, which tracks evoked T waves during pacing, as well as the use of the pulse generator to perform implant testing. Major strengths include programming flexibility and individualized therapy for multiple dysrhythmias. The major shortcoming relates to a lack of stored electrograms. Although long-term follow-up is not yet available, the Res-Q appears to be a capable challenger to a peer group of advanced generation ICDs.