Excerpts from Electrophysiology Sessions at the European Society of Cardiology Congress 2002 - Berlin

The current scope of dual chamber ICD was discussed. It seems that 50% of the implants in US and 30% in Europe consist of a dual chamber device. Factors which influence the selection of a dual-chamber device include: 1) presence of an anti-bradycardia pacing indication, 2) need to discriminate supraventricular (SVT) from ventricular tachycardia (VT), 3) prevention and therapy of SVT and 4) presence of heart failure. Algorithms from various manufacturers discriminate SVT from VT with a very high sensitivity, but the specificity varies from 70-100%, thus not a dramatic improvement over the single-chamber ICDs. A German study that compared singleversus dual-chamber ICD did not show a clear benefit with respect to inappropriate therapy. In conclusion, dual-chamber ICDs are definitely useful when class I pacemaker indication is concomitantly present, are possibly useful in the presence of slow VTs, intermittent SVTs, presence of heart failure NYHA III-IV and are definitely not indicated in the presence of chronic atrial fibrillation (AF). ICD functions have now expanded to: 1) good monitoring, 2) bradycardia support, 3) VT prevention and therapy, 4) ventricular fibrillation termination, 5) AF algorithms and 6) resynchronization. There was a plea that electrophysiologists should do device programming by themselves and not leave it to the company representative. It is true that device programming consumes a lot of office-time (20-25 minutes) and therefore devices should be simplified. This is also in the interest of cost reduction. The incidence of ICD lead dislocation (atrial) or fracture (in the costo-clavicular region) is around 4.5%. Coaxial leads are at increased risk. There was no difference in the incidence of lead dysfunction with respect to singleor dual-chamber device. Pacing parameters can easily detect lead malfunction and DFT testing is usually not indicated. Inappropriate shock as a result of lead malfunction occurs in about 40% of cases, while failure to defibrillate in 3%. Other problems include oversensing, undersensing and increase in pacing threshold. Indications and techniques of extraction of a malfunctioning lead are not widely established and information is derived from small studies. The longer the lead is in-situ the larger the chance that excimer laser will be required for extraction. Open-chest surgery is rarely used, except in cases where a lot of thrombus is present all over the lead. Understanding the effects of concomitant anti-arrhythmic drug (AAD) therapy in patients with ICD is important. AADs are frequently used when the ICD is implanted for VT and less frequently used when cardiac arrest or syncope is the indication. In the AVID study, 18% of the patients in the ICD-arm required AADs, in 2/3rds of the cases because of frequent shocks.