[Onset, stability and electrogram width criteria: efficacy and safety in the detection of supraventricular tachycardia in implantable cardioverter-defibrillators].

Inadequate therapies for supraventricular tachycardia (SVT) by implanted cardioverter defibrillators (ICD) are potentially arrhythmogenic and impair the patient's quality of life. Inadequate detection (ID) of SVT can be reduced by using detection enhancements like the onset- and stability criteria (O + S) or the electrogram width criterion (EGW). 103 patients (85 male, 18 female, mean age 65 +/- 9 years, mean ejection fraction 40 +/- 16%) were initially randomized to O + S active (Onset 12/89%, Stability 30 ms) or O + S inactive in the lowest detection zone. Cross-over between O + S active and O + S inactive occurred every 3 months. In 40 patients (39%) with ICD capable of EGW, this feature was programmed to passive. The number of ID was referred to 1 year of follow-up. During the follow-up period (485 +/- 226 d), 31 patients (32%) developed SVT in the lowest detection zone, 11 patients (11%) ventricular tachycardia (VT) and 14 patients (14%) both. In total, 387 SVT and 127 VT were observed. The mean number of ID was 10.7 +/- 4.8 ID/year with inactive O + S, and was significantly reduced to 1.1 +/- 0.3 ID/year when O + S were active (p < 0.0001). During the whole study period no delayed or inhibited adequate therapy for VT due to O + S was observed. During follow-up using EGW (n = 40), when O + S were inactivated, resulted in a significant reduction from 19.8 +/- 11.6 to 0.5 +/- 0.2 ID/year (p = 0.007). Even while O + S were active EGW would further reduce ID from 1.2 +/- 0.5 to 0.2 +/- 0.1 ID/year (p = 0.028). However, 2 adequate therapies of VT in 2 patients would have been suppressed if EGW had been activated. This results in a sensitivity of 98% and a specificity of 93% when O + S were inactive and respectively 95 and 79% when O + S were active. The empirical programming of O + S is therefore a safe method for the reduction of ID in patients with ICD. Using EGW leads to further reduction of ID but may lead to underdetection in individual cases.