Can-SVC electrogram configuration increased atrioventricular dissociation detection in ventricular tachycardia compared to Can-RV coil configuration (61.9% vs 9.5%; OR 15.4; 95% CI 2.8-84.7; P=0.0009).
Cohort (n=140)
Does Can-SVC electrogram configuration improve P-wave detection and discrimination between VT and SVT compared to Can-RV coil configuration in patients with single-chamber ICDs?
Optimizing EGM configuration to Can-SVC significantly improves P-wave recognition and discrimination between VT and SVT in single-chamber ICDs.
Effect estimate: OR 15.4 (95% CI 2.8 to 84.7)
Absolute Event Rate: 61.9% vs 9.5%
p-value: p=0.0009
AIMS: Differentiation between supraventricular tachycardia (SVT) and ventricular tachycardia (VT) remains a substantial clinical challenge in patients with single-chamber implantable cardioverter-defibrillators (ICDs) due to absence of visible P waves. Innovative optimization of intrathoracic electrogram (EGM) configuration will facilitate P-wave detection and rhythm differentiation during tachycardia. METHODS AND RESULTS: Innovative optimization of EGM configuration was originally performed to improve patient care. In this retrospective cohort study, we examined our database for records of 140 consecutive patients undergoing single-chamber ICD implantation. During the follow-ups of 61 included patients with optimized EGM configuration, 27 patients were identified to have VT and/or SVT. EGMs in the Can (generator) to superior vena cava (Can-SVC) configuration were compared with those conventionally from the Can to right ventricular coil (Can-RV coil) source in the same patients. In Can-SVC EGMs, the ratio of P/QRS amplitude was 14-fold higher (0.57 ± 0.08 vs. 0.04 ± 0.00, P < 0.001) compared with those in Can-RV coil EGMs during sinus rhythm. With Can-SVC configuration, the odds of atrioventricular dissociation detection in patients with VT was increased 15-fold (61.9% vs. 9.5% with Can-RV coil; odds ratio, 15.4; 95% confidence interval, 2.8 to 84.7; P = 0.0009). In patients with SVT, P-waves or retrograde P-waves were markedly more identifiable in Can-SVC configuration compared with Can-RV coil (odds ratio, 40; 95% confidence interval, 3.6 to 447.1; P = 0.0010). CONCLUSION: P-wave recognition by optimizing EGM configuration provides a novel diagnostic tool for differentiation between VT and SVT in single-chamber ICDs. A potential discrimination algorithm would provide a cost-effective approach to improving the qualitative outcomes.
Xiong et al. (2013) conducted a cohort in Ventricular and supraventricular tachycardia in single-chamber ICDs (n=140). Can to superior vena cava (Can-SVC) electrogram configuration vs. Can to right ventricular coil (Can-RV coil) electrogram configuration was evaluated on Atrioventricular dissociation detection in patients with ventricular tachycardia (OR 15.4, 95% CI 2.8 to 84.7, p=0.0009). Can-SVC electrogram configuration increased atrioventricular dissociation detection in ventricular tachycardia compared to Can-RV coil configuration (61.9% vs 9.5%; OR 15.4; 95% CI 2.8-84.7; P=0.0009).