论文部分内容阅读
AIM To describe our experience with shock testing for the evaluation of patients with Riata? leads.METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation(VF) induction and in 5 cases a R-wave-synchronized shock(> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients(80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients(20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance(< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF.CONCLUSION In Riata? leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing.
Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam. during shock testing: In 8 cases of VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externally-targeted receptors showed sudden drop of high-voltage impedance (<10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF.CONCLUSION In Riata® leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing.