INTRODUCTION: The aim of this paper is to first monitor the changes in the capture threshold of endovascularly placed leads for left ventricle pacing, second to compare the pacing configurations, and third to verify the effect of Steroid elution for endovascular leads. SAMPLE AND METHOD: The study included 202 consecutive single centre patients implanted with the QuartetTM lead (St. Jude Medical). The capture threshold and related lead parameters were tested during implantation, on the day of the patient's discharge, and 3, 9, and 15 months after implantation. The electrical energy corresponding to the threshold values for inducing ventricular contraction was recorded for subgroups of patients with bipolar and pseudo-unipolar pacing vectors and electrodes equipped with and without a slow-eluting steroids. The best setting for the resynchronization effect was generally chosen. Capture threshold was taken as a selection criterion only if there were multiple options with (expected) similar resynchronization effect. RESULTS AND DISCUSSION: The measurements showed that the ratio of threshold energies of UNI vs. BI was 5× higher (p < 0.001) at implantation. At the end of the follow-up, it dropped to 2.6 (p = 0.012). The steroid effect in BI vectors was caused by a double capture threshold in the NSE group compared to the SE group (p < 0.001), increased by approximately 2.5 times (p < 0.001). The study concludes that after a larger initial increase in the capture threshold, the leads showed a gradual increase in the entire set. As a result, the bipolar threshold energies increase, and the pseudo-unipolar energies decrease. Since bipolar vectors require a significantly lower pacing energy, battery life of the implanted device would improve. When evaluating the steroid elution of bipolar vectors, we observe a significant positive effect of a gradual increase of the threshold energy.

• Publikační typ
• časopisecké články MeSH

OBJECTIVES: The ASD2 (Acute Extravascular Defibrillation, Pacing, and Electrogram) study evaluated the ability to adequately sense, pace, and defibrillate patients with a novel implantable cardioverter-defibrillator (ICD) lead implanted in the substernal space. BACKGROUND: Subcutaneous ICDs are an alternative to a transvenous defibrillator system when transvenous implantation is not possible or desired. An alternative extravascular system placing a lead under the sternum has the potential to reduce defibrillation energy and the ability to deliver pacing therapies. METHODS: An investigational lead was inserted into the substernal space via a minimally invasive subxiphoid access, and a cutaneous defibrillation patch or subcutaneous active can emulator was placed on the left mid-axillary line. Pacing thresholds and extracardiac stimulation were evaluated. Up to 2 episodes of ventricular fibrillation were induced to test defibrillation efficacy. RESULTS: The substernal lead was implanted in 79 patients, with a median implantation time of 12.0 ± 9.0 min. Ventricular pacing was successful in at least 1 vector in 76 of 78 patients (97.4%), and 72 of 78 (92.3%) patients had capture in ≥1 vector with no extracardiac stimulation. A 30-J shock successfully terminated 104 of 128 episodes (81.3%) of ventricular fibrillation in 69 patients. There were 7 adverse events in 6 patients causally (n = 5) or possibly (n = 2) related to the ASD2 procedure. CONCLUSIONS: The ASD2 study demonstrated the ability to pace, sense, and defibrillate using a lead designed specifically for the substernal space.

• MeSH
• defibrilátory implantabilní * škodlivé účinky   statistika a číselné údaje   MeSH
• elektrokardiografie MeSH
• implantace protézy škodlivé účinky   metody   mortalita   statistika a číselné údaje   MeSH
• kardiostimulace umělá * škodlivé účinky   statistika a číselné údaje   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mediastinum chirurgie   MeSH
• prospektivní studie MeSH
• senioři MeSH
• srdeční arytmie terapie   MeSH
• sternum chirurgie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinická studie MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH