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Pacing Parameters (pacing + parameter)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Sheathless Implantation of Permanent Coronary Sinus-LV Pacing Leads

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2006
PETER HOFFMEISTER
Background: Implantation of CS-LV pacing leads is usually accomplished through specialized sheaths with additional use of contrast venography and other steps. Direct implantation at a target pacing site could provide a simplified procedure with appropriate leads. Methods: A progressive CS-LV lead implant protocol was used, with initial attempts made to place the lead directly using only fluoroscopy and lead stylet or wire manipulation. Coronary sinus (CS) sheaths were only used later if direct lead placement failed. Results: There were 105 attempted implants with 96% (101/105) success. Leads were implanted sheathlessly in 69% (70/101) cases. Pacing parameters and final lead position did not differ significantly between implants that did or did not require sheaths for implants. Three peri-procedural complications occurred in implants where sheaths were used. In 33% (33/101) of implants, the leads were placed without the use of sheaths or contrast venography in 20 minutes or less. Conclusions: Direct placement of the CS-LV pacing lead without sheaths can be accomplished successfully in a majority of implants and in ,20 minutes in a third, without inferior pacing parameters. This may provide for shorter or less technically difficult or expensive procedures with low risk. [source]

47 Effects of retrograde gastric electrical stimulation on gastric motility and plasma hormones in dogs

NEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006
G SONG
Aims:, The aim of this study was to investigate the effect of different parameters of RGES with trains of long pulses in turning gastric slow waves into tachygastria, and evaluate the effects of RGES with the efficient trains of pulses on gastric slow waves, gastric emptying of solids and plasma concentrations of satiety-related peptides and glucose. Methods:, Seven female dogs implanted with four pairs of gastric electrodes were studied in two experiments. The first experiment included a series of sessions with different pacing parameters in the fasting state, each lasting 10 min. The second experiment included two randomized sessions (control and RGES). Gastric emptying of solid was measured by scintigraphy for a period of 4 h. Blood samples were collected at 45 and 15 min before, 30, 60 and 120 min after the meal. Plasma leptin, insulin and glucagon were measured using radioimmunoassay method. Plasma glucose was assessed with a commercially available glucometer. RGES was applied via the distal pair of electrodes (2 cm above the pylorus) with trains of pulses. RGES was initiated 30 min before the first blood sample and maintained for a period of 2.5 h. Gastric slow waves and symptomatic response were also recorded in each session. Results:, (1) RGES with pulse trains (12 trains/min) was able to turn regular gastric slow waves into tachygastria. (2) RGES with the efficient parameters (frequency: 40 Hz; pulse width: 2 ms; amplitude: 5 mA; train on-time, 2 s; off-time, 3 s) was capable of delaying gastric emptying of solids (P < 0.05). (3) Compared with the control session without RGES, the total AUC's of plasma insulin with RGES was significantly decreased in the fasting and postprandial periods (p < 0.05). However, the total area under curves (AUC's) of plasma leptin, glucagon, and glucose were not significantly affected by RGES (p > 0.05). (4) This method of GES induced no noticeable symptoms. Conclusion:, RGES with at a tachygastrial frequency decreases gastric emptying of solids and plasma insulin, but has no effects on plasma leptin, glucagons, and glucose. [source]

Right Ventricular Septal Pacing: A Comparative Study of Outflow Tract and Mid Ventricular Sites

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2010
RAPHAEL ROSSO M.D.
Background: Prolonged right ventricle (RV) apical pacing is associated with left ventricle (LV) dysfunction due to dysynchronous ventricular activation and contraction. Alternative RV pacing sites with a narrower QRS compared to RV pacing might reflect a more physiological and synchronous LV activation. The purpose of this study was to compare the QRS morphology, duration, and suitability of RV outflow tract (RVOT) septal and mid-RV septal pacing. Methods: Seventeen consecutive patients with indication for dual-chamber pacing were enrolled in the study. Two standard 58-cm active fixation leads were passed to the RV and positioned in the RVOT septum and mid-RV septum using a commercially available septal stylet (model 4140, St. Jude Medical, St. Paul, MN, USA). QRS duration, morphology, and pacing parameters were compared at the two sites. The RV lead with less-satisfactory electrical parameters was withdrawn and deployed in the right atrium. Results: Successful positioning of the pacing leads at the RVOT septum and mid-RV septum was achieved in 15 patients (88.2%). There were no significant differences in the mean stimulation threshold, R-wave sensing, and lead impedance between the two sites. The QRS duration in the RVOT septum was 151 ± 14 ms and in the mid-RV septum 145 ± 13 ms (P = 0.150). Conclusions: This prospective observational study shows that septal pacing can be reliably achieved both in the RVOT and mid-RV with active fixation leads using a specifically shaped stylet. There are no preferences in regard to acute lead performance or paced QRS duration with either position. (PACE 2010; 33:1169,1173) [source]

Successful Cervical MR Scan in a Patient Several Hours after Pacemaker Implantation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2009
DORITH GOLDSHER M.D.
Recent data showed that patients with electrical implanted devices may under certain conditions be scanned safely by magnetic resonance imaging (MRI). The device must have been in place preferably for at least 4,8 weeks [Correction added after online publication 31-Aug-2009: number of weeks has been updated.] prior to MR imaging to allow healing and pacemaker pocket formation. We report on a patient with quadriplegia and suspected epidural hematoma referred for MR scan a day after he had a pacemaker implantation. The patient was also pacemaker-dependent. After considering the risk/benefit ratio in this patient, it was decided to perform the scan. The pacemaker was reprogrammed. MRI was performed under strict monitoring. A spinal cord contusion at the level of C1,3 was diagnosed. Based on the imaging findings no invasive procedure was done. Device interrogation found no change in sensing or pacing parameters or in the pacemaker's battery. At the end of the scan, the device was reprogrammed back to the initial settings. In this population, each scan should be discussed thoroughly and the risks to benefit ratio should be considered. Given appropriate precautions, in well-experienced imaging centers, MRI may be safely performed in patients with permanent cardiac electronic implantable devices. [source]