Late complications following permanent pacemaker implantation

The objective of the work was to determine prospectively the rate of late complications (6, 12 months) following first implantation of a permanent pacemaker or generator replacement. To illustrate our pathology using 3 case reports with particular problems concerning the diagnosis and treatment options. We studied 126 consecutive patients with definite indications for permanent pacemaker implantation, included between 2006 and 2009. Generator replacement was required in 12 patients because of pulse generator electrical failure. In all cases a W I pacemaker was used. Implantation of the lead-catheter used right/left subclavian vein (108 cases vs. 18 cases) access. We realized a clinical follow-up (local pocket integrity, signs/symptoms for ipsilateral superior limb deep venous thrombosis or pulmonary thromboembolism-TEP) combined with biologic (D-dimers, fibrinogen, platelets), microbiologic (wound secretion, hemocultures) and imaging methods. Imaging follow-up protocol used venous ultrasound, ipsilateral superior limb phlebography, perfusion lung scintigram, transtoracic and transesophageal echocardiography. The overall rate of late complications was 23.8% in our study. There were infectious, thromboembolic complications and pacemaker syndrome signs/symptoms. Local pocket-related infection (pocket erosion/necrosis) with Staphylococcus aureus/epidermidis wad found in 7.14% of cases; in two cases Enterobacter/ Staphylococcus aureus septicemia complicated local infection. Infective endocarditis complicated evolution in one case (vegetation on the stimulation catheter). Late infectious complications rate was significantly lower after first implantation of the permanent pacemaker comparing generator replacement (1.4% vs. 6.5%) and also in the subgroup with prophylactic antibiotherapy (0.6% vs. 3.1%). Pacing electrode thrombosis was defined by ultrasound in 10 patients (12.6%) and by phlebography in 19.04%; echocardiography detected one case of thrombosis in right atrium and manifest TEP complicated evolution. In 2 cases there were clinical signs for superior limb deep venous thrombosis. Perfusion lung scintigram revealed high /intermediate probability for TEP in 5 patients, respectively 2 patients. In 3.17% of cases both types of complications were present. Pacemaker syndrome was manifest through mild symptoms/signs in 2 cases. Our data are comparable with literature concerning the rate of late infectious and thromboembolic complications. Pacing electrode thrombosis is frequently asymptomatic and underestimated in clinical terms. For this reason, the decision for anticoagulation is better individualized. Even conducted in rigorous asepsis conditions invasive technique is better followed by antibiotheraphy. The low incidence of pacemaker syndrome is in relation with follow-up period

New 99mTc - silica nanoparticles radiotracer biodistribution studied through scintigraphy

Aim of the study: Silica nanoparticles (SNP) are a new and versatile tool for targeting drug delivery. Our aim was to investigate biodistribution of a new SNP derivate in guinea pigs, in order to identify the possible uses as a drug carrier. Materials: SNP were prepared at the Institute o f Chemistry and Bioanalytics, University o f Applied Sciences Northwestern Switzerland, Muttenz, Switzerland. One 124 nm size SNP derivate was used: AA124 - SNP carrying OH groups on the surface. Methods: The procedure of 99mTc - SNP coupling was an in-house preparation performed as follows: 1- first of all, SNP were suspended in EtOH (5mg/ml) and sonicated for 15 or 20 min for better disper­sion. 2- to this suspension, 200MBq/lml of Na99mTc04 solution was added and the suspension was stirred gently. 3- an excess of NaBH4 reducing agent was added quickly to the suspension and stirred for minimum 1 hour. Scintigraphic study design: Groups of 4 animals were intravenously administered with 37MBq/kg/ animal 99mTc-coupled AA124 SNP. Control groups received 37MBq/kg animal 99mTc. A dual head Siemens gamma camera with high resolution parallel collimators was used. The image acquisitions protocol started with a dynamic image acquisition for 60 seconds (1 image/sec), followed by a dynamic image acquisition for 4 minutes (1 image/min) and static planar images (256x256 Matrix, Zoom 2) every 15 minutes for a duration of 2h. The animals were sacrificed after 120 min and different organs were extracted entirely and submited to gamma camera. Results: Following the i.v. administration, AA124 SNP did not penetrate the blood brain barrier. SNP were present in all the organs investigated except the brain, with different target/non target indexes, that were graphically represented for each of them. Conclusion: These step results represent a promising support for the idea of using the AA124 as container for modular drug delivery system with promising future in therapeutics

The antinociceptive role of magnesium after intracerebroventricular administration

Aim of the study: The present study is trying to identify experimental arguments for a magnesium role in central pain modulation following an intracerebroventricular (icv) administration. Materials and methods: Healthy adult male Wistar rats, initially weighing 350- 450 g, were used.The rats were maintained in polyethylene cages with food and water ad libitum, in a laboratory with controlled ambient temperature (21 ± 2°C) and under a 12h light-dark cycle. Groups of 7 rats were treated with magnesium (Mg) chloride,600 nmol Mg/ rat in 10 pL of saline. Stoelting stereotaxic equipment was used for icv administration, in previously ether-anesthetized animals. The controled group received an equal volume of saline. Hot plate and tail clip test was performed before 15, 30, 45, 60, 75 and 90 minutes after the administration of substances. Results: Our results show that intracerebroventricular administration of magnesium chloride has an analgesic effect for the hot plate and tail clip test. The maximum effect was observed after 75 minutes in tail clip and 90 minutes in hot plate. Discussions: While the implication of Mg as a divalent cation has been studied before in relation to pain modulation, this is the first study to look at its effects on nociception after icv administration. As magnesium blocks the N-methyl-D-aspartate (NMDA) receptor and its associated ion channels, it can prevent central sensitization caused by peripheral nociceptive stimulation. However magnesium ion can block Ca influx and at the same time can noncompetitively antagonize NMDA receptor channels Conclusions: Magnesium has an antinociceptive effect following icv administration. However, the slow onset of the analgesic effect observed in our experiments may involve a different mechanism or site of action than cited in the literature

Hypertrophic cardiomyopathy : the edge-to-edge secures the correction of the systolic anterior motion

Objectives: Although septal myectomy is the technique of choice for hypertrophic cardiomyopathy, the surgical management of concomitant mitral valve lesions is controversial. Various complex surgeries have been proposed to address mitral valve lesions. We propose a simple option using an edge-to-edge mitral valve repair through the aortic valve in addition to the septal myectomy. Methods: We performed an observational analysis of our prospectively collected database. The clinical follow-up was done by telephone contact with each patient. The echocardiographic follow-up was performed in our Department of Cardiology or by the referring cardiologist. Results: Between January 2009 and March 2016, we operated 22 symptomatic patients (mean age 48.5 years, males 59%). The mean interventricular septum diameter and resting intraventricular gradient were 25.8 mm and 75.4 mmHg, respectively. The systolic anterior motion was present in every patient. The mean mitral regurgitation grade was 2.4. There were no in-hospital deaths. Two (9%) patients required a pacemaker. After a mean follow-up of 26.3 months, the mean New York Heart Association functional class decreased from 2.5 to 1.2 (P < 0.001). The echocardiographic follow-up showed a sustained significant reduction of the septal thickness (P < 0.001), resting intraventricular gradient (P < 0.001), presence of systolic anterior motion (P < 0.001) and grade of mitral regurgitation (P = 0.002). Conclusions:Septal myectomy remains the gold standard of any surgery for hypertrophic cardiomyopathy owing to its good clinical and echocardiographic results. The edge-to-edge mitral valve repair is an additional simple option to avoid the systolic anterior motion and effectively reduce the grade of mitral regurgitation