Risk and benefits of temporary pacemaker electrodes in adult open-heart surgery—a systematic review

Background To assess the achieved risk and benefits of inserting temporary epicardial pacemaker electrodes after open-heart surgery for potential treatment of postoperative cardiac arrhythmias, and to investigate the extent of its use in clinical practice. Main text A systematic search was conducted in PubMed and repeated in Embase and Scopus using the PRISMA guidelines. The search identified 905 studies and resulted in 12 included studies, where the type of surgery, study design, total number of included patients, number of patients having temporary pacemaker electrodes inserted, number of patients requiring temporary pacing, primary reason for pacing, significant factors predicting temporary pacing, registered complications and study conclusion were assessed. Eight papers concluded that routine insertion of temporary pacemaker electrodes in all postoperative patients is unnecessary. One paper concluded that they should always be inserted, while three papers concluded that pacing is useful in the postoperative period, but did not recommend a frequency of which they should be inserted. Conclusions The literature suggests that the subgroup of younger otherwise healthy patients without preoperative arrhythmia having isolated coronary artery bypass grafting surgery or single valve surgery should not routinely have temporary pacemaker electrodes inserted.

Conducting Dermatological Operations in Patients Who Have Previously Undergone Cardiac Surgery

Thoracic surgical procedures and the use of cardiac devices such as pacemakers are becoming increasingly common in the population. Therefore, dermatologists may be more likely to encounter previously implanted or discarded surgical material during a dermatological operation on the chest wall. A basic understanding of the types of wires and tunneling paths used in such procedures is essential to accurately predict the presence of these wires and effectively manage any chance encounters. Dermatologists should be aware that temporary epicardial pacemaker electrodes and pacemaker electrodes often remain in the chest wall of many patients. All patients with a history of cardiac surgery should be asked about the possible presence of temporary epicardial electrodes in their body, and if such materials are found during the operation, it is necessary to immediately stop the procedure and do not undertake further manipulations with them until the material from which it is made is determined. Specialists in cardiology and cardiothoracic surgery need to document any abandoned wire in the patient's list of problems and inform the patient about the abandoned wire so that he or she can be an important source of clinical information. Trying to pull out the remaining pacemaker electrodes is a serious risk, so dermatologist surgeons should not attempt it under any circumstances. When detecting wire material, it is necessary to determine the type and location of the material before any manipulation or pulling attempts. Once it is established that this is a non-functional, abandoned wire, it is necessary to apply the correct technique for removing it, which consists in gently pulling and securing the wire at the exit point. Accurate identification of the material is required in order not to interfere with the operation of the active device and not to abandon the operation unnecessarily. The aim of the work is to consider the implementation of dermatological operations in patients who have previously undergone cardiac surgery.

Recordings of Impedance and Communication Between Defibrillator and Pacemaker Electrodes

External defibrillation involves short electric shocks of several thousand volts applied to the chest of patients suffering from heart stop. The shock coordinates disorganized muscle fibers of the heart which then can resume normal activity. Implanted pacemakers monitor the natural electrical activity of the heart via electrodes mounted permanently on the inside of the heart. If this activity is insufficient, the pacemaker stimulates the heart muscle by applying a short electrical impulse of a few volts. During the period of defibrillation, voltage differences arise simultaneously between various locations of the body preventing recordings of the heart's natural activity. In order to quantify parameters determining voltage and current in a conductive medium or in a myocardium when defibrillator and pacemaker electrodes are present simultaneously, impedances between electrodes positioned on conductive materials were recorded in laboratory set ups, and the methods were tested using a porcine heart in vitro.

Impact of Material Anisotropy on Deformation of Myocardial Tissue due to Pacemaker Electrodes

A Pacemaker electrode can penetrate the heart wall, and to design a penetration-resistent lead tip sound knowledge regarding failure of ventricular tissue is required. Numerical simulations can be particular helpful in that respect, but depend on a reliable constitutive description for ventricular tissue. In this study an anisotropic hyperelastic model for the myocardium has been implemented and compared to predictions from an isotropic description. Specifically, the response due to pushing a rigid punch into the myocardium was studied. Results between anisotropic and isotropic descriptions of the myocardium differed significantly, which justified the implementation of an anisotropic model for the myocardium.