Pacemakers and implantable cardioverter defibrillators

Five historical innovations that have shaped modern cardiothoracic surgery

Throughout history, many innovations have contributed to the development of modern cardiothoracic surgery, improving patient outcomes and expanding the range of treatment options available to patients. This article explores five key historical innovations that have shaped modern cardiothoracic surgery: cardiopulmonary bypass, surgical pacemakers, video assisted thoracic surgery, robotic surgery and mechanical circulatory support. We will review the development, impact and significance of each innovation, highlighting their contributions to the field of cardiothoracic surgery and their ongoing relevance in contemporary and perioperative practice.

Biomedical Applications of Titanium Alloys: A Comprehensive Review

Titanium alloys have emerged as the most successful metallic material to ever be applied in the field of biomedical engineering. This comprehensive review covers the history of titanium in medicine, the properties of titanium and its alloys, the production technologies used to produce biomedical implants, and the most common uses for titanium and its alloys, ranging from orthopedic implants to dental prosthetics and cardiovascular devices. At the core of this success lies the combination of machinability, mechanical strength, biocompatibility, and corrosion resistance. This unique combination of useful traits has positioned titanium alloys as an indispensable material for biomedical engineering applications, enabling safer, more durable, and more efficient treatments for patients affected by various kinds of pathologies. This review takes an in-depth journey into the inherent properties that define titanium alloys and which of them are advantageous for biomedical use. It explores their production techniques and the fabrication methodologies that are utilized to machine them into their final shape. The biomedical applications of titanium alloys are then categorized and described in detail, focusing on which specific advantages titanium alloys are present when compared to other materials. This review not only captures the current state of the art, but also explores the future possibilities and limitations of titanium alloys applied in the biomedical field.

Implantable microfluidics: methods and applications

Implantable microfluidics involves integrating microfluidic functionalities into implantable devices, such as medical implants or bioelectronic devices, revolutionizing healthcare by enabling personalized and precise diagnostics, targeted drug delivery, and regeneration of targeted tissues or organs. The impact of implantable microfluidics depends heavily on advancements in both methods and applications. Despite significant progress in the past two decades, continuous advancements are still required in fluidic control and manipulation, device miniaturization and integration, biosafety considerations, as well as the development of various application scenarios to address a wide range of healthcare issues. In this review, we discuss advancements in implantable microfluidics, focusing on methods and applications. Regarding methods, we discuss progress made in fluid manipulation, device fabrication, and biosafety considerations in implantable microfluidics. In terms of applications, we review advancements in using implantable microfluidics for drug delivery, diagnostics, tissue engineering, and energy harvesting. The purpose of this review is to expand research ideas for the development of novel implantable microfluidic devices for various healthcare applications.

Influence and safety of electronic apex locators in patients with cardiovascular implantable electronic devices: a systematic review

The widespread use of cardiovascular implantable electronic devices has increased concerns regarding using electronic apex locators in patients with these devices. This systematic review investigated the effects and safety of using electronic apex locators in patients with cardiovascular implantable electronic devices.

METHODS

An electronic search in the Cochrane Library, PubMed (MEDLINE), ScienceDirect, and Scientific Electronic Library Online (Scielo) databases for relevant articles published between December 2000 and December 2018 was performed. The search strategy centered on terms related to electronic apex locators use during root canal treatment in patients with cardiovascular implantable electronic devices.

RESULTS

Seven studies (five in vitro and two in vivo) fulfilled the inclusion criteria for this review. It was found that electronic apex locators can be used safely in patients with cardiovascular implantable electronic devices, when general precautions are followed.

CONCLUSIONS

Although the present review suggests that electronic apex locators can be used safely in patients with implantable cardioverter defibrillators, consultation with patients' cardiologists remains advisable.

Periprocedural Considerations for Patients with Gastric Electrical Stimulators

OBJECTIVES

Gastric electrical stimulation (GES) is a technology that uses neurostimulation for the modulation of gastric activity. In clinical practice, the most commonly encountered form of GES is high frequency GES. GES devices are typically used for the treatment of refractory gastroparesis, although they have also been investigated for obesity management and the treatment of refractory gastroesophageal reflux disease. Just as many patients with chronic diseases require surgery, patients with an implanted GES device may encounter the need for periprocedural care. Therefore, the purpose of this review is to address the special needs of patients with an implanted GES device.

MATERIALS AND METHODS

A systematic computerized search of the literature was performed to consolidate existing knowledge on GES management in the periprocedural setting. Duplicate results were eliminated, and results were further narrowed based on title and abstract. All articles with possible relevance were then reviewed in full. Manufacturer information including pamphlets and websites were also reviewed.

RESULTS

A total of 1201 articles were identified for initial review, and 33 met inclusion criteria.

CONCLUSIONS

Available data suggests GES is a technology with increasing prevalence. When patients with an implanted GES device present for periprocedural care, the anesthesia staff must consider the device when planning for the procedure. Topics addressed include general anesthetic considerations, nerve localization, radiation exposure, electrocautery, diathermy, emergency external defibrillation, and MRI compatibility.

Electromagnetic interference of dental equipment with implantable cardioverter defibrillators

OBJECTIVE

Implantable cardioverter defibrillators (ICDs) are subject to electromagnetic interference (EMI). The aim of this study was to assess both the EMI of dental equipments with ICDs and related factors.

MATERIALS AND METHODS

High- and low-speed handpieces, an electric toothbrush, an implant motor and two types of ultrasonic devices were tested next to an ICD with different sensitivity settings. The ICD was immersed in a saline solution with electrical resistance of 400-800 ohms to simulate the resistance of the human body. The dental equipments were tested in both horizontal (0°) and vertical (90°) positions in relation to the components of the ICD. The tests were performed with a container containing saline solution, which was placed on a dental chair in order to assess the cumulative effect of electromagnetic fields.

RESULTS

The dental chair, high- and low-speed handpieces, electric toothbrush, implant motor and ultrasonic devices caused no EMI with the ICD, irrespective of the program set-up or positioning. No cumulative effect of electromagnetic fields was verified.

CONCLUSIONS

The results of this study suggest that the devices tested are safe for use in patients with an ICD.

Double valve replacement in a patient with implantable cardioverter defibrillator with severe left ventricular dysfunction

Recent data from landmark trials suggest that the indications for cardiac pacing and implantable cardioverter defibrillators (ICDs) are set to expand to include heart failure, sleep-disordered breathing, and possibly routine implantation in patients with myocardial infarction and poor ventricular function.[1] This will inevitably result in more patients with cardiac devices undergoing surgeries. Perioperative electromagnetic interference and their potential effects on ICDs pose considerable challenges to the anesthesiologists.[2] We present a case of a patient with automatic ICD with severe left ventricular dysfunction posted for double valve replacement.

Lack of interference between small bowel capsule endoscopy and implantable cardiac defibrillators: an 'in vivo' electrophysiological study

BACKGROUND

Capsule endoscopy is a widely performed procedure for small bowel investigation. Once swallowed by the patient, the capsule transmits images to an external recorder over a digital radiofrequency communication channel. Potential electromagnetic interferences with implantable cardiac devices have been postulated. Clinical studies on the safety of capsule endoscopy in patients with cardiac defibrillators are lacking.

OBJECTIVE

The aim of this study was to assess potential mutual electromagnetic interferences between capsule and defibrillators.

METHODS

This study used the Given M2A video capsule system. Ten different types of defibrillators were tested in a clinical setting. Before capsule ingestion, defibrillator electrical therapies were switched off. During capsule endoscopy patients were monitored with cardiac telemetry. At the end of capsule endoscopy the following defibrillator's parameters were analysed: change in device settings; inappropriate shocks; inappropriate anti-tachycardia therapy; inappropriate sensing or pacing; noise detection; device reset; programming changes; permanent electrical damages. Any technical problem related to capsule image transmission was recorded.

RESULTS

Neither defibrillator malfunction nor interference in sensing or pacing was recorded; conversely, no capsule malfunction potentially caused by defibrillators was registered.

CONCLUSION

Our results suggest that capsule endoscopy can be safely performed in patients with cardiac defibrillators.

Electromagnetic interference of endodontic equipments with cardiovascular implantable electronic device

OBJECTIVES

Assess the electromagnetic interference (EMI) of endodontic equipment with cardiovascular implantable electronic devices (CIEDs) and related factors.

METHODS

The laser device, electronic apex locators (EAL), optical microscope, endodontic rotary motors, gutta-percha heat carrier (GH), gutta-percha gun and ultrasonic device were tested next to CIEDs (Medtronic and Biotronik) with varied sensitivity settings and distances. CIEDs were immersed in a saline solution to simulate the electrical resistence of the human body. The endodontic equipment was tested in both horizontal and vertical positions in relation to the components of the CIED. The tests were performed on a dental chair in order to assess the cumulative effect of electromagnetic fields.

RESULTS

It was found no EMI with the Biotronik pacemaker. EALs caused EMI with Medtronic PM at a 2 cm distance, with the NSK(®) EAL also affecting the Medtronic defibrillator. GH caused EMI at 2 cm and 5 cm from the Medtronic defibrillator. EMI occurred when devices were horizontally positioned to the CIED. In the majority of the cases, EMI occurred when the pacemaker was set to maximum sensitivity. There was cumulative effect of electromagnetic fields between GH and dental chair.

CONCLUSIONS

EALs and GH caused EMI which ranged according to type and sensitivity setting of the CIEDs and the distance. However, no endodontic equipment caused permanent damage to the CIED. The use of GH caused a cumulative effect of electromagnetic fields. It suggests that during the treatment of patients with CIEDs, only the necessary equipments should be kept turned on.

CLINICAL RELEVANCE

Patients with CIEDs may be subject to EMI from electronic equipment used in dental offices, as they remain turned on throughout the treatment. This is the first article assessing the cumulative effect of electromagnetic fields.

Patients with pacemaker or implantable cardioverter-defibrillator

The preparation of patients with a cardiac implantable electronic device (CIED) for the perioperative period necessitates familiarity with recommendations from the American Society of Anesthesiologists and Heart Rhythm Society. Even clinicians who are not CIED experts should understand the indications for implantation, as well as the basic functions, operations, and limitations of these devices. Before any scheduled procedure, proper CIED function should be verified and a specific CIED prescription obtained. Acquiring the requisite knowledge base and developing the systems to competently manage the CIED patient ensures safe and efficient perioperative care.

Management of exposure of cardiac pacemaker systems

The erosion and exposure of pacemakers are relatively uncommon occurrences but, given the number of these devices inserted yearly, they are nevertheless occurrences that plastic surgeons are likely to encounter in practice. Although there is a general agreement that clinically infected devices are best removed, it has been established that exposed but noninfected devices can usually be managed conservatively with coverage procedures. Reports in the literature, to date, describe a number of different procedures for coverage, and these reports generally comprise small numbers of patients. This study describes 16 patients referred to a single surgeon over a 14-year period with exposure or suspected impending exposure of their cardiac pacemaker systems. Fourteen patients required surgical revision for coverage of either the generator or defunctionalized wires. Equivalent success was achieved with either subfascial or submuscular coverage in 11 patients with generators present. Three patients with exposure of defunctionalized wires achieved successful coverage with submuscular burial. There was no correlation of culture results with recurrence of exposure.

Implications of pacemakers and implantable cardioverter defibrillators in urological practice

PURPOSE

Pacemakers and implantable cardioverter defibrillators are widely used and often encountered in urology practices worldwide. Safety and performance during electrosurgery, extracorporeal shock wave lithotripsy, magnetic resonance imaging, positron emission tomography and radiotherapy are not clearly defined. We reviewed the literature on their use and implications in urological practice.

MATERIALS AND METHODS

We performed a PubMed® search and all relevant articles were studied to understand the basic functioning of these devices along with the technological advances designed to reduce electromagnetic interference.

RESULTS

A modern permanent pacemaker is comprised of a generator and leads connecting to the atrial or ventricular myocardium with sensing and pacing functions. Implantable cardioverter defibrillators respond to episodes of ventricular tachycardia and fibrillation by discharging a defibrillating current. From a device perspective, several protective mechanisms have been developed in the permanent pacemaker/implantable cardioverter defibrillator to reduce the effects of electromagnetic interference. These involve generator material changes, lead modification, and better sensing and pacing algorithms. Magnetic resonance imaging compatible pacemakers have now been developed and are approved for use in Europe. From a urologist's perspective 5 procedures require the close monitoring of permanent pacemaker/implantable cardioverter defibrillator function. 1) For electrosurgery modifications in the device and in the methods of use have been recommended. 2) For extracorporeal shock wave lithotripsy the European Association of Urology provides some guidance with regard to patients with these devices. 3) During positron emission tomography the pulse generator and the lead area should be covered with lead to protect the device. 4) Magnetic resonance imaging is contraindicated but currently trials are under way for a new pacing system for safe use in the magnetic resonance imaging environment. 5) Patients can undergo radiotherapy with standard precautions but those with an abdominal permanent pacemaker/implantable cardioverter defibrillator require careful planning. Finally, implanted devices should have a full evaluation before and after the procedure.

CONCLUSIONS

Clear guidelines are essential given the rapid advances in technology to enhance patient safety. Magnetic resonance imaging should be avoided in patients without a magnetic resonance imaging compatible device. However, patients can undergo extracorporeal shock wave lithotripsy, radiotherapy and positron emission tomography as long as the device is not in the path.

Diathermy in perioperative practice

Diathermy has revolutionised modern surgery and is an important tool for efficient and safe surgical practice. It has evolved to become the modern day scalpel, being used for cutting and coagulating tissues. This article addresses the functioning and safe use of diathermy in the perioperative setting. The various precautionary checks before surgery, which are prerequisite for safe usage, are highlighted along with the necessary safety drills during and after operation. A specific note is included about the use of electrical equipment in specialised surgeries like cardiac and laparoscopic surgery. The issues regarding the maintenance and repair of equipment are acknowledged and finally, the anticipation for a future with precise and safer cutting and coagulation devices is addressed.

Safety of electromagnetic articulography in patients with pacemakers and implantable cardioverter-defibrillators

PURPOSE

Electromagnetic articulography (EMA) uses a helmet to create alternating magnetic fields for tracking speech articulator movement. An important safety consideration is whether EMA magnetic fields interfere with the operation of speakers' pacemakers or implantable cardioverter-defibrillators (ICDs). In this investigation, individuals with pacemaker/ICD devices were exposed to EMA fields under controlled conditions while potential interference was examined.

METHOD

Twelve adults with pacemaker/ICD devices from 3 major manufacturers were assessed for device function before, during, and after exposure to magnetic fields from a Carstens AG100 EMA system. Potential interference was probed, with EMA transmitters positioned at varying distances from the implantable devices and with the EMA system set at different operating strengths.

RESULTS

No adverse affects in device operation were observed under any conditions. The only potential complication was temporary telemetry-link interference during device testing in some cases.

CONCLUSION

The results suggest that EMA technology may be safely used with patients who have pacemakers and ICDs. However, the present findings do not rule out potential interference with other pacemaker/ICD manufacturers or with different articulography systems. Precautions are suggested for testing individuals with pacemaker/ICDs under EMA conditions.

[Implantable pacemakers and defibrillators: implications for anesthesia and perioperative management]

The technological complexity of implantable devices for managing arrhythmias, specifically pacemakers and defibrillators, has increased spectacularly since their introduction a few decades ago. A growing number of patients with these devices are undergoing surgery and it is therefore essential to understand how they work and what the real associated risks are. Manuals and reference works on anesthesia may provide little information on these devices and their perioperative management. It is no longer satisfactory to place a magnet over these devices during surgery and assume that this action will protect the patient from the possible effects of electromagnetic interference. This review examines the basic principles and operation of implantable pacemakers and defibrillators, the relevant nomenclature, and the sources and effects of electromagnetic interference; the current recommendations for the perioperative management of patients fitted with these devices are also discussed.

Anaesthetic implications of arrhythmogenic right ventricular dysplasia/cardiomyopathy

Arrhythmogenic right ventricular dysplasia, also called right ventricular cardiomyopathy, is a genetically determined heart muscle disease, characterised by life-threatening ventricular arrhythmias in apparently healthy young people. The primary myocardial pathology is that the myocardium of the right ventricular free wall is replaced by fibrous or fibrofatty tissue, with scattered residual myocardial cells. Right ventricular function is abnormal and in severe cases is associated with global right ventricular dilation and overt biventricular heart failure. Although still relatively rare, arrhythmogenic right ventricular cardiomyopathy is a well recognised cause of sudden unexpected peri-operative death. In this review, we describe the basic characteristics of this disease, emphasising the diagnosis and we offer some suggestions for the anaesthetic management of these patients in the peri-operative period.

Current Perioperative Management of the Patient With a Cardiac Rhythm Management Device

The safe and effective perioperative management of the patient with a cardiac rhythm management device (ie, pacemaker and/or implantable cardioverter defibrillator) is based entirely on the avoidance of adverse outcomes, including damage to the device, the leads, or the site of lead implantation that might prevent the device from functioning as intended. An important management principle is the potential reprogramming of such a device in the perioperative period to avoid transient interruption of device function or the delivery of inappropriate electrophysiological therapy (eg, unnecessary defibrillation or pacing). Given the large numbers of patients worldwide currently implanted with these devices, the anesthesia practitioner should become electively familiar with the current technology. This article describes the current status of cardiac rhythm management devices and discusses recommended perioperative management.

Application of a clinical magnet over implantable cardioverter defibrillators: is it safe and useful?

The growing number of implantable cardioverter defibrillator (ICD) implants mean that a high number of patients carrying these devices are attended by physicians. In an attempt to simplify their management, articles have been published on the safety of applying magnets to the ICD in order to avoid the administration of shocks during surgery. However, performance of these procedures without the supervision of expert personnel can be accompanied by serious and potentially fatal complications. We report a case where the use of a clinic magnet over an ICD caused it to switch to "end of life" in the battery indicator and lose some antitachycardia therapies.

Pacemakers: some of the risks and complications you are not warned about

Pacemaker technology has advanced rapidly over the last decade. A lot of everyday interference can be regarded as transient. The media tend to cover stories of relatively insignificant transient interference incurred by pacemaker wearers while many manuals gloss over the high risks, some potentially life-threatening. These include the reliability of pacemakers and the use of monopolar diathermy which can generate electromagnetic interference, potentially causing a pacemaker to malfunction.

3D lithographically fabricated nanoliter containers for drug delivery

Lithographic patterning offers the possibility for precise structuring of drug delivery devices. The fabrication process can also facilitate the incorporation of advanced functionality for imaging, sensing, telemetry and actuation. However, a major limitation of present day lithographic fabrication is the inherent two-dimensionality of the patterning process. We review a new approach to construct three dimensional (3D) patterned containers by lithographically patterning two dimensional (2D) templates with liquefiable hinges that spontaneously fold upon heating into hollow polyhedral containers. The containers have finite encapsulation volumes, can be made small enough to pass through a hypodermic needle, and the 3D profile of the containers facilitates enhanced diffusion with the surrounding medium as compared to reservoir systems fabricated in planar substrates. We compare the features of the containers to those of present day drug delivery systems. These features include ease of manufacture, versatility in size and shape, monodisperse porosity, ability for spatial manipulation and remote triggering to release drugs on-demand, the incorporation of electronic modules, cell encapsulation, biocompatibility and stability. We also review possible applications in drug delivery and cell encapsulation therapy (CET). The results summarized in this review suggest a new strategy to enable construction of "smart", three dimensional drug delivery systems using lithography.

Cardiac risk factors for dental procedures: knowledge among dental practitioners in Wales

OBJECTIVES

To determine knowledge and educational needs of dental practitioners in Wales regarding congenital or acquired cardiac disease and the provision of antibiotic prophylaxis.

DESIGN

Self-administered postal questionnaire.

SETTINGS

Cardiff University Dental Hospital, district general hospitals (HDS), all general dental practices (GDP) and community dental service (CDS) clinics throughout Wales. Methods A questionnaire sent to 1,182 dentists in Wales in 2004-5.

RESULTS

528 questionnaires were returned (a response rate of 45%). These were analysed using one-way analysis of variance to compare summary scores between the occupation groups. Significant differences in knowledge of cardiac risk factors for infective endocarditis and for dental procedures requiring cover were observed between the occupation groups. The majority of dentists (92% GDPs, 94% CDS and 77% HDS) requested postgraduate education in cardiac risk factors and laminated flow diagrams for their surgeries as the preferred educational format.

CONCLUSION

The knowledge of Welsh dentists regarding cardiac conditions or procedures which are risk factors for paediatric and adult patients varied according to place of work. The study identified potential for under- and over-prescription of antibiotic prophylaxis within the current guidance. There was confusion as to which patient groups and cardiac conditions required prophylaxis and for which particular dental procedures. Postgraduate education detailing advances in cardiology practice is necessary for dentists.

Temporary epicardial pacing after cardiac surgery: a practical review

The first part of this two-part review discussed the indications for various types of epicardial pacing systems and an overview of the routine care of a pacemaker-dependent patient. Dual chamber temporary pulse generators now feature many of the refinements developed initially for use in permanent pacemakers. Few of these are utilised in the immediate postoperative period, often solely due to lack of familiarity with all but basic functions. The second part of the review deals with the selection of pacing modes. Troubleshooting real and apparent pacemaker malfunctions, including manual adjustment of parameters such as the AV interval, post atrial refractory period and upper rate limit, to avoid over- and undersensing, cross-talk and pacemaker-mediated tachycardia will also be addressed.