Pacemakers and defibrillators: anaesthetic implications

Electroconvulsive Therapy in Patients With Cardiac Implantable Electronic Devices: A Case Report and Systematic Review of Published Cases

OBJECTIVE

The aims of the study were to report the case of a 54-year-old man with recurrent depressive disorder with multiple medical comorbidities having a dual-chamber pacemaker, treated successfully with 11 sessions of electroconvulsive therapy, and to conduct a systematic review of published cases documenting the use of electroconvulsive therapy (ECT) in patients with cardiac implantable electronic devices (CIEDs) for treating major psychiatric disorders.

METHODS

We searched electronic databases (MEDLINE, PubMed, Google Scholar, Embase, Cochrane Library, PsycINFO, and Crossref) and included studies reporting on the use of electroconvulsive therapy in patients with CIEDs.

RESULTS

Thirty-five publications across 53 years (1967-2021) reported on 76 patients (including current report) who received a pooled total of 979 modified ECT sessions. The most common adverse events were premature ventricular contraction and hypertension. There have been no reports of serious adverse effects that necessitated the cessation of ECT.

CONCLUSIONS

Electroconvulsive therapy is a safe and efficacious treatment for major psychiatric disorders, and the presence of CIEDs should not delay or deter the use of ECT in these patients.

The perioperative management of small animals with previously implanted pacemakers undergoing anaesthesia

OBJECTIVE

There is little information in the veterinary literature about the perioperative management of small animal patients with previously implanted pacemakers undergoing elective or emergency non-cardiac procedures. The purpose of this article is to review the current literature with regard to human patients, with previously implanted pacemakers, undergoing general anaesthesia. Using this and the current information on pacemakers and anaesthesia in dogs and cats, we provide recommendations for small animal patients in this situation.

DATABASES USED

Google Scholar, PubMed and CAB Abstracts using and interlinking and narrowing the search terms: "dog", "cat", "small animals", "anaesthesia", "pacemaker", "perioperative", "transvenous pacing", "temporary pacing". Scientific reports and human and small animal studies from the reference lists of the retrieved papers were reviewed. In addition, related human and veterinary cardiology and anaesthesia textbooks were also included to create a narrative review of the subject.

CONCLUSIONS

The best perioperative care for these animals comes from a multidisciplinary approach involving the anaesthetist, cardiologist, surgeon and intensive care unit team. When such an approach is not feasible, the anaesthetist should be familiar with pacemaker technology and how to avoid perioperative complications such as electromagnetic interference, lead damage and reprogramming of the device. The preanaesthetic assessment should be thorough. Information regarding the indication for pacemaker placement, complications during the procedure, location, type and programming of the pacemaker should be readily available. The anaesthetic management of these veterinary patients aims to preserve cardiovascular function while avoiding hypotension, and backup pacing should be available during the perioperative period. Further prospective studies are needed to describe the best perioperative care in small animals with a previously implanted pacemaker.

Investigation into the effect of transcranial direct current stimulation on cardiac pacemakers

BACKGROUND

Studies investigating the therapeutic applications of transcranial direct current stimulation (tDCS) in the treatment of age-related neurodegenerative disease have been promising. However, exclusion criteria for these studies invariably disqualify patients implanted with internal cardiac pacemakers, citing safety concerns. Because the majority of cardiac pacemaker implantees are over 65, this criterion may limit candidacy for tDCS based research and/or treatment of age-related neurodegenerative disease.

OBJECTIVE/HYPOTHESIS

We will test the hypothesis that tDCS impacts pacemaker function. Strong electrical potentials, such as those generated by external defibrillators (∼500 V, ∼10 A), are known to occasionally damage pacemaker circuitry and software, but it seems unlikely tDCS would damage a pacemaker because it involves about 1/200th the energy (∼12 V, ∼2 mA) of an external defibrillator.

METHODS

We delivered tDCS to seven participants (ages 70-92) with bipolar non-dependent pacemakers and subsequently collected data from the internal memory of the pacemakers to assess the tDCS signal detection, as well as alterations in mode switches, impedance levels, and pacing. Subsequently, similar assessments were carried out in participants who were pacemaker-dependent (ages 89-91).

RESULTS

After a review of the recordings, it was found that tDCS had no impact on the non-dependant, as well as the dependent, pacemakers. There were zero mode switches nor any impact on impedance levels.

CONCLUSION

Results in this small series of cases found no evidence that tDCS interferes with the function of the pacemakers and suggests tDCS can be delivered to patients equipped with a cardiac pacemaker. Further studies are needed to generalize these results to other pacemakers.

Electroconvulsive Therapy in Patients with Cardiac Pacemakers

There are few contraindications to electroconvulsive therapy and it is generally well tolerated. However, electroconvulsive therapy in elderly patients with cardiac pacemakers in situ theoretically presents an increased risk of complications. We undertook a retrospective audit of all patients who received anaesthesia for electroconvulsive therapy between January 1999 and September 2005. There were ten patients who had cardiac pacemakers in situ. They underwent a total of 147 electroconvulsive therapy treatments. In 146 out of the 147 treatments, the anaesthesia proceeded uneventfully. The findings suggest that provision of anaesthesia and electroconvulsive therapy in patients with cardiac pacemakers, including rate-responsive pacemakers, is a safe undertaking, with no extra precautions being needed except for routine ECG monitoring.

Anaesthetic management of pregnant patients with cardiac implantable electronic devices: case reports and review

Heart disease is a leading cause of maternal mortality and morbidity. Pregnant women with structural, conduction or degenerative cardiac disease who require rhythm control or who are at high risk of sudden cardiac death may carry a cardiac implantable electronic device or may occasionally require the insertion of one during their pregnancy. These women are now encountered more frequently in clinical practice, and it is essential that a multidisciplinary approach, beginning from the early antenatal phase, be adopted in their counselling and management. Contemporary cardiac rhythm control devices are a constantly evolving technology with increasingly sophisticated features; anaesthetists should therefore have an adequate understanding of the principles of their operation and the special considerations for their use, in order to enable their safe management in the peripartum period. Of particular importance is the potential adverse effect of electromagnetic interference, which may cause device malfunction or damage, and the precautions required to reduce this risk. The ultimate goal in the management of this patient subgroup is to minimise the disruption to cardiovascular physiology that may occur near the time of labour and delivery and to control the factors that impact on device integrity and function. We present the ante- and peripartum management of two pregnant women with an implantable cardioverter-defibrillator, followed by a review and update of the anaesthetic management of parturients with cardiac implantable electronic devices.

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.

Pacemakers and implantable cardioverter defibrillators--general and anesthetic considerations

A pacemaking system consists of an impulse generator and lead or leads to carry the electrical impulse to the patient's heart. Pacemaker and implantable cardioverter defibrillator codes were made to describe the type of pacemaker or implantable cardioverter defibrillator implanted. Indications for pacing and implantable cardioverter defibrillator implantation were given by the American College of Cardiologists. Certain pacemakers have magnet-operated reed switches incorporated; however, magnet application can have serious adverse effects; hence, devices should be considered programmable unless known otherwise. When a device patient undergoes any procedure (with or without anesthesia), special precautions have to be observed including a focused history/physical examination, interrogation of pacemaker before and after the procedure, emergency drugs/temporary pacing and defibrillation, reprogramming of pacemaker and disabling certain pacemaker functions if required, monitoring of electrolyte and metabolic disturbance and avoiding certain drugs and equipments that can interfere with pacemaker function. If unanticipated device interactions are found, consider discontinuation of the procedure until the source of interference can be eliminated or managed and all corrective measures should be taken to ensure proper pacemaker function should be done. Post procedure, the cardiac rate and rhythm should be monitored continuously and emergency drugs and equipments should be kept ready and consultation with a cardiologist or a pacemaker-implantable cardioverter defibrillator service may be necessary.

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.

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.

Caesarean delivery in a parturient with Holt-Oram syndrome and implantable cardioverter defibrillator: anaesthetic considerations

Holt-Oram syndrome is a rare autosomal dominant disorder characterized by skeletal upper-limb dysplasias and congenital cardiac defects. Clinical manifestations of this syndrome vary, and range from sub clinical radiologic findings to overt, life-threatening disease. The author of this article reports safe and effective use of low dose sequential combined spinal and epidural anaesthesia for caesarean section in a parturient with Holt-Oram syndrome and automatic implantable cardioverter defibrillator (AICD). Concerns with regards to anaesthetic management include problems with vascular access, possible arrhythmias, the presence of an AICD, and the possibility of cardiovascular instability. The characteristics of this syndrome and anaesthetic implications are discussed.

Brief review: anesthetic implications of long QT syndrome in pregnancy

PURPOSE

To review the effects of the long QT syndrome (LQTS) in the parturient and the current anesthetic management of patients with LQTS.

SOURCE

Relevant articles were obtained from a MEDLINE search spanning the years 1980-2006 and a PubMed search spanning the years 1949-2006. Bibliographies of retrieved articles were searched for additional articles.

PRINCIPAL FINDINGS

The prevalence of LQTS in the developed world is one per 1,100 to 3,000 of the population. Clinically, LQTS is characterized by syncope, cardiac arrest and occasionally, by a history of seizures. The QT interval can also be prolonged by drugs, electrolyte imbalances, toxins and certain medical conditions. Long QT syndrome patients are at risk of torsades de pointes and ventricular fibrillation. Medical management aims to reduce dysrhythmia frequency. The LQTS is subdivided into different groups (LQT1-6) depending on the cardiac ion channel abnormality. Torsades can be precipitated by adrenergic stimuli such as stress or pain (LQT1 and 2), sudden noises (LQT2) or whilst sleeping (LQT3). Patients with LQTS require careful anesthetic management as they are at high risk of torsades perioperatively despite minimal data on the effects of anesthetic agents on the QT interval. While information on effects of LQTS in pregnancy is limited, the incidence of dysrhythmia increases postpartum. Isolated case reports of patients with LQTS women highlight several peripartum dysrhythmias.

CONCLUSION

An understanding of LQTS and the associated risk factors contributing to dysrhythmias is important for anesthesthesiologists caring for parturients with LQTS.

Fallgruben in der Magnetresonanztomographie

The constantly extending indication spectrum of magnetic resonance imaging (MRI) is a challenge for the anaesthesiologist, who is being increasingly more consulted for assistance during the examination. Due to the special technology of MRI the anaesthetic technique differs substantially from that in the operating theatre. In addition to the permanent strong magnetic field the intermittently used high frequency impulses are also a potential danger for the patient. Patients with metal implants (e.g. cardiac pacemaker) are particularly at risk. For the safe treatment of patients during MRI a special MRI compatible anaesthesia equipment is necessary. Unsuitable devices can lead to malfunctioning or to projectile effects (attracting ferromagnetic objects into the magnet) causing injury to the patients. This paper describes the MRI technology and the associated dangers for the patient as well as the characteristics of the anaesthetic techniques.

Pacemakers and implantable cardioverter defibrillators

An increasing number of patients are now treated cardiac pacemakers and implantable cardioverter defibrillators and the technology of these is constantly changing. It is vital to have a good understanding of how they function and what the real risks are. Understanding how the device should work when functioning normally, and the possible effects of electromagnetic interference, is paramount to their safe management in the peri-operative period. Knowing when a device should be disabled or reprogrammed requires careful consideration. Information from the patient's pacemaker clinic should be sought whenever possible and can be invaluable. In addition, the Medicines Healthcare products Regulatory Agency have published the first set of UK guidelines on the management of implantable devices in the presence of surgical diathermy and this will undoubtedly provide a firm foundation on which anaesthetists can base much of their practice.

Monitor-induced tachycardia in a patient with a rate-responsive pacemaker

A patient with a ventricle-paced, ventricle-sensed and inhibited, respiratory rate-responsive pacemaker presented for orthopaedic surgery. She had been operated upon recently without any adverse effects. In the recovery unit her electrocardiograph showed a paced ventricular tachycardia of about 140 beats x min(-1) without any other adverse sign or symptom. Although this tachycardia initially decreased to 70 beats x min(-1) after about 30 min, it later rose again to 140 beats x min(-1). A pacemaker technician was consulted, who suggested that there may be interference between the bioelectric impedance signals of the patient monitoring system that was being used to measure respiratory rate and the pacemaker's own measurement systems.

Splenic rupture and haemoperitoneum in a patient with non-compaction of the left ventricular myocardium

The anaesthetic and critical care management of blunt abdominal trauma in a patient previously diagnosed with non-compaction of the left ventricular myocardium (a rare autosomal dominant inherited disease) is reported. The management was influenced by the presence of an implanted automated internal defibrillator and treatment with anticoagulants because of the high frequency of severe arrhythmias and systemic embolism. The pathophysiology of ventricular non-compaction is reviewed briefly.