Transcutaneous Cardiac Pacing Research Articles

Prehospital transcutaneous cardiac pacing in the United States: treatment epidemiology, predictors of treatment failure, and associated outcomes

ABSTRACT OBJECTIVES Transcutaneous cardiac pacing (TCP) is a potentially lifesaving therapy for patients who present in the prehospital setting with bradycardia that is causing hemodynamic compromise. Our objective was to examine the outcomes of patients who received prehospital TCP and identify predictors of TCP failure. METHODS We utilized the 2018-2021 ESO Data Collaborative public use research datasets for this study. All patients without a documented TCP attempt were excluded. Mortality was derived from hospital disposition data. TCP failure was defined as initiation of CPR following the first TCP attempt among patients who did not receive CPR prior to the first TCP attempt. Multivariable logistic regression models using age and sex as covariables were used to explore the association between prehospital vital signs and TCP failure. RESULTS During the study period, 13,270 patients received transcutaneous pacing and 2,560 of these patients had outcome data available. Overall, the mortality rate following TCP was 63.4%. Among patients who did not receive CPR prior to the first TCP attempt (n = 7,930), TCP failure (progression to cardiac arrest) occurred 20.4% of the time. Factors associated with TCP failure included increased body weight (>100 vs. 60-100 kg, aOR: 1.33 (1.15, 1.55)), a pre-pacing non-bradycardic heart rate (>50 vs. <40 bpm, aOR: 2.87 (2.39, 3.44)), and pre-TCP hypoxia (<80% vs. >90% SpO2, aOR: 6.01 (4.96, 7.29)). CONCLUSIONS Patients who undergo prehospital TCP are at high risk of mortality. Progression to cardiac arrest is common and associated with factors including increased weight, a non-bradycardic initial heart rate and pre-TCP hypoxia.

Anteroposterior pacer pad position is better than anterolateral for transcutaneous cardiac pacing

IntroductionTranscutaneous cardiac pacing (TCP) is a lifesaving procedure for patients with certain types of unstable bradycardia. We aimed to assess the difference in the pacing thresholds between the anteroposterior (AP) and anterolateral (AL) pacer pad positions. The second aim was to characterize the severity of chest wall muscle contractions during TCP. MethodsIn this prospective crossover trial, we enrolled patients presenting to the electrophysiology laboratory for elective cardioversion. After successful cardioversion, sedated participants were sequentially paced in both positions. The study procedure concluded after successful capture or inability to achieve capture by 140 mA (the pacer’s maximum output) in both positions. Pacing thresholds were compared between positions, using a student’s paired t-test, assigning a value of 141 mA to any trials with non-capture. ResultsForty-one patients were screened; 20 were enrolled in the study. Seven participants were excluded from the paired analysis (three were prevented from pacing in the second position at the anesthesiologist’s discretion, and 4 did not capture in either position). The study population consisted of 14 men and 6 women with a median age of 65 years. The mean pacing threshold was 33 mA lower (P = 0.001, 95% CI 20–45) in the AP (93 mA) versus the AL (126 mA) position. The median contraction severity score was 3 in the AL position versus 4 in the AP position (P = 0.005). ConclusionsPlacing pacer pads in the AP position requires less energy to capture. Major resuscitation guidelines may favor the AP position for TCP.ClinicalTrials.gov Identifier: NCT03898050 https://clinicaltrials.gov/ct2/show/NCT03898050.

374EMF The Ideal Transcutaneous Pacer Pad Position Study

Transcutaneous cardiac pacing is a lifesaving procedure for patients with certain types of unstable bradycardia. The American Heart Association (AHA) guidelines for the management of unstable bradycardia recommend initiating transcutaneous pacing in patients unresponsive to atropine while addressing the primary cause of the bradycardia. Current major resuscitation guidelines do not address which pacer pad position to use. The aim of this study was to assess the difference in the pacing thresholds between the anteroposterior (AP) and anterolateral (AL) pacer pad positions.

Effective methods to enhance medical students’ cardioversion and transcutaneous cardiac pacing skills retention - a prospective controlled study

BackgroundGuideline-based therapy of cardiac arrhythmias is important for many physicians from the beginning of their training. Practical training of the required skills to treat cardiac arrhythmias is useful for acquiring these skills but does not seem sufficient for skill retention. The aim of this study was to compare different retention methods for skills required to treat cardiac arrhythmias with respect to the performance of these skills in an assessment.MethodsSeventy-one final-year medical students participated in a newly designed workshop to train synchronized cardioversion (SC) and transcutaneous cardiac pacing (TCP) skills in 2020. All participants completed an objective structured clinical examination (OSCE 1) one week after the training. Afterwards, the participants were stratified and randomized into three groups. Nine weeks later, one group received a standard operating procedure (SOP) for the skills, one group participated in a second workshop (SW), and one group received no further intervention (control). Ten weeks after the first training, all groups participated in OSCE 2.ResultsThe average score of all students in OSCE 1 was 15.6 ± 0.8 points with no significant differences between the three groups. Students in the control group reached a significantly (p < 0.001) lower score in OSCE 2 (-2.0 points, CI: [-2.9;-1.1]) than in OSCE 1. Students in the SOP-group achieved on average the same result in OSCE 2 as in OSCE 1 (0 points, CI: [-0.63;+0.63]). Students who completed a second skills training (SW-group) scored not significantly higher in OSCE 2 compared to OSCE 1 (+0.4 points, CI: [-0.29;+1.12]). The OSCE 2 scores in groups SOP and SW were neither significantly different nor statistically equivalent.ConclusionsPartial loss of SC and TCP skills acquired in a workshop can be prevented after 10 weeks by reading an SOP as well as by a second workshop one week before the second assessment. Refreshing practical skills with an SOP could provide an effective and inexpensive method for skills retention compared to repeating a training. Further studies need to show whether this effect also exists for other skills and how frequently an SOP should be re-read for appropriate long-term retention of complex skills.

The electrocardiogram of ventricular capture during transcutaneous cardiac pacing

BackgroundTranscutaneous cardiac pacing (TCP) is deeply entwined with the problem of assessing ventricular capture on the electrocardiogram (ECG). We sought clarification of ventricular capture during TCP. MethodsWe studied one hundred and ten patients (75 ± 12 years) with bradycardia who underwent pacemaker or implantable cardioverter-defibrillator implantation. The cohort was stratified by structural heart disease (SHD) status and presence of narrow or wide QRS during spontaneous heart rhythm. We compared 12-lead ECG data at baseline (48 ± 7 beats/min) with those of TCP as well as of transvenous pacing (TVP) at a similar increased heart rate (76 ± 9 beats/min) to ensure constant ventricular capture. The QT interval was corrected for heart rate (QTc) using Bazett's method as well as by the Hodge's and Rautaharju's formulae depending on the presence of narrow or wide QRS at baseline. Electromechanical coupling was assessed by noninvasive arterial pressure measurement. ResultsTCP (median 80 mA) produced a QRS pattern resembling left bundle branch block. Overall, both TCP and TVP induced significant QRS and QTc prolongations when compared with baseline measures (p < 0.001). TCP created narrower QRS than TVP in those patients with SHD and narrow QRS (p < 0.006). There was no significant QTc duration difference between TCP and TVP. Mean arterial pressure underwent similar significant decrease following either TCP or TVP over baseline (p < 0.001), without difference between the two pacing approaches in any patient group. ConclusionTCP is associated with similar ECG and hemodynamic responses to those of TVP, regardless of the presence of SHD.

P017: Impact of the use of a checklist for transcutaneous cardiac pacing on competency of junior residents undergoing an advanced cardiac life support course

Introduction: Transcutaneous cardiac pacing (TCP) is recommended for the treatment of symptomatic bradycardia, a life-threatening condition. Although TCP is taught in ACLS (advanced cardiac life support) courses, it is a difficult skill to master for junior residents. The main objective of this study is to measure the impact of having access to a checklist on successful TCP implementation. Our hypothesis was that the availability of a CL would improve performance of junior residents in the management of symptomatic bradycardia by facilitating TCP. Methods: We conducted a prospective, randomized, single-site study. First-year residents entering postgraduate programs and taking a mandatory ACLS course were enrolled. Students had didactic sessions on the management of symptomatic bradycardia followed by hands-on teaching on a low-fidelity manikin (ALS® simulator, Laerdal) using a CL conceived for this project as a teaching tool. Study participants were then assessed with a simulation scenario requiring TCP. Participants were randomly assigned to groups with and without CL accessibility. Performances were graded on six critical tasks. The primary outcome was the successful use of TCP, defined as having completed all tasks. Participants then completed a post-test questionnaire. Sample size estimation was based on a previous project (Ranger et al., 2018). Accepting an alpha error of 0.05 and a power of 80%, 45 participants in each group would permit the detection of 26.5% in performance gain. Results: Of 250 residents completing the ACLS course in 2017, 85 voluntary participants were randomized to a control group (no CL available during testing, n = 42) or an experimental group (CL available during testing, n = 43). Six participants in the experimental group adequately used TCP compared to five participants in the control group (p = 0.81, chi-squared test). Out of the 43 participants who had access to the CL, only 2 (5%) used it. Reasons why the CL was infrequently used were stated as the following: 24 participants (56%) mentioned not realizing it was available, 8 (19%) considered it was of little to no utility and 5 (19%) forgot a CL existed. Conclusion: Availability of a checklist previously used during simulation teaching did not increase junior residents’ capacity to correctly apply TCP. Non-recognition of CL availability and decreased perceived need for it were the main reasons for marginal use. Our results suggest that there are many limiting factors to CL effectiveness.

High-energy external defibrillation and transcutaneous pacing during MRI: feasibility and safety

BackgroundRapid application of external defibrillation, a crucial first-line therapy for ventricular fibrillation and cardiac arrest, is currently unavailable in the setting of magnetic resonance imaging (MRI), raising concerns about patient safety during MRI tests and MRI-guided procedures, particularly in patients with cardiovascular diseases. The objective of this study was to examine the feasibility and safety of defibrillation/pacing for the entire range of clinically useful shock energies inside the MRI bore and during scans, using defibrillation/pacing outside the magnet as a control.MethodsExperiments were conducted using a commercial defibrillator (LIFEPAK 20, Physio-Control, Redmond, Washington, USA) with a custom high-voltage, twisted-pair cable with two mounted resonant floating radiofrequency traps to reduce emission from the defibrillator and the MRI scanner. A total of 18 high-energy (200-360 J) defibrillation experiments were conducted in six swine on a 1.5 T MRI scanner outside the magnet bore, inside the bore, and during scanning, using adult and pediatric defibrillation pads. Defibrillation was followed by cardiac pacing (with capture) in a subset of two animals. Monitored signals included: high-fidelity temperature (0.01 °C, 10 samples/sec) under the pads and 12-lead electrocardiogram (ECG) using an MRI-compatible ECG system.ResultsDefibrillation/pacing was successful in all experiments. Temperature was higher during defibrillation inside the bore and during scanning compared with outside the bore, but the differences were small (ΔT: 0.5 and 0.7 °C, p = 0.01 and 0.04, respectively). During scans, temperature after defibrillation tended to be higher for pediatric vs. adult pads (p = 0.08). MR-image quality (signal-to-noise ratio) decreased by ~ 10% when the defibrillator was turned on.ConclusionsOur study demonstrates the feasibility and safety of in-bore defibrillation for the full range of defibrillation energies used in clinical practice, as well as of transcutaneous cardiac pacing inside the MRI bore. Methods for Improving MR-image quality in the presence of a working defibrillator require further study.

Transcutaneous cardiac pacing competency among junior residents undergoing an ACLS course: impact of a modified high fidelity manikin

BackgroundTranscutaneous cardiac pacing (TCP) is recommended to treat unstable bradycardia. Simulation might improve familiarity with this low-frequency procedure. Current mannequins fail to reproduce key features of TCP, limiting their usefulness. The objective of this study was to measure the impact of a modified high-fidelity mannequin on the ability of junior residents to achieve six critical tasks for successful TCP.MethodsFirst-year residents from various postgraduate programs taking an advanced cardiovascular life support (ACLS) course were enrolled two consecutive years (2015 and 2016). Both cohorts received the same standardized course content. An ALS simulator® mannequin was used to demonstrate and practice TCP during the bradycardia workshop of the first cohort (control cohort, 2015) and a modified high-fidelity mannequin that reproduces key features of TCP was used for the second cohort (intervention cohort, 2016). Participants were tested after training with a simulation scenario requiring TCP. Performances were graded based on six critical tasks. The primary outcome was the successful use of TCP, defined as having completed all tasks.ResultsEighteen participants in the intervention cohort completed all tasks during the simulation scenario compared to none in the control cohort (36 vs 0%, p < 0.001). Participants in the intervention cohort were more likely to recognize when pacing was inefficient (86 vs 12%), obtain ventricular capture (48 vs 2%), and check for a pulse rate to confirm capture (48 vs 0%).ConclusionsTCP is a difficult skill to master for junior residents. Training using a modified high-fidelity mannequin significantly improved their ability to establish TCP during a simulation scenario.

Case Report: III° atrioventricular block due to fulminant myocarditis managed with non-invasive transcutaneous pacing.

Fulminant myocarditis is a life-threatening clinical condition. It is the inflammation of myocardium leading to acute heart failure, cardiogenic shock and cardiac arrhythmias. Incidence of fulminant myocarditis is low and mortality is high. Most grievous complications of fulminant myocarditis is mainly cardiac arrhythmias; if there is delay on active management of the patient, it may be fatal. Here, we describe a case of III° atrioventricular block due to fulminant myocarditis that was managed with non-invasive transcutaneous cardiac pacing in the absence of ECMO. The non-invasive transcutaneous pacemaker is a safe, effective and convenient device to revert arrhythmias.

Case Report: III° atrioventricular block due to fulminant myocarditis managed with non-invasive transcutaneous pacing

Fulminant myocarditis is a life-threatening clinical condition. It is the inflammation of myocardium leading to acute heart failure, cardiogenic shock and cardiac arrhythmias. Incidence of fulminant myocarditis is low and mortality is high. Most grievous complications of fulminant myocarditis is mainly cardiac arrhythmias; if there is delay on active management of the patient, it may be fatal. Here, we describe a case of III° atrioventricular block due to fulminant myocarditis that was managed with non-invasive transcutaneous cardiac pacing in the absence of ECMO. The non-invasive transcutaneous pacemaker is a safe, effective and convenient device to revert arrhythmias.

P106: Does training with a modified high-fidelity manikin improve junior residents’ ability to establish transcutaneous pacing in an advanced cardiovascular life support course?

Introduction: Transcutaneous cardiac pacing (TCP), a skill taught in Advanced Cardiovascular Life Support (ACLS) courses, is recommended to treat unstable bradycardia. Training manikins currently available fail to reproduce key features of TCP and might be suboptimal to teach this procedure.The objective of this study was to measure the impact of a modified high-fidelity manikin on junior residents’ TCP competency during an ACLS course. We hypothesized that the use of this high-fidelity manikin improves junior residents’ performances. Methods: This prospective cohort study was conducted at the Université de Montréal in July 2015 and 2016. First-year residents undergoing their mandatory ACLS course were enrolled. The control group (2015) received the traditional curriculum, which includes hands-on teaching on Advanced Life Support manikins. The intervention group (2016) received a similar curriculum, but used a modified high-fidelity manikin that reproduces key features of TCP (e.g. use of multifunction pads, TCP induced patient twitching, ECG artifacts). Cohorts were tested with a simulation scenario requiring TCP. Performances were graded based on six critical tasks: turns on pacer function, applies multifunction pads, recognizes TCP is ineffective, achieves captures, verifies mechanical capture and prescribes sedation. Our primary outcome was successful use of TCP defined as having completed all tasks. Secondary outcomes were the success rates for each task. These were compared using Pearson’s chi-squared test. We anticipated that the success rate of TCP would increase from 20% to 50%. To obtain a power of more than 90%, 48 participants were needed in both cohorts. Results: A total of 50 residents were recruited in both cohorts. No resident that received the traditional curriculum was able to successfully establish TCP while 18 residents trained on the modified high-fidelity manikin succeeded (0 vs 36%, P&amp;lt;0.001). Furthermore, the latter were more likely to recognize when pacing was inefficient (12 vs 86%, P&amp;lt;0.001), obtain ventricular capture (2 vs 48%, P&amp;lt;0.001), and check for a pulse rate to confirm capture (0 vs 48%, P&amp;lt;0.001). Conclusion: Successful use of TCP is a difficult skill to master for junior residents. A modified high-fidelity manikin during ACLS training significantly improves their ability to establish effective pacing.

The efficacy of transcutaneous cardiac pacing in ED

IntroductionTranscutaneous cardiac pacing (TCP) is a rapid, time-saving, and noninvasive ventricular stimulation that is tolerated by conscious patients despite the painful intervention for treatment of symptomatic bradycardias. The goal of this study was to determine the efficacy of TCP in unstable bradycardia patients in emergency department (ED). MethodsThis single-central, observational clinical study was conducted on patients older than 18 years who presented with acute unstable bradycardia to the tertiary care university ED. Primary outcome measure was to determine the efficacy of TCP in unstable bradycardia patients in the emergency settings. Efficacy of TCP was to determine changes of clinically significant vital signs and electrocardiography. ResultsOf 349 patients who visited the ED presenting with bradycardia, 89 patients who met the criteria were included in the study. There was a statistically significant difference between before and after the first administration TCP in mean systolic (71.2 [64.8-77.6] and 105.3 [97.6-112.9 mm Hg]) and diastolic blood pressure (42.9 [38.8-47.0] and 61.0 [56.4-65.5] mm Hg) and median heart rate (40 [39-42] and 74 [71-78] beats/min, P< .0001). ConclusionTranscutaneous cardiac pacing is a clinically effective treatment modality in patients with atropine-resistant unstable bradycardia.

High-fidelity simulation of transcutaneous cardiac pacing: characteristics and limitations of available high-fidelity simulators, and description of an alternative two-mannequin model.

Transcutaneous cardiac pacing (TCP) is a potentially lifesaving technique that is part of the recommended treatment for symptomatic bradycardia. Transcutaneous cardiac pacing however is used uncommonly, and its successful application is not straightforward. Simulation could, therefore, play an important role in the teaching and assessment of TCP competence. However, even the highest-fidelity mannequins available on the market have important shortcomings, which limit the potential of simulation. Six criteria defining clinical competency in TCP were established and used as a starting point in the creation of an improved TCP simulator. The goal was a model that could be used to assess experienced clinicians, an objective that justifies the additional effort required by the increased fidelity. The proposed 2-mannequin model (TMM) combines a highly modified Human Patient Simulator with a SimMan 3G, the latter being used solely to provide the electrocardiography (ECG) tracing. The TMM improves the potential of simulation to assess experienced clinicians (1) by reproducing key features of TCP, like using the same multifunctional pacing electrodes used clinically, allowing dual ECG monitoring, and responding with upper body twitching when stimulated, but equally importantly (2) by reproducing key pitfalls of the technique, like allowing pacing electrode misplacement and reproducing false signs of ventricular capture, commonly, but erroneously, used clinically to establish that effective pacing has been achieved (like body twitching, electrical artifact on the ECG, and electrical capture without ventricular capture). The proposed TMM uses a novel combination of 2 high-fidelity mannequins to improve TCP simulation until upgraded mannequins become commercially available.

Calcium Channel Blocker Toxicity in a Cirrhotic Patient

Objective To report a case of profound bradycardia as a result of verapamil toxicity due to impaired metabolism in acirrhotic patient. Case report A 57 year old man with cirrhosis presented with weakness and syncope and a heart rate of twenty beats per minute (bpm). Despite treatment with transcutaneous cardiac pacing, he developed a systole and required eight minutes of cardiopulmonary resuscitation before circulation was restored. After reviewing his medication list, verapamil toxicity was suspected as the etiology for his cardiovascular collapse because of the drug’s poor metabolic clearance in hepatic dysfunction. He was treated for calcium channel blocker toxicity, with calcium, insulin and dextrose infusions. By the seventh day, his blood pressure and heart rate were stable without invasive interventions. However, his liver was unable to recover from the initial shock, leading to the patient’s death. Discussion Calcium Channel Blocker (CCB) toxicity is associated with significant morbidity and mortality and is often diagnosed at the time of presentation (e.g. history of overdose). Treatment options include calcium infusion, which can lead to improvements in conduction, inotropy, and blood pressure; and high-dose insulin, which improves myocardial metabolism. These therapies were implemented in the patient, leading to hemodynamic stability, even in the setting of cirrhosis. Conclusion Caution is warranted when prescribing calcium channel blockers, such as verapamil, to patients with cirrhosis, since hepatic clearance will most likely be impaired, and may be associated with adverse events. If cirrhotic patients develop CCB toxicity, management is difficult, with few reports of specific treatment strategies.

Availability of decontamination, elimination enhancement, and stabilization resources for the management of acute toxic exposures and poisonings in emergency departments in Malaysia

Acute poisoning is a common medical emergency in Malaysia. Life can be saved if the patient is diagnosed properly and receives the appropriate treatment such as gastrointestinal decontamination techniques and resources to increase poison elimination according to clinical guidelines at a reasonable time. The aims of this study were to determine the availability of decontamination, elimination enhancement, and stabilization resources for the management of acute toxic exposures and poisonings in accident and emergency departments in Malaysia, and to compare the availability of such facilities among various types of hospitals. A comparative, descriptive cross-sectional study was conducted using a structured questionnaire. Seventy-four (58.3%) out of the targeted 127 hospitals replied and completed the questionnaire. The availabilities of most items related to stabilization resources were far better in general hospitals compared to district hospitals with specialists and district hospitals without specialists. These items were mechanical ventilators (p = 0.011), non-invasive positive pressure ventilators (0.024), pacemakers (p = 0.019), and transcutaneous cardiac pacing (p < 0.001). The availability of decontamination resources varied substantially with hospital type. Nevertheless, these differences did not reach statistical significance in any of the cases, whereas sodium sulphate, sorbitol, and polyethylene glycol were almost never available. The availabilities of most items related to elimination enhancement resources were far better in general hospitals and district hospitals with specialists compared to district hospitals without specialists. These items were haemodialysis (p = 0.046), haemoperfusion (p = 0.002), haemofiltration (p = 0.002), acid diuresis (p = 0.04), peritoneal dialysis (p < 0.001), and exchange transfusion (p < 0.001). Most Malaysian hospitals have certain important immediate interventions such as gastrointestinal decontamination techniques and resources to increase poison elimination. The availabilities of most facilities were far better in the general hospitals. Coordination between the National Poison Centre in Malaysia and hospitals should be established regarding the emergency facilities for effective management of poisoning cases in each hospital in order to direct the poisoned patients to the hospital where the appropriate management resources is available.

Thalidomide-induced Bradycardia in an Old Man

We presented a case of an 82-year-old man who had classic Kaposi sarcoma. He took thalidomide 100 mg twice daily for 23 days, and then he felt light-headedness and visited our emergency department. The heartbeat changes from baseline 80 beats per minute before administration of thalidomide to 45 beats per minute. About 25–50% of patients using thalidomide had mild bradycardia, and only 1–3% with severe bradycardia needed the assistance of inotropic agent or device (transcutaneous cardiac pacing). Emergency physicians should keep in mind current and concurrent medications in bradycardiac patients who are presented to the emergency department. If patients need thalidomide treatment, avoiding concomitant usage of beta-blocker and doing regular electrocardiogram monitoring are mandatory. In this case, atropine helps to improve the dizziness resulting from thalidomide-related bradycardia.

Evaluation of changes in cardiac biomarker concentrations and enzyme activities in serum after short- and long-duration transcutaneous cardiac pacing in dogs

To evaluate serum cardiac biomarker concentrations and selected enzyme activities in dogs with experimentally induced bradyarrhythmias after short- (1-hour) and long- (3-hour) duration transcutaneous cardiac pacing (TCP). 10 healthy Beagles. In each dog, anesthesia was induced with propofol (5 mg/kg, IV) and maintained via inhalation of isoflurane in oxygen. To induce bradyarrhythmia, diltiazem was administered IV (20 to 50 mg/dog). Transcutaneous cardiac pacing was performed for 1 hour (5 dogs) or 3 hours (5 dogs) by use of an automated external cardiac pulse generator and a transdermal electrode. Serum concentrations of creatine kinase-MB fraction and cardiac troponin I and activities of aspartate transaminase, creatine kinase, and lactate dehydrogenase were evaluated the day before (baseline) and at intervals until 7 days after TCP. Increases (from baseline) in serum cardiac biomarker concentrations and enzyme activities were detected in the long-duration TCP group; changes in the short-duration TCP group were more minor and largely not significant. Although severity of myocardial and skeletal muscular injuries was apparently greater with greater duration of TCP, the injuries were not persistent; most variables were within reference range within 3 days after TCP. Results indicated that application of TCP for > 1 hour in dogs may cause myocardial and skeletal muscular injuries. Serum concentrations of creatine kinase-MB fraction and cardiac troponin I and activities of aspartate transaminase, creatine kinase, and lactate dehydrogenase should be more carefully monitored after TCP of > 1 hour's duration to evaluate potential myocardial damages.

The optimal size and placement of transdermal electrodes are critical for the efficacy of a transcutaneous pacemaker in dogs

Transcutaneous cardiac pacing (TCP) can be used in dogs with a high risk for bradyarrhythmias prior to anesthesia, either in an emergency room or intensive care unit setting. Furthermore, TCP can also be used on patients diagnosed with bradyarrhythmias that require temporary pacing at the induction of anesthesia for the implantation of a permanent pacemaker. Despite the importance of TCP in emergency medicine, no studies have evaluated the optimal size and placement of the transdermal electrodes crucial for the efficacy of TCP in dogs. This study evaluated four different sizes of electrodes (10.5, 20, 30 and 40 cm2), and four different anatomical sites (anterior-posterior, left-right, apex-base, modified left-right) in order to optimize the efficacy of TCP in dogs. Electrodes with a surface area of 20 cm2 and a modified left-right placement minimized the pacing current and involuntary skeletal muscular contraction (muscular twitching) and so achieved the most optimal effect of TCP in dogs.

8 October 1958, D Day for the implantable pacemaker

After the introduction of temporary transcutaneous cardiac pacing by Paul Zoll in 1952, and of the temporary endocardial approach by Seymour Furman in the USA in 1958, the first definitive electronic pacemaker was implanted by Senning and Elmqvist in Sweden on 8 October 1958 using a thoracotomy to suture two epicardial electrodes. Actually, the ‘definitive’ unit placed in the abdominal wall of the pacemaker recipient, Arne Larsson, fired for only three hours. The first replacement, done the following morning, was followed by more than 22 units and numerous surgical interventions until Mr Larsson died in 2001.

Prehospital transcutaneous cardiac pacing for symptomatic bradycardia or bradyasystolic cardiac arrest: A systematic review

Advanced cardiac life support (ACLS) guidelines suggest transcutaneous cardiac pacing (TCP) for the treatment of symptomatic bradycardia (SB) and bradyasystolic cardiac arrest (BACA). Many EMS systems are extrapolating these guidelines and employing TCP in the prehospital setting. Our objective was to conduct a systematic review to determine the efficacy of prehospital TCP in the management of these two conditions. MEDLINE (1966-2004), EMBase and Science Citation Index (1980-2004) were searched using: prehospital/emergency medical services; external/transcutaneous; pacing. Two reviewer teams blinded to the source and author conducted a hierarchical selection (title, abstract, article) and quality assessment using a validated scale. Kappa agreement at each level of review was measured. Data abstraction was done by consensus. Thirty-four articles were identified and seven selected (Kappa agreement; title: 0.85, abstract: 0.78, full article: 0.82). Article quality was poor in all trials. There were three case series (BACA, n=215), three unblinded randomised controlled trials (one BACA, two BACA+SB), and one subgroup (SB) analysis. In the case series of paced BACA patients, 0/215 survived to hospital discharge. In the BACA trials 16/509 (paced) versus14/497 (control) survived to discharge. In a subgroup of one SB trial 5/6 (paced) versus 1/7 (control) survived to discharge (p=0.01). When a SB trial subgroup was combined with a case series 4/27 (paced) versus 0/24 (control) survived to discharge (p=0.07). In the prehospital setting, there is no evidence to support the use of TCP in bradyasystolic cardiac arrest. There is inadequate evidence to determine the efficacy of prehospital TCP in the treatment of symptomatic bradycardia.