Cardiac Pacemaker Patients Research Articles

Syncope in Patients with Cardiac Pacemakers.

IntroductionIt is challenging to diagnose syncope in patients with pacemakers. Because these patients have increased morbidity and mortality risks, they require immediate attention to determine the causes in order to provide appropriate treatment. This study aimed to investigate the causes and predictive factors of syncope as well as the methods used to diagnose syncope in cardiac pacemaker patients.MethodsPatients with pacemakers implanted owing to sinus node disease or atrioventricular block were evaluated with standardized questionnaires, endocavitary electrograms, and other tests based on the suspected causes of syncope. Mann-Whitney U tests were used to analyze continuous variables and Chi-squared or Fisher’s exact tests were used for categorical variables. Logistic regression was used for multivariate analyses. Statistical significance was P<0.05.ResultsThe study included 95 patients with pacemakers: 47 experienced syncope in the last 12 months and 48 did not. Of the 100 documented episodes of syncope, 48.9% were vasovagal syncopes, 17% had cardiac-related causes, 10.6% had unknown causes, and 8.5% had pacemaker failure. The multivariate analysis showed that a New York Heart Association (NYHA) Functional Class II was a significant factor for developing syncope (P<0.01).ConclusionWhile the most common type of syncope in pacemaker patients was neurally mediated, it is important to perform detailed evaluations in this population as the causes of syncope can be life-threatening. The best diagnostic methods were stored electrogram analysis and the tilt table test. NYHA Functional Class II patients were found to have a higher risk for syncope.

Preliminary findings on the safety of 1.5 and 3 Tesla magnetic resonance imaging in cardiac pacemaker patients.

Modern pacemakers are designed to allow patients to undergo magnetic resonance imaging (MRI) under a set of specific conditions. Aim of this study is to provide confirmatory evidence of safety and performance of a new pacing system (ImageReady™, Boston Scientific) in patients undergoing 1.5 and 3T MRI. Two prospective, nonrandomized, single-arm studies were designed to provide confirmatory data of no impact of MRI on device function, lead parameters, and patient conditions in subjects implanted with the system undergoing a clinically non-indicated 1.5T and 3T MRI, respectively. Device measurements were done within 1 hour before and after the scan and at 1 month follow-up. Thirty-two subjects underwent MRI visit (17 subjects with 1.5T MRI and 15 subjects with 3T MRI). There were no unanticipated adverse effects related to the pacemaker. Device measurements taken pre- and post-MRI scan did not show any clinical relevant change that could indicate an effect of the MRI on the device or at the lead-tissue interface (RV threshold change: 0.01±0.13 V, P = 0.60; RA threshold change: 0.01±0.11 V, P = 0.53; R wave change: -0.44±1.73 mV, P = 0.36; R wave change: 0.12±1.67 mV, P = 0.73), with data confirmed at 1-month follow-up visit. The study documented safety of the pacing system in the 1.5T and 3T MRI environment by showing no adverse events related to device or MRI scan. Additional data are required to cover the more complex scenarios involving different diagnostic needs, conditions of use, clinical conditions, and new emerging technologies.

Interference of implanted cardiac pacemakers with TASER X26 dart mode application

The prevalence of pacemaker patients among the general population and of conducted energy devices for law enforcement and self-defence is increasing. Consequently, the question on whether cardiac pacemaker patients are at particular risk becomes increasingly important, in particular, as the widespread use of such devices is planned in Europe. The risk of pacemaker patients has been investigated by numerical simulation at detailed anatomical models of patients with cardiac pacemakers implanted in left pectoral, right pectoral, and abdominal positions, with the monopolar electrode placed at the ventricular apex. The induced cardiac pacemaker interference voltages have been assessed for distant application of TASER X26 devices with dart electrodes propelled towards a subject. It could be shown that interference voltages are highest in abdominal pacemaker implantation, while they are about 20% lower in left or right pectoral sites. They remain below the immunity threshold level as defined by safety standards of implanted cardiac pacemakers and of implanted cardioverter defibrillators to prevent persisting malfunction or damage. However, induced voltages are high enough to be sensed by the pacemaker and to capture pacemaker function in case of hits at thorax and abdomen, frontal as well as dorsal.

Risk of Pacemaker Patients by TASER X26 Contact Mode Application

The prevalence of pacemaker patients among the general population and of conducted energy devices (CED) for law enforcement and self-defence is increasing. Consequently, the question whether cardiac pacemaker (CPM) patients are on particular risk becomes increasingly important. The risk of Taser X26 electric interference with implanted CPM has been investigated by numerical simulation at MRI-based anatomical models of CPM patients with devices implanted at conventional sites (left pectoral, right pectoral and abdominal) and with the monopolar CPM electrode placed at the ventricular apex. In spite of 10fold higher peak voltages the different coupling conditions make Taser-induced CPM interference voltages lower than those caused by external cardiac defibrillators. It is shown that electric interference considerably depends on ECD electrode orientation. The most unfavourable conditions are encountered with ECD electrodes aligned with the line from the CPM electrode tip to CPM can (EPC line). It could be shown that worst case interference voltages of monopolar pacemakers of any kind of implantation remain below the pulse immunity level as defined in safety standards of implantable cardiac pacemakers and of cardioverter defibrillators. However, interference voltages exceed CPM sensing thresholds. Therefore, capturing should be expected at Taser X26 contact mode application at any position at the upper part of the body including the abdomen, both at frontal and dorsal positions.

Usefulness of Management of Cardiac Pacemaker Implanted Patients by a Portable Electrocardiogram Monitoring System

Purpose: Opportunity has increased difficulty to periodical postoperative management of cardiac pacemaker implanted patients by aging and remote place. Therefore, we verified whether portable ECG monitor system would be effective and useful to these care. Object and Method: Objects are 50 cardiac pacemaker patients. 30 men and 20 women and average age was 76 years old. The implanted pacemaker mode was the various types of VVIR, AAIR, or DODR. Underlying diseases are advanced AV block, sinus bradycardia, bradycardic Af, and SSS. These patients was managed using a portable ECG monitor system to evaluate pacemaker condition et al. Result: The ECG was recorded all cases although noises in some elderly patients followed by acceptable ECG record. Pacemaker spike orrhythm have been certainly recognized by portable ECG as same as cases with 12 leads ECG. Moreover, there was no problem of data transmission with internet by the patient itself. During this study, the case which shows pacing insufficiency and remarkable battery consumption was not seen. Conclusion: Management of the pacemaker implanted patient by a portable ECG monitoring system was very effective and satisfied in accuracy. Frequency of a pacemaker check could probably be reduced from the field of patient satisfaction and convenience of life.

Analyze of the national production about pacemaker and orientations to cardiac pacemaker patients

Analyze of the national production about pacemaker and orientations to cardiac pacemaker patients

Unipolar cardiac pacemakers in electromagnetic fields of high voltage overhead lines

Experimental studies have shown that both electric and magnetic extremely low frequency fields are able to disturb a cardiac pacemaker (CPM) at certain field strengths. However, the simultaneous influence of multiphase electric and magnetic fields beneath high voltage overhead lines (HVOLs) has not yet been investigated. Therefore, the distribution of the electric and the magnetic field as well as the phase angle between both components for an exemplary HVOL was numerically calculated. The calculations show that the phase difference of the capacitive and the inductive induced voltage on the input of an implanted cardiac pacemaker is position-dependent. Based on these and our earlier results a worst-case-scenario for two virtual patients beneath an exemplary HVOL was derived. It turned out that although the interference of CPMs by the electromagnetic fields (EMFs) of HVOLs cannot be ruled out, the life-threatening interference condition ‘inhibition by EMF’ is unlikely. Due to various factors depending on technical parameters and the individual patient a definite answer about the disturbance of an implanted CPM beneath HVOLs can be given by studies with real CPM patients only.

Cheyne-stokes respiration associated with sleep disordered breathing is common in cardiac pacemaker patients with or without systolic dysfunction

Cheyne-stokes respiration associated with sleep disordered breathing is common in cardiac pacemaker patients with or without systolic dysfunction

Marcapasso cardíaco artificial: considerações pré e per-operatórias

JUSTIFICATIVA E OBJETIVOS: O avanço tecnológico da propedêutica médica diagnóstica em cardiologia difundiu grandemente a indicação de marcapasso (MP) cardíaco artificial, definitivo ou temporário. Isso fez com que outros especialistas, além dos cardiologistas, se envolvessem ainda mais no manuseio desses aparelhos. Quando pacientes portadores de MP se apresentam para cirurgia, a participação do anestesiologista pode ser decisiva para o sucesso do procedimento. O objetivo da presente revisão é familiarizar o anestesiologista com as principais indicações clínicas e com o funcionamento desses dispositivos, além dos cuidados pré e per-operatório que se deve ter. CONTEÚDO: Foram tratadas a classificação, funcionamento e as principais indicações clínicas para o implante de MP. Da mesma forma, procurou-se elucidar os principais cuidados pré e per-operatórios relativos ao uso de MP para lograr êxito no procedimento indicado. CONCLUSÕES: O principais conhecimentos sobre o funcionamento do MP e suas indicações clínicas devem fazer parte da prática diária do anestesiologista. Assim, o manuseio e a indicação do MP temporário amplia a atuação desses especialistas, além do que pode salvar vidas, inclusive em situações emergenciais dentro do centro cirúrgico. O uso de eletrocautério deveria ser evitado em portadores de MP.

Protection effects of a silver fiber textile against electromagnetic interference in patients with pacemakers

The use of the wireless cellular phone has increased dramatically, and this use could influence pacemaker function with electromagnetic interference (EMI). A textile lined with silver fiber has been developed for protection against electromagnetic waves. The purpose of this study was to evaluate the EMI protection effects in cardiac pacemaker patients wearing this textile. Participants in this study had pacemakers that were capable of obtaining endocardial electrograms, markers/annotations, and surface electrocardiograms via a programmer. A cellular phone was placed over the pulse generator. The presence of EMI was confirmed when a change in a parameter was observed. When EMI was confirmed, the subject wore a silver fiber shirt (rated at −30 dB), and EMI was evaluated. If the EMI persisted, the subject wore a heavier silver fiber shirt (rated at −50 dB), and again EMI was assessed. The same procedure was performed by using a ham radio device. Thirty-one subjects were tested. There was no EMI observed with the use of a cellular phone. However, interference by a ham device was confirmed in eight subjects (25.8%). Among six subjects, no further interference was observed after the patient wore a −30 dB shirt. For one subject, EMI was eliminated when a −50 dB shirt was used. However, one subject demonstrated persistent EMI when wearing a double layer of −30 dB and −50 dB shirts. Beneficial protection from EMI with the use of clothing lined with silver fiber has been demonstrated in this study. However, electromagnetic waves are diverse in both source and strength. Future studies are needed to confirm the benefits of wearing silver fiber clothing for the reduction of pacemaker–EMI interaction.

Sleep Apnea Syndrome in Patients with Cardiac Pacemaker

Background: Heart rhythm disturbances are cardiac side effects in patients with sleep-disordered breathing (SDB), which in itself is considered to be a risk factor for bradycardic rhythm disturbances. Objective: We analyzed the prevalence and degree of SDB in patients who received a cardiac pacemaker due to bradycardic rhythm disturbances and investigated the relationship between the severity of an underlying SDB and the type of heart rhythm disturbance. Methods and Results: 192 patients (100 males, 92 females, mean age 62.2 ± 12.2 years) were studied using the portable screening device MESAM IV. The respiratory disturbance index (RDI) was calculated visually. The mean RDI in all patients was 9.13 ± 11.09/h, 11.7 ± 13.15/h in males and 6.33 ± 7.42/h in females. The prevalence ratio of SDB between men and women was 1.7:1, with significant differences in the respective severity (p < 0.05). The screening showed a prevalence of SDB (RDI > 10/h) of 32.3%. The highest prevalence was found in the group of patients with atrial fibrillation and bradycardia. However, there were no significant differences compared to other types of rhythm disturbances. The RDI in the population studied depended on age and body mass index, but not on the existence or type of rhythm disturbance and not on concomitant diseases. Conclusion: The prevalence of SDB in cardiac pacemaker patients is similar to that in patients of comparable age without a pacemaker. A heart rhythm disturbance does not seem to be an independent risk factor for development of SDB. Nevertheless, the differential diagnosis of bradycardic rhythm disturbances in this age group should include a screening for sleep apnea.

Endoscopic diathermy in patients with cardiac pacemakers.

Malfunction of cardiac pacemakers related to diathermy in surgical procedures has been reported, but the risks of endoscopic diathermy in pacemaker patients is unknown. The aim of this study was to investigate current practice amongst British gastroenterologists regarding endoscopy in cardiac pacemaker patients. An anonymous postal questionnaire survey of 634 members of the Endoscopy section of the British Society of Gastroenterology was conducted. 410/634 (65%) replied. Respondents conducted 59270 endoscopic retrograde cholangiopancreatography procedures (ERCPs) and 88544 colonoscopies per year. 77.3% of respondents were aware of the possibility of adverse interactions between diathermy and pacemakers. 74.2% enquired whether a pacemaker was present prior to endoscopy. In cases where patients were known to have pacemakers fitted, 23.9% recorded an electrocardiogram (ECG) prior to endoscopic diathermy, 36.2% conducted ECG monitoring during the procedure, 35.9% consulted a cardiologist or pacemaker technician and 13.4% carried out specific preventative measures. 4.1% of all respondents were aware of instances of pacemaker malfunction having occurred during endoscopic diathermy. Most gastroenterologists surveyed were aware of the possibility of adverse interactions between diathermy and cardiac pacemakers, but few undertook measures to detect or prevent pacemaker malfunction. Endoscopic diathermy in cardiac pacemaker patients, however, appears generally safe, although the endoscopist should be aware of the small chance of an adverse interaction.

Exercise for Pacemaker Patients

In brief: Because cardiac pacemaker patients are a heterogeneous group, a graded exercise test using 1-met increments for robust patients and 1/2-met increments for frail patients should be performed before recommending an exercise program. Most patients are comfortable with a peak work load of 60% to 80% of their maximum capacity, and the physician can recommend an appropriate activity ranging from strolling at 1 mph (1/2 to 2 mets) to singles tennis (5 to 6 mets) based on the exercise test results. For most patients, a self-administered or supervised exercise program can be set up that will increase their capacity for sports or activities of daily living.