Pacemaker Malfunction Research Articles

Implication of real-time telemonitoring system in the diagnostics of cardiac diseases

Abstract Objectives We assessed the implication of a live telemonitoring system Check Point Cardio with real-time remote diagnostics in the diagnosis of a wide range of cardiac diseases- from rhythm disturbances to ischaemic heart disease. Methods and results In the period between 10.01.2017 and 10.01.2019 a total of 14172 patients were monitored. The mean monitoring period for the whole group was 7.76 (±4.5) days. The primary indication for real-time monitoring was rhythm and conduction abnormalities (66%) and ischemia detection (34%). In 2087 (14,8%) of the patient a clinically significant pathological finding was observed. A total of 603 (4,3%) patients were referred to a planned hospitalization with the most common reasons- ST segment deviation (450 pts), clinically significant bradycardia due to AV block- (21 pts); Sinus arrest/SA block (90 pts) and pacemaker malfunction in 20 patients, wide complex tachycardia was observed in 7 patients. In addition to that 42 patients were referred to an emergent hospitalization after a contact by our team. From those patients 30 were with ST segment elevation, 10 were with ST- segment depression and 2 were with sustained wide complex tachycardia. Conclusion Real-time telemonitoring accompanied with real-time remote diagnostics is a reliable method for diagnosis of wide-range cardiac diseases. The possibility of immediate diagnosis and contact with the patient, combined with GPS localization, allows a fast reaction in case of an emergent situation. Funding Acknowledgement Type of funding source: None

Pifalls in the interpretation of pacemaker ECGs

The analysis of the pacemaker ECG is usually regarded as difficult and may generate rather mediocre interpretations. It is acommon opinion that apacemaker ECG can only be analyzed if the type of pacemaker (single-, dual-, triple-chamber, manufacturer, model) and its programming are known. The following pitfalls illustrate how to achieve aclinically meaningful ECG interpretation in daily practice, even if these details are not known. Asystematic approach to ECG interpretation is particularly crucial in this context: Basic rhythm (Pwaves, intrinsic or paced rhythm), paced QRS complex (axis, width, bundle branch block morphology), signs of pacemaker malfunction (under‑/oversensing, loss of capture), arrhythmia to which the pacemaker reacts, or activity of any pacemaker algorithm. Many small details should not be overlooked and many questions can be answered if a few principles are applied. Understanding of the pacemaker ECG can improve the life of adevice patient at the touch of abutton.

Prospective analysis of a surgical algorithm to achieve ventilator weaning in cervical tetraplegia

Objectives: Chronic ventilator dependency in cervical tetraplegia is associated with substantial morbidity. When non-invasive weaning methods have failed the primary surgical treatment is diaphragm pacing. Phrenic nerve integrity and diaphragm motor units are requirements for effective pacing but may need to be restored for successful weaning. A surgical algorithm that includes: 1. Diaphragm pacing, 2. Phrenic nerve reconstruction, and 3. Diaphragm muscle replacement, may provide the capability of reducing or reversing ventilator dependency in virtually all cervical tetraplegics. Design: Prospective case series. Setting: A university-based hospital from 2015 to 2019. Participants: Ten patients with ventilator-dependent cervical tetraplegia. Interventions: I. Pacemaker alone, II. Pacemaker + phrenic nerve reconstruction, or III. Pacemaker + diaphragm muscle replacement. Outcome measures: Time from surgery to observed reduction in ventilator requirements (↓VR), ventilatory needs as of most recent follow-up [no change (NC), partial weaning (PW, 1–12 h/day), or complete weaning (CW, >12 h/day)], and complications. Results: Both patients in Group I achieved CW at 6-month follow-up. Two patients in Group II achieved CW, and in another two patients PW was achieved, at 1.5–2-year follow-up. The remaining two patients are NC at 6 and 8-month follow-up, respectively. In group III, both patients achieved PW at 2-year follow-up. Complications included mucous plugging (n = 1) and pacemaker malfunction requiring revision (n = 3). Conclusion: Although more investigation is necessary, phrenic nerve reconstruction or diaphragm muscle replacement performed (when indicated) with pacemaker implantation may allow virtually all ventilator-dependent cervical tetraplegics to partially or completely wean.

An innovative hybrid approach for detection of pacemaker pulses at low sampling frequency.

Accurate assessment of pacemaker function or malfunction is essential to make clinical interpretations on pacemaker therapy and patient symptoms. This article presents an innovative approach for detecting pacemaker pulses at sampling frequency as low as 125Hz. The proposed method is validated in wide range of simulated clinical ECG conditions such as arrhythmia (sinus rhythms, supraventricular rhythms, and AV blocks), pulse amplitudes (~100µV to ~3mV), pulse durations (~100µs to ~2ms), pacemaker modes and types (fixed-rate or on-demand single chamber, dual chamber, and bi-ventricular pacing), and physiological noise (tremor). The proposed algorithm demonstrates clinically acceptable detection accuracies with sensitivity and PPV of 98.1 ± 4.4 % and 100 %, respectively. In conclusion, the approach is well suited for integration in long-term wearable ECG sensor devices operating at a low sample frequency to monitor pacemaker function.Clinical Relevance- The proposed system enables real-time long-term continuous assessment of the proper functioning of implanted pacemaker and progression of treatment for cardiac conditions using battery-powered wearable ECG monitors.

Intermittent Pacemaker Malfunction Caused by Continuous Compression of the Lead by the Clavicle (Subclavian Crush Syndrome).

Subclavian vein access is still one of the most favoured access options for cardiac implantable electronic device (CIED) implantation. For the physician, the technique is reasonably familiar and easy to carry out. However, this has several potential complications. In this case, we present a late complication of subclavian access. The patient presented with intermittent loss of pacemaker output, which caused him to experience several syncopal events. In the acute setting, we changed the lead polarity and achieved a good outcome. Further management of this situation consisted of removal and replacement of the damaged lead.LEARNING POINTSSubclavian vein access is still one of the most favoured access options for cardiac device implantation.Intermittent loss of output can be a sign of pacemaker malfunction due to subclavian crush syndrome.Damaged lead extraction may be difficult to perform.

Electrocardiographic interpretation of pacemaker algorithms enabling minimal ventricular pacing

Cardiac pacing from the apex of the right ventricle has been shown to result in left ventricular dysfunction, atrial fibrillation, and increased mortality. To counter these effects, one of the strategies developed is avoidance of ventricular pacing when not necessary, using programmable algorithms to minimize ventricular pacing. Seven algorithms are available from 5 manufacturers. Four of the manufacturers have mode conversion algorithms that pace AAI(R) but, in the presence of failed atrioventricular (AV) conduction, demonstrate algorithm-offset and convert to DDD(R) with ventricular pacing. Three manufacturers do not have mode conversion but rather AV extension to encourage AV conduction. Each of these algorithms has a unique design and, when ventricular pacing is present, will regularly schedule conduction testing to encourage AV conduction and hence algorithm-onset. All of these algorithms seem to violate the rule of AV conduction by allowing the AV delay for sensed ventricular events to be longer than for ventricular paced events. The result is frequently bizarre electrocardiographic (ECG) appearances that often are unique to the company's algorithm but also suggest pacemaker malfunction. This review highlights and illustrates the features of these algorithms as they appear on ECG, and discusses other situations that result in unintended ventricular pacing.

The degree of translational and rotational movement of implanted pacemakers and cardioverter-defibrillators on coronal plane images in patients treated with radiotherapy for lung malignancy

Malfunction of both implantable cardiac pacemakers and cardioverter-defibrillators as a result of exposure to therapeutic radiation is a known risk in radiation therapy. Although guidelines are available to minimize this risk for low energy beams, the guidelines rely on the estimated doses of ionizing radiation received by the device. Implicit in this calculation is that there is minimal day-to-day movement in the position of the device. However, with the exception of the leads in some cases, the devices are not intentionally sewn to the surrounding tissue but simply placed in a pocket in the prepectoral fascial compartment. This surgical technique may allow for movement of the device which may result in differences to the actual dose received during a course of treatment. The author is unaware of prior studies that have examined this specific concern. Consequently, a total 12 patients with implantable pacemakers or cardioverter-defibrillators receiving radiotherapy were reviewed with a total of 206 daily treatment images available for analysis. Although, there was a large range in the medial-lateral and the superior-inferior position of these devices, the mean position of these devices differed only by 2 mm and 2 mm respectively when compared to the first day's images. Similarly, there was a large range in the daily rotation of the device but the mean difference in rotation was only 2 degrees in the counter-clockwise direction. However, some devices were noted to move up to 3.5 cm in the medial-lateral direction, 5.0 cm in the cranial-caudal direction, and to undergo up to 43 degrees of rotation in the counter-clockwise direction. Therefore, care must be taken when these devices are close to the edge of a treatment field.

Twiddler's Syndrome.

Twiddler’s syndrome refers to a rare condition in which a pacemaker or automatic implantable cardioverter-defibrillator (AICD) malfunctions due to coiling of the device in the skin pocket and resultant lead displacement. This image is the chest radiograph (CXR) of a 54-year-old male who presented to the emergency department with chest pain five months after his AICD was placed. The CXR shows AICD leads coiled around the device and the absence of leads in the ventricle consistent with Twiddler’s syndrome. Patients with twiddler’s syndrome should be admitted for operative intervention.

Continuous veno-venous hemodialysis and suspected pacemaker malfunction on telemetry monitoring

Continuous veno-venous hemodialysis and suspected pacemaker malfunction on telemetry monitoring

Safety considerations for performing robotic surgery in the presence of a permanent pacemaker.

With increasing experience, more complex patients are undergoing robotic surgery but the patient safety during these procedures remains paramount. Being a relatively recent technique of minimal access surgery, the safety and feasibility of robotic surgery is still under scrutiny. We recently performed two robotic procedures in patients who have permanent cardiac pacemaker. We believe this is the first published report through which it is shared and discussed, the preoperative and intraoperative management for these patients along with the importance of WHO checklist for safely performing robotic procedures. The importance of pre-procedure planning and briefing cannot be emphasised enough as these along with intraoperative management remain the key step in dealing with an adverse cardiac event due to permanent pacemaker malfunction.

Lymphoma in autopsy cases.

Lymphoproliferative disorders cause significant morbidity and mortality, either related to the disease itself or therapy complications. Some cases of lymphoma may have vague clinical presentation, especially in the absence of lymphadenopathy, and a clinical work up may not be conclusive. Our study focuses on autopsy cases of lymphoma patients, emphasizing clinically unsuspected cases. Autopsy records from the last 20years at our institution were searched, and the clinical parameters were recorded. Fifteen cases of lymphoma were identified, and 5 cases were diagnosed at the time of autopsy. Most B-cell lymphoma cases were mainly nodal disease, while T-cell lymphoma cases had widespread extra-nodal disease. Most deaths in B-cell lymphoma are due to infection/therapy induced immunosuppression, whereas T-cell lymphoma deaths are due to organ infiltration by lymphoma. Postmortem examination may reveal clinically unsuspected lymphoma, especially in rapidly deteriorating patients with vague presentation such as skin rash, bowel obstruction/bleeding or pacemaker malfunction.

TWIDDLER'S SYNDROME: AN UNUSUAL CAUSE OF REPEATED SHOCKS BY IMPLANTABLE CARDIOVERTER DEFIBRILLATOR

Twiddler's syndrome refers to malfunction of Pacemaker or Implantable Cardioverter Defibrillator (ICD) resulting from deliberate or unintentional twisting of pulse generator in device pocket resulting in lead dislodgment. We report a case of a 65 yo woman with multiple ICD shocks and anti-

AAV-mediated conversion of human pluripotent stem cell-derived pacemaker

Malfunction of nodal pacemaker (Pm) cardiomyocytes (CMs) due to diseases or aging leads to rhythm generation disorders, necessitating electronic Pm implantation. We functionally reprogrammed human pluripotent stem cell (hPSC) derived-ventricular (V) CMs into -PmCMs via recombinant adeno-associated virus serotype 9 (rAAV9)-mediated overexpression of engineered HCN1 channel (HCN1ΔΔΔ) whose S3-S4 linker has been strategically deleted by design to promote cardiac pacemaking. rAAV9-HCN1ΔΔΔ-reprogrammed hPSC-PmCMs converted from -VCMs showed automaticity and action potential parameters typical of native nodal PmCMs. Implantation of rAAV9-HCN1ΔΔΔ-based BPm in a preclinical porcine model of complete heart block significantly reduced the dependence on device-supported pacing and generated spontaneous heart rhythms from the BPm. Collectively, these results have further laid the groundwork on BPm for future translation.

Frequency of pacemaker malfunction associated with monopolar electrosurgery during pulse generator replacement or upgrade surgery

The aim of this study is to investigate the frequency of electrosurgery-related pacemaker malfunction. A retrospective study was conducted to investigate electrosurgery-related pacemaker malfunction in consecutive patients undergoing pulse generator (PG) replacement or upgrade from two large hospitals in Minneapolis, MN between January 2011 and January 2014. The occurrence of this pacemaker malfunction was then studied by using MAUDE database for all four major device vendors. A total of 1398 consecutive patients from 2 large tertiary referral centers in Minneapolis, MN undergoing PG replacement or upgrade surgery were retrospectively studied. Four patients (0.3% of all patients), all with pacemakers from St Jude Medical (2.8%, 4 of 142) had output failure or inappropriately low pacing rate below 30bpm during electrosurgery, despite being programmed in an asynchronous mode. During the same period, 1174 cases of pacemaker malfunctions were reported on the same models in MAUDE database, 37 of which (3.2%) were electrosurgery-related. Twenty-four cases (65%) had output failure or inappropriate low pacing rate. The distribution of adverse events was loss of pacing (59.5%), reversion to backup pacing (32.4%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The majority of these (78.5%) occurred during PG replacement at ERI or upgrade surgery. No electrosurgery-related malfunction was found in MAUDE database on 862 pacemaker malfunction cases during the same period from other vendors. Electrosurgery during PG replacement or upgrade surgery can trigger output failure or inappropriate low pacing rate in certain models of modern pacemakers. Cautions should be taken for pacemaker-dependent patients.

Response by Elagha and Weissman Regarding Article, “Pacemaker Malfunction Attributed to Multidetector Cardiac Computed Tomography”

We thank Verheyen et al for their thoughtful comments on the case we published1 concerning pacemaker inhibition during the performance of cardiac computed tomography. We would like to add some of the details requested so that the context of this event can be better understood, and therefore, its broader implications …

Syncope during pregnancy in a patient with permanent cardiac pacemaker, due to increased pacing threshold

A 22-year-old pregnant woman referred with syncope due to pacemaker malfunction. During the second trimester of pregnancy, the right ventricular (RV) lead pacing threshold increased and led to early generator depletion. We believe that this might happen due to lead micro-dislodgement or less probably effect of hormonal changes during pregnancy on electrode-myocardium interface.

Double twiddle trouble, a new variant of twiddler syndrome

The twiddler syndrome results in retraction and coiling of the lead in the pacemaker pocket with subsequent pacemaker malfunction. If the lead׳s parameters are not affected, then the problem can be corrected by lead repositioning. We describe the first reported case of a dramatic pacemaker lead coiling with a double level of lead compromise, with one of them being intra-cardiac. This condition affected our treatment strategy, as the repositioning of the lead was unfeasible.

Letter to the Editor: Marino et al. Inappropriate mode switching clarified by using a chest radiograph

To the Editor, I read with great interest the article by Marino et al. entitled “Inappropriate mode switching clarified by using a chest radiograph.” [1]. The authors have explained a case of dual-chamber pacemaker malfunction, caused by intermittent high-frequency noises. They claimed that this happened because of lead–lead interaction caused by excess slack of atrial and ventricular leads. In this case report, the authors did not explain the pacemaker parameters, such as the programmed lead sensation polarity (unipolar or bipolar), intrinsic R wave amplitude, and ventricular sensing threshold. With a close attention to the atrial and ventricular electrograms, it is clear that the noise is seen in both electrograms. The authors claimed that the noise is more prominent in the atrial channel than in the ventricular channel. However, this higher level of the noise in the atrial electrogram is due to automated gain, which increased the gain in the atrial channel. Thus, with the same gains, it seems that the noise amplitude will be the same, and changes in the amplitude in both the electrograms will be comparable at each moment. Replacement of the baseline with high-frequency signals, its simultaneity in both farfield electrograms, and no constant relation to the cardiac cycle are compatible with extra cardiac electromagnet interference. Myopotential oversensing is also presented with high-frequency noise, especially in widely spaced electrodes or unipolar electrograms, and can hence cause device malfunction, particularly when the sensing polarity is programed as unipolar. The effect of this interference may differ between atrial and ventricular electrograms, according to the distance from the sensing field of the electrodes. For excluding this possibility, it is better to look at the bipolar electrograms (recorded from closely spaced electrodes). Finally, as the authors have mentioned, some other possibilities, such as lead-connector problems, may present intermittently; however, the noise often saturates the amplifier range. Changes in the impedance may be documented during pocket manipulation [2]. Therefore, I recommend that the authors recheck the device settings such as sensing polarities and look for external electromagnetic interferences, as this is the most probable cause.

Anaesthetic challenges in a child with sickle-cell disease and congenital heart block.

Sir, We present a case report of anaesthetic management of a 12-year-old boy with sickle-cell disease (SCD) and congenital heart block (CHB) with pacemaker [Figure 1], undergoing laparoscopic splenectomy.Figure 1: 12-lead electrocardiography of the patientThe child had suffered sickle-cell crisis and pacemaker malfunction a month back. His preoperative investigations were normal and weight was 30 kg. He received intravenous (IV) fluids during fasting period, pneumococcal vaccine, antibiotic prophylaxis and cefotaxime 500 g IV. The cardiologist changed the mode of pacemaker to asynchronous (fixed rate). Standard American Society of Anesthesiologists monitoring, urine output and temperature monitoring were used. Morphine 4.5 mg IV, thiopentone 150 mg IV and atracurium 0.5 mg/kg IV were used for induction and intubation. Anaesthesia was maintained with isoflurane (MAC: 1.0), air and oxygen (FiO2: 0.5). Pneumoperitoneum was created with CO2 and intra-abdominal pressure was kept around 8–10 mmHg. The surgeon used bipolar cautery, blood loss was approximately 800 ml and 1 unit packed red cell was transfused. The patient was given fluid at 60 ml/h intra-operatively as he had been kept hydrated preoperatively. For post-operative analgesia, paracetamol 500 mg IV was given and skin incision was infiltrated with 12 ml 0.2% ropivacaine. Neuromuscular blockade was reversed and trachea was extubated. The patient remained haemodynamically stable, normothermic and had adequate urine output. Post-operative analgesia was maintained with paracetamol 500 mg IV 8th hourly and fentanyl boluses of 30 μg as rescue analgesic whenever visual analogue scale exceeded 3. The child was discharged on the 7th post-operative day after uneventful course. CHB (incidence 1 in 22,000 live births) with no structural abnormality and when diagnosis is established beyond neonatal period has better survival.[1] Intraoperatively, pacemaker mode is advised to be changed to asynchronous, and bipolar electrocautery is to be used. The availability of manual pacing should be ensured to manage pacemaker malfunction.[2] SCD is the disorder of beta-globin chain characterised by haemolytic anaemia, intermittent vascular occlusion, pulmonary compromise and multi-organ damage. Electrocardiogram changes are non-specific and first-degree heart block may be found.[34] Not usually associated with SCD, CHB in our patient is perhaps an additional finding. Splenectomy is recommended in children older than 2 years or after one major or two minor episodes of splenic sequestration crises.[34] When done laparoscopically, the duration of surgery increases, but hospital stay is decreased.[3] Any major surgery is associated with 7% mortality. Preoperatively, the history of episodes of painful crises must be sought.[4] Pre-operative examination should be thorough as SCD involves multiple organ systems. Neurological evaluation rules out the previous cerebrovascular accident as ischaemic infarcts are common in anaemic children.[3] Kidneys may get involved during advanced disease. Presence of rib infarcts can lead to hypoventilation. Perioperative cardiopulmonary manifestations such as acute chest syndrome usually remain undetected in young children.[34] As dehydration precipitates RBC sickling and occlusion of microvasculature at a level of precapillary sphincters, perioperative hydration must be ensured.[34] There is a controversy regarding blood transfusion, benefit being dilution of haemoglobin S and disadvantage being triggering of sickling.[34] Other factors leading to sickling crises are vascular stasis, hypoxia, metabolic acidosis, hypothermia and presence of infection.[3] Previous case reports have emphasised the importance of preventing sickling crisis perioperatively.[5] To conclude, perioperative anaesthetic management of children suffering from SCD and CHB needs meticulous pre-operative and intra-operative management and post-operative vigilance for preventing sickle-cell crisis and associated complications. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Right Bundle Branch Block as a Potential Cause of Pacemaker Malfunction.

A 68-year-old woman with permanent atrial fibrillation and a VVI pacemaker underwent catheter ablation of the atrioventricular junction. Before ablation, pacemaker interrogation confirmed correct functioning and it was programmed to VVI backup-pacing at 35 bpm. While positioning the ablation