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MR-guided focused ultrasound (MRgFUS) has proven its efficacy and safety for the treatment of essential tremor (ET) and/or Parkinson's disease (PD). However, having a cardiac pacemaker has been considered an exclusion criterion for the use of MRgFUS. Only 2 patients with a cardiac pacemaker treated with MRgFUS have been previously reported, both treated using 1.5-T MRI. In this paper, the authors present their experience performing 3-T MRgFUS thalamotomy in 4 patients with an implanted cardiac pacemaker. Treatments were uneventful regarding complications or severe side effects. MRgFUS using 3-T MRI was found to be an efficient and safe treatment for ET and/or PD in patients with an MRI-compatible pacemaker.

Mobitz type II second-degree atrioventricular block (AVB) is an electrocardiographic pattern that describes what appears to be an all-or-none conduction without visible changes in the AV conduction time or PR intervals before and after a single non-conducted P wave. An unchanged PR interval after the block is a sine qua non of Mobitz type II block. A 2:1 AVB cannot be classified in terms of type I or type II AVB. The diagnosis of Mobitz type II block AVB requires a stable sinus rate, which is an important criterion because a vagal surge (generally benign) can cause simultaneous sinus slowing and AV nodal block, which can resemble Mobitz type II AVB. Atypical forms of Wenckebach AVB may be misinterpreted as Mobitz type II AVB when a series of PR intervals are constant before the block. Concealed His bundle or ventricular extrasystoles may mimic both Wenckebach and/or type II AVB (pseudo-AVB). Correctly identified Mobitz type II AVB is invariably at the level of the His-Purkinje system and is an indication for a pacemaker., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Barold and Herweg.)

An 88-year-old patient underwent pacemaker generator replacement. Shortly after the replacement, the pacemaker pocket became swollen and, assuming a hematoma, underwent percutaneous drainage. However, the swelling was due to an aggressive lymphoma located in the pocket. This is the first described case of T-cell lymphoma in a pacemaker pocket., Competing Interests: Dr Santini has been a consultant for Boston Scientific, Abbott, and Medtronic; and has received speaker fees from Zoll. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

We present the first worldwide case of a hybrid surgical-percutaneous procedure involving transvenous lead extraction, concomitant tricuspid valve repair, implantation of an atrioventricular (AV) leadless pacemaker, and extravascular implantable cardioverter-defibrillator placement with suturing of the defibrillation lead to the heart wall. Multiple interventions were necessary as a result of active endocarditis, congenital complete AV block, and ventricular arrhythmia secondary prevention., Competing Interests: This work was supported by the Italian Ministry of Health-Ricerca Corrente to Centro Cardiologico Monzino IRCCS. Dr Tondo has served on the advisory boards of Medtronic and Boston Scientific; and has received lecture and grant travel fees from Medtronic, Abbott Medical, Boston Scientific, and Atricure. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

Reliability of power supply for current implantable electronic devices is a critical issue for longevity and for reducing the risk of device failure. Energy harvesting is an emerging technology, representing a strategy for establishing autonomous power supply by utilizing biomechanical movements in human body. Here, a novel "Twistron energy cell harvester" (TECH), consisting of coiled carbon nanotube yarn that converts mechanical energy of the beating heart into electrical energy, is presented. The performance of TECH is evaluated in an in vitro artificial heartbeat system which simulates the deformation pattern of the cardiac surface, reaching a maximum peak power of 1.42 W kg -1 and average power of 0.39 W kg -1 at 60 beats per minute. In vivo implantation of TECH onto the left ventricular surface in a porcine model continuously generates electrical energy from cardiac contraction. The generated electrical energy is used for direct pacing of the heart as documented by extensive electrophysiology mapping. Implanted modified carbon nanotubes are applicable as a source for harvesting biomechanical energy from cardiac motion for power supply or cardiac pacing., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

Background Despite being the most frequent complication following transcatheter aortic valve replacement (TAVR), optimal management of left bundle‐branch block (LBBB) remains unknown. Electrophysiology study has been proposed for risk stratification. However, the optimal timing of electrophysiology study remains unknown. We aimed to investigate the temporal dynamics of atrioventricular conduction in patients with new‐onset LBBB after TAVR by performing serial electrophysiology study and to deduce a treatment strategy. Methods and Results We assessed consecutive patients undergoing TAVR via His‐ventricular interval measurement prevalve and postvalve deployment and the day after TAVR. Infranodal conduction delay was defined as a His‐ventricular interval >55 milliseconds. Among 107 patients undergoing TAVR, 53 patients (50%) experienced new‐onset LBBB postvalve deployment and infranodal conduction delay was noted in 24 of 53 patients intraprocedurally (45%). LBBB resolved the day after TAVR in 35 patients (66%). In patients with new‐onset LBBB postvalve deployment and no infrahisian conduction delay intraprocedurally, the His‐ventricular interval did not prolong in any patient to >55 milliseconds the following day. Overall, 4 patients (7.5%) with new‐onset LBBB after TAVR were found to have persistent infrahisian conduction delay 24 hours after TAVR. During 30‐day follow‐up, 1 patient (1.1%) with new LBBB and a normal His‐ventricular interval after TAVR developed new high‐grade atrioventricular block. Conclusions Among patients with new‐onset LBBB postvalve deployment, infrahisian conduction delay can safely be excluded intraprocedurally, suggesting that early intracardiac intraprocedural conduction studies may be of value in these patients.

Current advancements in nanotechnology focus on miniaturization of electronic devices to provide power on demand. The Li+ ion based micro/nano‐batteries are excellent candidates for this purpose. However, the manufacture a single nano‐battery with assured reliable performance is one of the greatest challenges faced in the fabrication of Li+ ion based nano‐batteries. Nanostructured conducting polymers (NCPs) have shown promise in many frontier areas such as biosensors, microelectronics, polymer batteries, actuators, energy conversion etc. The combination of NCPs with inorganic compounds for designing nano‐batteries has been the subject of extensive investigation due to synergistic interaction of NCPs with inorganic compounds that provides remarkable improvement in electrode lifetime, rate capabilities, and voltage as well as mechanical and thermal stability. The present mini review deals with the fabrication of nano‐batteries using polypyrrole (PPy), polyaniline (PANI), and polythiophene (PTh) which could be utilized for various biomedical applications. The design and development of nano‐batteries using NCPs is discussed along with their applications in implantable devices, pace makers, smart sensing devices etc. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the nonlinear dynamics of a forced cardiac pacemaker model represented by a forced modified van der Pol oscillator by using the method of harmonic balance and the method of multiple time scales. The amplitudes of the forced harmonic, primary resonant state, super-harmonic and sub-harmonic resonant state oscillations are obtained and the effects of some system parameters on these amplitudes are investigated; hysteresis and jump phenomena are found. Three similar oscillators are then coupled together via time-delay coupling to model the heart rhythm and the effect of the coupling factor and time delay is also investigated. The overall model is then discretized using the fourth-order Runge–Kutta algorithm. A corresponding very high-speed integrated circuit hardware description language code is then written, synthesised and implemented using the Vivado-2017.4 software for the Artix7-xc7a35tftg256-1 field programmable gate array chip. The chip statistics, time series electrocardiograms and phase portraits of the model are derived; a good correlation between theoretical results (obtained with MATLAB program and Vivado software) and practical results is observed. [ABSTRACT FROM AUTHOR]

Wireless charging devices for implantable cardiac pacemakers have not been clinically applied. For actual applications, safety assessments of a wireless charging system must be conducted. For systems with a certain power, frequency is one of the important factors that directly affect safety. This paper aims to study the safety evaluation method and optimal operation frequency of a cardiac pacemaker wireless charging system. The wireless power transfer (WPT) model considering the coils’ AC resistance is established, which is more in line with the actual situation. The analytical solution to the current in coupling coils is derived, which reveals the effect of the frequency. The currents used in electromagnetic and thermal simulations are calculated or measured for different charging prototypes. A safety evaluation method that comprehensively considers specific absorption rate (SAR), electric field, efficiency, temperature rise and electromagnetic interference (EMI) is proposed. In particular, the temperature rise is an innovative perspective as it has rarely been studied in previous literatures. The optimal frequency of a 3 W wireless charging system for cardiac pacemaker is determined based on the results of safety evaluation. The theoretical temperature rise reaches the minimum at 203 kHz, and the theoretical energy loss reaches the minimum at 260 kHz. The comfort and safe frequency band is approximately from 150 kHz to 370 kHz based on theoretical and experimental results, and the optimal frequency band from 200 kHz to 300 kHz is recommended. [ABSTRACT FROM AUTHOR]

Background Inadvertent lead malposition (ILM) in the left ventricle (LV) via the subclavian artery is a rare complication during the insertion of cardiac implantable electronic devices (CIED). If not identified, there is a risk of systemic thromboembolism. Transarterial pacing lead extraction often requires surgical removal and carries high risks of bleeding and thromboembolism, but percutaneous extraction has also been previously described. Case summary A 71-year-old female presented with left homonymous hemianopia on Day 1 post-insertion of a dual-chamber permanent pacemaker (PPM). A computed tomography (CT) angiogram of the brain and aortic arch revealed an acute occlusion of a branch of the right posterior circulating artery (PCA) and a malpositioned pacing lead in the left subclavian artery. Urgent percutaneous removal of the transarterial lead using the retained wire technique was successfully performed. Discussion Inadvertent lead malposition in the arterial system is rare and often requires lead extraction due to systemic thromboembolic complications. The retained wire technique has been previously described for percutaneous transvenous lead extraction and exchange, but to our knowledge, we are the first to report utilizing this technique for transarterial lead extraction. Using a case report, we highlight the utility, safety, and effectiveness of the retained wire technique in extracting a malposition lead in the subclavian artery and LV. [ABSTRACT FROM AUTHOR]

Abstract Background Misconceptions regarding activities after pacemaker implantation can result in restrictions in daily life. This study aims at measuring the correction of misconceptions following an educational intervention utilizing a picture based brochure and personal counseling. Methods One hundred and twenty-eight patients were enrolled in a quasi experimental study on the day after pacemaker implantation. Patients’ perceptions about safety of various daily activities, medical procedures, and usage of appliances, in the presence of pacemaker was assessed using a questionnaire before and ten days after an educational intervention using a pictorial brochure. The number of correct responses before and after the intervention was compared to assess the change in patients’ perception. Results A total of 128 patients were interviewed at baseline, of which 115 followed-up at 10 days. Mean age of patients was 60.31 ± 12.81 years. In total, 76 (59.4%) were male and 61(47.7%) were illiterate. Mean correct responses increased from 64.47 ± 29.48% to 92.29 ± 14.42% (p

MitraClip (Abbott Vascular, Inc., Santa Clara, California) has emerged as a viable alternative for treatment of symptomatic severe mitral regurgitation. Conduction abnormalities are not a known complication of this procedure. We report a case of complete heart block without a ventricular escape rhythm immediately following MitraClip placement near the medial leaflets (A3-P3) in a patient with underlying trifascicular block. (Level of Difficulty: Intermediate.)

Thanks to an unusual reversible cause of reflex syncope, a young physician avoided pacemaker implantation. We present the treatment of a bizarre case of gastro-cardiac syndrome, an oftenoverlooked clinical entity. [ABSTRACT FROM AUTHOR]

Upper venous system anatomic variations may cause difficulties during cardiac pacemaker implantation. Persistent left superior vena cava (PLSVC) and absent right superior vena cava could be an arrhythmogenic source of atrial arrhythmias and cardiac conduction disease. We represent dual-chamber pacemaker implantation in a patient with a very rare upper venous system anomaly, paroxysmal atrial fibrillation, sick sinus syndrome, that cause unusual fluoroscopic image.

We report a case of persistent left superior vena cava (PLSVC), discovered by chance during the cardiac electronic device placement procedure. PLSVCs are congenital anomalies of the thoracic vasculature, during which remnants of the left superior vena cava drain into the right atrium through the coronary sinus. PLSVCs can vary in their location and overall anatomy. In patients with PLSVC, implantation of a cardiac electronic device is associated with an increased risk of technical difficulties the entire procedure.

Amiodarone is a class III anti-arrhythmic drug which is commonly used in various cardiac arrhythmias. Hypothyroidism is one important complication linked with this drug. Herein, we recount a case of amiodarone-induced hypothyroidism, which presented as atrial fibrillation (AF) with slow ventricular response. A middle-aged gentleman was brought to the casualty in unconscious state. He was a known case of hypertension and on amiodarone treatment for AF for the past 2 years. On presentation, the patient had a slow pulse rate and his electrocardiogram was suggestive of AF with very slow ventricular beat. This was managed medically and a temporary cardiac pacemaker was instituted thereafter. In search of the cause for bradycardia, his thyroid function test depicted hypothyroidism with 2-fold raised thyroid-stimulating hormone and decreased levels of free tetraiodothyronine hormone, but the patient had no other features suggestive of hypothyroidism. Therefore, the patient was started on oral thyroxine hormone, which led to considerable pulse rate improvement.

An 86-year-old man with paroxysmal atrial fibrillation on flecainide, a class IC antiarrhythmic, presented with cardiac arrest. The patient had extremely wide QRS complexes with inconsistent pacemaker capture on electrocardiography. Due to cardiac failure and renal failure, the patient developed progressive flecainide toxicity, which led to pacemaker failure, and ultimately, death. (Level of Difficulty: Beginner.)

We report a unique case of delivery of inappropriate implantable cardioverter-defibrillator therapies related to a “perfect storm”: presence of an integrated lead, insufficient lead slack related to right heart dilation resulting in shock coil misplacement, myocarditis with loss of R waves, and the concomitant occurrence of an incessant atrial tachycardia. (Level of Difficulty: Advanced.)

Iatrogenic complications may manifest in a variety of ways. We present the case of an 86-year-old woman who underwent a percutaneous coronary intervention with a drug-eluting stent for non–ST-segment elevation myocardial infarction followed by leadless pacemaker placement through a femoral approach. Her post-procedure course was complicated by new onset high-output heart failure secondary to iatrogenic arteriovenous fistula formation, requiring covered stent placement. (Level of Difficulty: Advanced.)

The reuse pacemakers is a beneficial technique for patients in countries with a low economic standard of living where health care is almost non-existent. We offered to share the experience of Senegal on the reconditioning of pacemakers. We conducted a retrospective study over a period from January 2015 to December 2020 including all patients who benefited from a reconditioned pacemaker for primary implantation or reimplantation. The criteria for reconditioning pacemakers are the absence of dysfunction or damage and a residual battery life of more than 5 years of the pacemaker. Refurbished pacemakers are acquired either from deceased families or from extraction centers. Sterilization is carried out using phenoxypropanol + benzalkonium chloride solution, 70% ethanol and ethylene oxide. We collected 161 patients during the study period, including 77 men (48%) and 84 women (52%), i.e. a M/F sex ratio of 0.94. The average age of the population was 65 years. Functional symptomatology was dominated by syncope in 54%. Electrocardiographically, 72% of patients were in complete atrioventricular block. A primary implantation was noted in 91.5% of patients. The vascular approach most used during implantation was cephalic in 49.5% of cases. In our series, we noted that 58% of patients had benefited from temporary stimulation before implantation. At implantation, single-chamber stimulation was used in 60% of patients and 46.5% of patients had programming in VVI mode. We had 5.5% major complications with 3% box infection occurring between 3 and 6 months post-implantation and 2.5% pacemaker syndrome. We noted 1 case of death linked to underlying heart disease. Reconditioning of cardiac pacemakers is a safe and beneficial therapeutic strategy for patients. In Senegal, reconditioning has shown satisfactory results. In our countries this technique can be an alternative for certain patients. [ABSTRACT FROM AUTHOR]

Heart rate is accelerated to match physiological demands through the action of noradrenaline on the cardiac pacemaker. Noradrenaline is released from sympathetic terminals and activates β1-and β2-adrenergic receptors (ΑRs) located at the plasma membrane of pacemaker cells. L-type calcium channels are one of the main downstream targets potentiated by the activation of β-ARs. For this signaling to occur, L-type calcium channels need to be located in close proximity to β-ARs inside caveolae. Although it is known that aging causes a slowdown of the pacemaker rate and a reduction in the response of pacemaker cells to noradrenaline, there is a lack of in-depth mechanistic insights into these age-associated changes. Here, we show that aging affects the formation and function of adrenergic signaling microdomains inside caveolae. By evaluating the β1 and β2 components of the adrenergic regulation of the L-type calcium current, we show that aging does not alter the regulation mediated by β1-ARs but drastically impairs that mediated by β2-ARs. We studied the integrity of the signaling microdomains formed between L-type calcium channels and β-ARs by combining high-resolution microscopy and proximity ligation assays. We show that consistent with the electrophysiological data, aging decreases the physical association between β2-ARs and L-type calcium channels. Interestingly, this reduction is associated with a decrease in the association of L-type calcium channels with the scaffolding protein AKAP150. Old pacemaker cells also have a reduction in caveolae density and in the association of L-type calcium channels with caveolin-3. Together the age-dependent alterations in caveolar formation and the nano-organization of β2-ARs and L-type calcium channels result in a reduced sensitivity of the channels to β2 adrenergic modulation. Our results highlight the importance of these signaling microdomains in maintaining the chronotropic modulation of the heart and also pinpoint the direct impact that aging has on their function. [ABSTRACT FROM AUTHOR]

• Noise-related interferences during exposureoccurred in 84% of the devices. • Potentially harmful effects were found in 34% of the ICDs. • Irreversible effects on battery life occurred in only non-MRI-compatible devices. • RTmay cause damage and malfunction in a consistent number of older-generations PMs and ICDs. Radiotherapy may cause malfunction of implantable cardioverter-defibrillators (ICDs) and pacemakers (PMs). We carried-out a multicentre randomized in-vitro study on 65 ICDs and 145 PMs to evaluate malfunctions during and after direct irradiation to doses up to 10 Gy. Three centres equipped with different linear accelerator and treatment-planning systems participated in the study. Computed Tomography (CT) acquisitions were performed to build the treatment plans. All devices were exposed to dose of 2, 5, or 10 Gy (6 MV). All devices underwent a baseline examination and 64 wireless real-time telemetry - transmissions (47 ICDs and 17 PMs) were monitored during photon exposures. All devices were interrogated after exposure and once monthly for six subsequent months. Fifty-four of the 64 wireless-enabled CIEDs (84.4%) recorded noise-related interferences during exposure. In detail, 40/47 ICDs (85.1%) reported interference, of which 16 ICDs (34%) reported potentially clinically relevant pacing inhibition and inappropriate detections. Following exposure, a soft reset occurred in 1/145 PM (0.7%) while 7/145 PMs (4.8%) reported battery issues. During the six-month follow-up, 1/145 PM (0.7%) reported a soft reset, while 12/145 more PMs (8.3%) and 1/64 ICD (1.5%) showed abnormal battery depletion. All reported issues occurred independently of exposure dose. Finally, irreversible effects on software and battery life occurred in only non-MRI-compatible devices. ICDs mostly featured real-time transient sensing issues, while PMs mostly experienced long-term battery or software issues that were observed immediately following radiation exposure and during follow-up. Irreversible effects on battery life and software occurred in only non-MRI-compatible devices. [ABSTRACT FROM AUTHOR]

The cardiac pacemaker ignites and coordinates the contraction of the whole heart, uninterruptedly, throughout our entire life. Pacemaker rate is constantly tuned by the autonomous nervous system to maintain body homeostasis. Sympathetic and parasympathetic terminals act over the pacemaker cells as the accelerator and the brake pedals, increasing or reducing the firing rate of pacemaker cells to match physiological demands. Despite the remarkable reliability of this tissue, the pacemaker is not exempt from the detrimental effects of aging. Mammals experience a natural and continuous decrease in the pacemaker rate throughout the entire lifespan. Why the pacemaker rhythm slows with age is poorly understood. Neural control of the pacemaker is remodeled from birth to adulthood, with strong evidence of age-related dysfunction that leads to a downshift of the pacemaker. Such evidence includes remodeling of pacemaker tissue architecture, alterations in the innervation, changes in the sympathetic acceleration and the parasympathetic deceleration, and alterations in the responsiveness of pacemaker cells to adrenergic and cholinergic modulation. In this review, we revisit the main evidence on the neural control of the pacemaker at the tissue and cellular level and the effects of aging on shaping this neural control. [ABSTRACT FROM AUTHOR]

Copyright of Herz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Primary facial spasm accompanied by arrhythmia is a rare clinical phenomenon and has not been reported before. We describe this phenomenon and discuss its mechanism and treatment. Case presentation We herein present a rare case of a patient with left primary facial spasm and a third-degree atrioventricular block (III degree AVB), who was implanted with a temporary cardiac pacemaker to receive microvascular decompression (MVD) because of refusal of a permanent cardiac pacemaker. The symptoms of facial spasm disappeared after MVD. The temporary cardiac pacemaker was removed on the second day after surgery. Her ECG still showed the third-degree atrioventricular block after a follow-up period of 5 months. Conclusions We are the first to report a patient with facial spasm and arrhythmia who was implanted with a temporary cardiac pacemaker to receive MVD. This case report demonstrated that the concomitant presence of a III degree AVB maybe not a contraindication for MVD, and the etiology of this facial spasm was the actual vascular compression of the facial nerve entry zone that was not related to the atrioventricular block.

We present the case of a 63-year-old female patient who presented to the pacemaker clinic for a scheduled interrogation of her leadless pacemaker. The device interrogation was suggestive of intermittent under-sensing with failure to pace. Connecting the electrocardiogram lead to the pacing system analyzer raised the suspicion of intermittent loss of telemetry data. (Level of Difficulty: Beginner.)

His bundle pacing was developed while seeking a physiological alternative to biventricular cardiac resynchronization therapy. However, His bundle pacing may not be adequate in all patients. In this scenario, left bundle branch pacing has arisen as a new cardiac resynchronization therapy modality to correct left bundle branch block and restore ventricular synchrony. (Level of Difficulty: Intermediate.)

A 59-year-old male was admitted with acute on chronic decompensated heart failure. Review of his CardioMEMS (Abbott Laboratories, Atlanta, Georgia) device and HeartLogic (Boston Scientific, Marlborough, Massachusetts) index were helpful in guiding management of his volume status. This paper highlights the correlation between 2 monitoring systems which could be used to predict heart failure events. (Level of Difficulty: Intermediate.)

Abstract Background The effectiveness of electrochemotherapy of tumors (ECT) and of irreversible electroporation ablation (IRE) depends on different mechanisms and delivery protocols. Both therapies exploit the phenomenon of electroporation of the cell membrane achieved by the exposure of the cells to a series of high-voltage electric pulses. Electroporation can be fine-tuned to be either reversible or irreversible, causing the cells to either survive the exposure (in ECT) or not (in IRE), respectively. For treatment of tissues located close to the heart (e.g., in the liver), the safety of electroporation-based therapies is ensured by synchronizing the electric pulses with the electrocardiogram. However, the use of ECT and IRE remains contraindicated for patients with implanted cardiac pacemakers if the treated tissues are located close to the heart or the pacemaker. In this study, two questions are addressed: can the electroporation pulses interfere with the pacemaker; and, can the metallic housing of the pacemaker modify the distribution of electric field in the tissue sufficiently to affect the effectiveness and safety of the therapy? Results The electroporation pulses induced significant changes in the pacemaker ventricular pacing pulse only for the electroporation pulses delivered during the pacing pulse itself. No residual effects were observed on the pacing pulses following the electroporation pulses for all tested experimental conditions. The results of numerical modeling indicate that the presence of metal-encased pacemaker in immediate vicinity of the treatment zone should not impair the intended effectiveness of ECT or IRE even when the casing is in direct contact with one of the active electrodes. Nevertheless, the contact between the casing and the active electrode should be avoided due to significant tissue heating at the site of the other active electrode for the IRE protocol and may cause the pulse generator to fail to deliver the pulses due to excessive current draw. Conclusions The observed effects of electroporation pulses delivered in close vicinity of the pacemaker or its electrodes do not indicate adverse consequences for either the function of the pacemaker or the treatment outcome. These findings should contribute to making electroporation-based treatments accessible also to patients with implanted cardiac pacemakers.

Heart rate is accelerated to match physiological demands through the action of noradrenaline on the cardiac pacemaker. Noradrenaline is released from sympathetic terminals and activates β1-and β2-adrenergic receptors (ΑRs) located at the plasma membrane of pacemaker cells. L-type calcium channels are one of the main downstream targets potentiated by the activation of β-ARs. For this signaling to occur, L-type calcium channels need to be located in close proximity to β-ARs inside caveolae. Although it is known that aging causes a slowdown of the pacemaker rate and a reduction in the response of pacemaker cells to noradrenaline, there is a lack of in-depth mechanistic insights into these age-associated changes. Here, we show that aging affects the formation and function of adrenergic signaling microdomains inside caveolae. By evaluating the β1 and β2 components of the adrenergic regulation of the L-type calcium current, we show that aging does not alter the regulation mediated by β1-ARs but drastically impairs that mediated by β2-ARs. We studied the integrity of the signaling microdomains formed between L-type calcium channels and β-ARs by combining high-resolution microscopy and proximity ligation assays. We show that consistent with the electrophysiological data, aging decreases the physical association between β2-ARs and L-type calcium channels. Interestingly, this reduction is associated with a decrease in the association of L-type calcium channels with the scaffolding protein AKAP150. Old pacemaker cells also have a reduction in caveolae density and in the association of L-type calcium channels with caveolin-3. Together the age-dependent alterations in caveolar formation and the nano-organization of β2-ARs and L-type calcium channels result in a reduced sensitivity of the channels to β2 adrenergic modulation. Our results highlight the importance of these signaling microdomains in maintaining the chronotropic modulation of the heart and also pinpoint the direct impact that aging has on their function.

The roles of the resting heart rate (RHR) have been actively investigated and increasingly recognized in recent decades, because of the growing evidence that fast RHR is associated with and predicts the risk of developing cardiovascular and metabolic disorders, as well as all-cause mortality. Long-chain omega-3 polyunsaturated fatty acids (PUFAs) (eg, eicosapentaenoic acid and docosahexaenoic acid) have been shown to have chronotropic effects on heartbeat in both healthy people and patients with various disease conditions. The aims of this review are (1) to briefly summarize the importance of elevated RHR in disease pathogenesis and mortality; (2) to provide an update on the negative chronotropic effect of omega-3 PUFAs on the heart; (3) to highlight how omega-3 PUFAs regulate heart rate through the autonomic nervous system – a central control mechanism; and (4) to highlight how omega-3 PUFAs modulate the trans-membrane ionic channels in cardiomyocytes – a fundamental mechanism of cardiac automaticity. Eicosapentaenoic acid and docosahexaenoic acid are nutrients derived from some aquatic organisms, and they can also be converted from digested oily seeds and nuts of some terrestrial plants in the body. The consumption of omega-3 PUFAs for RHR reduction represents a lifestyle modification for risk factor management and promises nutritional benefits for public health improvement. [ABSTRACT FROM AUTHOR]

Background: Surgical procedures in patients suffering from coronavirus disease 2019 (COVID‑19) are possible under strict hygiene and protective measures and are currently carried out regularly. This study examined how much additional work this involves. Material and methods: A structured evaluation of 71 surgical procedures performed at the Augsburg University Hospital between 1 November 2020 until 31 December 2020 was carried out. The operations on COVID‑19 patients were compared to procedures on non-COVID‑19 patients with respect to temporal, structural and staff resources, exemplified by four interventions: transbrachial embolectomy, total hip arthroplasty (H-TEP), proximal femoral nail antirotation (PFN-A) and new implantations of cardiac pacemakers. Results: The incision to suture times between the interventions in patients with COVID‑19 and non-COVID‑19 patients did not show any significant differences in any of the four interventions evaluated. The postoperative monitoring in the operating room, which is identified as time-consuming in many interventions, was often circumvented by postoperative transfer to the intensive care unit or by the use of local anesthetic procedures. For major operations, such as H‑TEP, the preparation time was shown to be significantly longer (p = 0.037). Furthermore, there was a significantly higher requirement for anesthesia nursing personnel of 1.5 vs. 1.0 (p = 0.02). Conclusion: A quantification of the additional effort of operative treatment is difficult due to the already complex care of COVID‑19 patients; however, it can be assumed that there is an increased need for additional human and structural resources due to the supply of material from outside the operating room, which is not documented in the standard recording. [ABSTRACT FROM AUTHOR]

The work presented describes the modeling of a measurement bench in the presence of an implantable single-chamber pacemaker in vitro subjected to a conducted disturbance. The source of disturbance is a sinusoidal electrical signal with amplitude of 10 V; the frequency ranges studied correspond to the frequencies of the electrical distribution network (50/60 Hz) and to the frequencies of domestic applications (10/25KHz). The numerical simulations were carried out according to two methods, the first based on the finite element method using the Comsol multiphysics software, the second is based on the impedance method. The results obtained by the two methods are in good agreement, and this will allow us to calculate the voltage induced between the ends of the stimulator. These results allowed us to validate the proposed model. [ABSTRACT FROM AUTHOR]

Aims: To develop a suite of quality indicators (QIs) for the evaluation of the care and outcomes for adults undergoing cardiac pacing.Methods and Results: Under the auspice of the Clinical Practice Guideline Quality Indicator Committee of the European Society of Cardiology (ESC), the Working Group for cardiac pacing QIs was formed. The Group comprised Task Force members of the 2021 ESC Clinical Practice Guidelines on Cardiac Pacing and Cardiac Resynchronization Therapy, members of the European Heart Rhythm Association, international cardiac device experts, and patient representatives. We followed the ESC methodology for QI development, which involved (i) the identification of the key domains of care by constructing a conceptual framework of the management of patients receiving cardiac pacing, (ii) the development of candidate QIs by conducting a systematic review of the literature, (iii) the selection of the final set of QIs using a modified-Delphi method, and (iv) the evaluation of the feasibility of the developed QIs. Four domains of care were identified: (i) structural framework, (ii) patient assessment, (iii) pacing strategy, and (iv) clinical outcomes. In total, seven main and four secondary QIs were selected across these domains and were embedded within the 2021 ESC Guidelines on Cardiac Pacing and Cardiac Resynchronization therapy.Conclusion: By way of a standardized process, 11 QIs for cardiac pacing were developed. These indicators may be used to quantify adherence to guideline-recommended clinical practice and have the potential to improve the care and outcomes of patients receiving cardiac pacemakers. [ABSTRACT FROM AUTHOR]

Summary: Implantable cardiac pacemakers are equipped with batteries to provide power supply that have a limited lifetime. Battery‐based implantable cardiac pacemakers need surgical intervention to replace batteries. This is an undesirable condition that can increase the risk of complications and costs for patients. To overcome the above shortcomings, a batteryless cardiac pacemaker is introduced, which harvests energy from the body temperature. In this article, a batteryless cardiac pacemaker is designed, which is powered by sustainable energy sources. Hence, thermoelectric generators (TEGs) are considered the sustainable renewable energy source that powers up cardiac pacemakers with effective reduction in dimension without limiting the capacity. Then, power electronic converters adapted with TEGs has enhanced the ability of controlling environmental conditions as well as maximizing energy harvesting. Therefore, a DC‐DC converter is designed with TEG to solve environmental conditions issues of TEG. In this proposed methodology, a TEG with three different types of DC‐DC converters is designed and validated to analyze the performance of converters such as boost converter, buck converter, and buck‐boost converter. The proposed design was analyzed based on a case example and simulated using Cadence Capture CIS. Finally, a prototype of our design was developed to evaluate the experimental outcome. Four modules are designed and validated: general pacemaker, TEG with pacemaker, TEG with boost converter, TEG with buck converter, and TEG with buck‐boost converter. Finally, a prototype of a general cardiac pacemaker is designed to compare the real‐time performance with the simulation analysis. [ABSTRACT FROM AUTHOR]

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An electrode resistance monitoring circuit utilizing current comparison is proposed and demonstrated for implantable cardiac pacemakers. The resistance detection circuit compares the electrode resistance with the reference resistance in a highly-symmetrical topology based on current reference. It works in deep sub-threshold region with ultra-low power consumption. However, it is able to achieve a resistance detection threshold as low as several kilo Ohm. The circuit is implemented in 0.35-μm CMOS process. It consumes only 164 nA in monitoring mode and achieves reliable resistance detection threshold of 4.5 kΩ. The measurement results of 50 samples verify that it's qualified for application in implantable cardiac pacemakers. [ABSTRACT FROM AUTHOR]

We describe the case of a 79-year-old woman with a history of Erdheim-Chester disease who presented with bradyarrhythmia and infiltration of the superior vena cava and right atrium. This case highlights an important consideration in type of pacemaker placement given the frequency of right atrial involvement in Erdheim-Chester disease. (Level of Difficulty: Advanced.)

We describe a case of a permanent pacemaker lead placement via the left pericardiophrenic vein for the treatment of tachy-brady syndrome due to a primary cardiac angiosarcoma. (Level of Difficulty: Advanced.)

We present the long-term follow-up of a 31-year-old woman who underwent cardioneuroablation (for atrioventricular (AV) block. Slow pathway ablation was performed in September 2017 with normal follow-up until April 2018, when the patient started noticing symptoms of palpitations at rest, and the electrocardiogram showed a Mobitz I AV block. A cardiac stress test and 24-h Holter monitoring demonstrated first- and second-degree block and normal AV conduction during times of higher heart rate. (Level of Difficulty: Advanced.)

Abstract Objectives Transcatheter aortic valve implantation is a recognized treatment for patients with severe aortic stenosis at all risk groups. However, permanent pacemaker rates remain high for self expandable transcatheter valves and permanent pacemaker implantation has been associated with increased morbidity. In this analysis we aim to evaluate short term clinical outcomes post self expandable transcatheter aortic valve implantation and determine risk factors for permanent pacemaker implantation. Methods 88 patients with severe aortic stenosis with transcatheter aortic valve implantation performed between the year 2016–2018 were retrospectively analyzed. Outcomes of interest included 1- year all cause mortality, 30-day major adverse cardiovascular events, permanent pacemaker and paravalvular leak rates. Survival analysis was performed with Kaplan Meier analysis and risk factors for survival and permanent pacemaker rates were identified with log rank test and regression analysis. Results The mean age of the cohort was 80.3 +/− 6.9 years. The mean STS score was 9.25. The 30 day all-cause mortality was 5.7% and 1-year all cause mortality was 16.7%. 80 patients had transfemoral transcatheter aortic valve implantation, and a majority of the patients (85.2%) were implanted with Corevalve Evolut R device. The device success rate was 88.6%. Multivariate analysis identified concomitant severe coronary artery disease (OR = 18.2 +/− 0.9; P = 0.002), pre transcatheter aortic valve implantation atrial fibrillation (OR = 8.6 +/− 0.91; P = 0.02) and post procedural disabling stroke (OR = 32.6 +/− 1.35; P = 0.01) as risk factors for 1-year mortality. The 30-day pacemaker rate was 17.6%. The presence of right bundle branch block (OR 11.1 +/− 0.86; P = 0.005), non-coronary cusp implantation depth (OR = 1.34 +/− 0.15; P = 0.05) and a non coronary cusp implantation depth / membranous septal length ratio of more than 50% were associated with post procedural pacemaker implantation (OR = 29.9 +/− 1.72; P = 0.05). Among the 15 patients with post procedural pacemaker implantation, 40% were found to be non-pacemaker dependent at 1 year. Conclusion Short term outcomes of transcatheter aortic valve implantation in severe aortic stenosis patients are promising. Pacemaker rates remain high. More studies are needed to evaluate the factors that influence pacemaker rates and dependence to further improve transcatheter aortic valve implantation outcomes.

Progressive conduction system disease affects patients with transthyretin cardiac amyloidosis, often requiring permanent pacing as the His-Purkinje system is affected. We present a case of left bundle branch pacing in a patient with transthyretin cardiac amyloidosis and infra-Hisian conduction disease with a favorable improvement in cardiac function and stable pacing thresholds. (Level of Difficulty: Intermediate.)

We report an unusual case of subacute right atrial perforation by a screw-in pacemaker lead that migrated into the right lung causing hemopneumothorax 2 weeks after the procedure. After transvenous simple manual traction and minithoracotomy repair of the right atrial wall, the lead was repositioned without any complications. (Level of Difficulty: Beginner.)

A woman with ischemic cardiomyopathy presented with recurrent syncope. Electrocardiogram showed complete heart block and torsade de pointes (TdP) secondary to amiodarone, recently started for paroxysmal atrial fibrillation. We describe a novel application of His bundle pacing that suppressed TdP and corrected the underlying left bundle branch block. (Level of Difficulty: Intermediate.)

Chest pain may be rarely associated with left bundle branch block (LBBB)-mediated ventricular dys-synchrony has been reported. This article reports 2 such cases, where left bundle branch area pacing resulted in resolution of the LBBB and associated symptoms. By adjusting the atrioventricular delays, the QRS duration was narrowed further by achieving fusion with the intrinsic activation wavefront. (Level of Difficulty: Beginner.)

We highlight a diagnostic challenge in a patient with dyspnea on exertion due to radiation therapy–induced severe first-degree atrioventricular block and how permanent His bundle pacing was helpful in overcoming these symptoms. (Level of Difficulty: Intermediate.)

Objective: The incidence of cardiac implantable electronic device (CIED) infection is usually