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An 80-years-old patient with permanent atrial fibrillation and symptomatic, paroxysmal atrioventricular blocks (AVBs) underwent leadless pacemaker (L-PM) implantation. Seven years after implantation, as a consequence of a progression of the AVB towards a persistent form, resulting in an increased need for pacing, he developed a pacing-induced cardiomyopathy. He then underwent a successful upgrade from L-PM to a transvenous pacemaker (T-PM) with left bundle branch area pacing (LBBAP). The L-PM did not interfere with the T-PM and was turned off and abandoned. One month after the upgrading the patient showed a significant improvement in cardiac function and functional capacity., (© 2024 Wiley Periodicals LLC.)

The leadless pacemaker is an emerging technology with high efficacy and reduced complications rates. However, due to its novel status, some pitfalls remain to be addressed. We report the case of a 91-year-old patient undergoing a Micra pacemaker implantation. During the procedure, the maneuvers required for the adequate deployment of the device led to damaging of the septal tricuspid leaflet, resulting in severe tricuspid regurgitation. This is a severe mechanical complication of the Micra implantation technique, not previously reported in literature. In light of the novelty of the leadless pacemaker, we should remain cautious with regards to potential unreported complications., (© 2021 Wiley Periodicals LLC.)

Three-dimensional (3D) reconstruction by means of electroanatomic mapping (EAM) systems, allows for the understanding of the mechanism of focal or re-entrant arrhythmic circuits, which can be identified by means of dynamic (activation and propagation) and static (voltage) color-coded maps. However, besides this conventional use, EAM may offer helpful anatomical and functional information for tissue characterisation in several clinical settings. Today, data regarding electromechanical myocardial viability, scar detection in ischaemic and nonischaemic cardiomyopathy and arrhythmogenic right ventricle dysplasia (ARVC/D) definition are mostly consolidated, while emerging results are becoming available in contexts such as Brugada syndrome and cardiac resynchronisation therapy (CRT) implant procedures. As part of an invasive procedure, EAM has not yet been widely adopted as a stand-alone tool in the diagnostic path. We aim to review the data in the current literature regarding the use of 3D EAM systems beyond the definition of arrhythmia., (© 2021 Wiley Periodicals LLC.)

There is limited known safety and efficacy of leadless pacemaker device use in patients with durable left ventricular assist devices (LVADs). We present a case of a pacemaker-dependent LVAD patient with infection of permanent transvenous pacemaker who underwent successful implantation of Micra transcatheter pacing system (Medtronic)., (© 2020 Wiley Periodicals LLC.)

The left ventricular summit (LVS) is a challenging location for catheter-based percutaneous ablation due to its anatomical location. There have been case reports of cryoablations performed in this region, but the technique may be underutilized when radiofrequency ablation fails. A 45-year-old male was found to have 25 000 premature ventricular contractions (PVCs) a day despite previous ablation and a reduced ejection fraction of 40% despite medical therapy. Coronary sinus epicardial mapping revealed the coronary sinus distal region generated activations earlier than the QRS onset by 28 ms. Two separate, 4-minute cryoablations were delivered that suppressed the PVCs within 5 seconds. Alternate energy modalities such as cryo may offer a safer and more viable approach for ablation of LVS in select patients., (© 2020 Wiley Periodicals LLC.)

Background: Consensus statements on lead extraction give consideration to open surgical removal in the setting of large vegetations, to mitigate the risk of massive embolism that may occur with percutaneous lead removal. Vacuum-assisted debulking (VD) of large vegetations as an adjunct to percutaneous lead extraction may provide an opportunity to mitigate these risks., Methods: We retrospectively identified all patients undergoing lead extraction at our institution for endovascular infection from 2012 to 2018 and stratified them into two groups based on presence of adjunctive VD (n = 6) or without VD (no-VD, n = 39). VD was performed with the AngioVac system (Angio-Dynamics, Latham, NY, USA)., Results: Across the cohort, mean age was 62 ± 15 years, ejection fraction was 41 ± 16%, and 39% had end-stage renal disease on dialysis. Defibrillator systems were present in 71%, and 22% had cardiac resynchronization devices. Mean duration of the oldest extracted lead was 6.3 ± 4.9 years. There were no significant differences in baseline covariates between groups. Those in the VD group were significantly less likely to have Staphylococcus aureus as a causative organism (P = .04). In the VD group, vegetations targeted for debulking ranged in size from 1.8 to 6 cm (longest dimension). There were no operative deaths or clinically evident embolic events in either group. The overall nonfatal complication rate in the VD group was higher (33.3% vs 2.3%, P = .043)., Conclusion: VD can be performed as an adjunct to percutaneous lead extraction with a reasonable safety profile. The relative safety and efficacy of this approach removal requires further study., (© 2019 Wiley Periodicals, Inc.)

A Medtronic MICRA transcatheter pacing system (Medtronic, Minneapolis, MN, USA) was implanted in an 86-year-old patient with sick sinus syndrome and left bundle branch block after transfemoral aortic valve implantation. During implantation she developed a persistent complete heart block due to manipulation with the large-bore delivery catheter. Two weeks later, acute pacemaker dysfunction occurred due to massive increase of pacing threshold and impedance without obvious pacemaker dislocation or myocardial perforation. Recurrent capture failure was seen with pacing output set at 5 V/1.0 ms. Hence, microdislocation or fixation of the tines in the right ventricular trabeculae has to be assumed., (© 2016 Wiley Periodicals, Inc.)

In this paper, we describe the anatomy and physiology of the His bundle and describe the mechanisms by which permanent His-bundle pacing can be accomplished., (© 2016 Wiley Periodicals, Inc.)

Right ventricular pacing can cause ventricular dyssynchrony and result in reduced left ventricular systolic function and heart failure. Permanent His bundle pacing is a more physiologic form of pacing, but can be technically challenging. In this article, we describe our technique for permanent His bundle pacing including special considerations and limitations associated with His bundle pacing., (© 2016 Wiley Periodicals, Inc.)

Background: To objectively assess the quality of information available on the World Wide Web on cardiac resynchronization therapy (CRT). Patients frequently search the internet regarding their healthcare issues. It has been shown that patients seeking information can help or hinder their healthcare outcomes depending on the quality of information consulted. On the internet, this information can be produced and published by anyone, resulting in the risk of patients accessing inaccurate and misleading information., Methods: The search term "Cardiac Resynchronisation Therapy" was entered into the three most popular search engines and the first 50 pages on each were pooled and analyzed, after excluding websites inappropriate for objective review. The "LIDA" instrument (a validated tool for assessing quality of healthcare information websites) was to generate scores on Accessibility, Reliability, and Usability. Readability was assessed using the Flesch Reading Ease Score (FRES)., Results: Of the 150 web-links, 41 sites met the eligibility criteria. The sites were assessed using the LIDA instrument and the FRES. A mean total LIDA score for all the websites assessed was 123.5 of a possible 165 (74.8%). The average Accessibility of the sites assessed was 50.1 of 60 (84.3%), on Usability 41.4 of 54 (76.6%), on Reliability 31.5 of 51 (61.7%), and 41.8 on FRES. There was a significant variability among sites and interestingly, there was no correlation between the sites' search engine ranking and their scores., Conclusion: This study has illustrated the variable quality of online material on the topic of CRT. Furthermore, there was also no apparent correlation between highly ranked, popular websites and their quality. Healthcare professionals should be encouraged to guide their patients toward the online material that contains reliable information., (© 2016 Wiley Periodicals, Inc.)

Background: High-sensitivity cardiac troponin assays have provided a significant contribution for the early diagnosis of cardiovascular events. However, elevated cardiac troponin levels may occur in other clinical situations as supraventricular tachyarrhythmias with concerns about the mechanism of this elevation., Objectives and Methods: The goal of this study was to describe the performance of high-sensitivity cardiac troponin T (hs-cTnT) assay in patients presenting to the emergency department with a primary diagnosis of supraventricular tachyarrhythmia and to evaluate its relation with cardiovascular events during follow-up., Results: One hundred patients were included; mean age was 64 ± 12 years and 59.8% were men. The most common arrhythmia at admission was atrial fibrillation (68%), followed by atrial flutter (16%) and reentrant tachycardia (16%). The results of the first determination of hs-cTnT were positive (>14 ng/L) in 44.2% of the patients and the second determination was positive in 50.7% of the cases. The variation between the first and the second troponin levels was 1 (0-5) ng/L, and was >7 ng/L in 24.6% of the cases, with a clear trend toward higher troponin values in reentrant tachycardias. Four events were reported at 30 days; in all the cases the patients had presented atrial fibrillation and there were no significant differences in hs-cTnT values., Conclusions: There are a significant number of patients with supraventricular tachyarrhythmias who present elevated hs-cTnT levels. The association of this elevation with cardiovascular events seems to be very low., (©2016 Wiley Periodicals, Inc.)

Background: The Micra® Transcatheter Pacing System (TPS; Medtronic Inc., Minneapolis, MN, USA) is a miniaturized single-chamber pacemaker system that is delivered via catheter through the femoral vein. In this study, the electrical performance was compared between the TPS and a traditional leaded pacemaker. In addition, the safety profile of the two systems was compared by thorough monitoring for a number of adverse events., Methods: The TPS was implanted in the right ventricular apex of 10 Yucatan mini pigs and a Medtronic single-lead pacemaker (SLP) was implanted in the right ventricular apex of another 10 pigs and connected to a traditional pacemaker. The electrical performance of all devices was monitored for 12 weeks. The safety profile of each system was characterized using x-ray, computed tomography, ultrasound, blood work, and necropsy to monitor for a variety of adverse events., Results: At implant the mean pacing thresholds were 0.58 ± 0.17 V @0.24 ms and 0.75 ± 0.29 V @0.21 ms for the TPS and the SLP respectively. After 12 weeks, mean thresholds were 0.94 ± 0.46 V and 1.85 ± 0.75 V (P < 0.0001). There were two pulmonary emboli that were small and past the tertiary branch, and one occurred in each arm. There were also two infections with one in each arm. There were no dislodgements (macro or micro), tissue injury, tamponade, or valve injury., Conclusions: Overall, despite the 10-fold size reduction of the Micra TPS, it appears to perform similarly and have a similar safety profile to a traditional pacemaker system., (© 2015 Medtronic PLC. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.)

Background: The flexible-tip irrigated ablation catheter Cool Flex™ (St. Jude Medical, St. Paul, MN, USA) was introduced to enhance cooling of the catheter-tissue interface and to conform to endocardial surface with better contact. Little is known about the performance of such catheter design compared to the widely used rigid-tip catheters., Methods: In a thigh muscle preparation, ablation using the flexible-tip and rigid-tip catheters was performed in seven pigs across a range of ablation settings and catheter orientation. Postprocedure, the thigh muscle was stained with 2,3,5-triphenyltetrazolium-chloride injected into the femoral artery. The muscle was excised, fixed with formalin, and examined grossly., Results: A total of 196 lesions (95 flexible tip, 101 rigid tip) were evaluated. The flexible-tip catheter was associated with enhanced cooling of catheter-tissue interface (31.1 ± 3.3°C vs 36.3 ± 3.7°C, P = 0.0001) in both perpendicular and nonperpendicular catheter orientations. This allowed more energy delivery (37.3 ± 8.9 W vs 33.7 ± 8.1 W, P = 0.004) to targeted tissue and resulted in larger lesions (median 194.7 [interquartile range: 113.1-333.8] mm(3) vs 170.9 [88.7-261.6] mm(3) , P = 0.03) than the rigid-tip catheter with larger maximum diameter (11.1 ± 2.6 mm vs 10.3 ± 2.1 mm, P = 0.03) and larger diameter at tissue surface (10.3 ± 2.4 mm vs 9.6 ± 1.7 mm, P = 0.01). Catheter orientation during ablation affected the efficiency of rigid-tip but not the flexible-tip catheter. The use of the flexible-tip catheter was associated with significantly less char formation on tissue (none vs 5.1% with rigid tip, P = 0.009)., Conclusion: The Cool Flex™ catheter performed better than a rigid-tip catheter with enhanced cooling, larger ablation lesions, and no charring of targeted tissue., (© 2015 Wiley Periodicals, Inc.)