scholarly journals 536 Intraoperative predictors of long-term pacing threshold improvement in leadless pacemakers

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Gianfranco Mitacchione ◽  
Marco Schiavone ◽  
Gianmarco Arabia ◽  
Francesca Salghetti ◽  
Manuel Cerini ◽  
...  
Keyword(s):  
Wave Amplitude ◽  
Strong Stability ◽  
Electrical Parameters ◽  
Pacing Threshold ◽  
Cardiology Department ◽  
Acute Increase ◽  
R Wave Amplitude ◽  
Practical Implications

Abstract Aims Micra-VR transcatheter pacing system (TPS) has shown strong stability of electrical parameters over time. Nevertheless, a small percentage of patients develops high pacing threshold (PT) (>1 [email protected] ms) which can decrease the longevity of battery. Our study sought to investigate the intraoperative electrical parameters able to predict device electrical performances during the time. Methods and results Patients (pts) implanted with Micra-VR TPS from March 2018 to January 2021 were prospectively considered at the Cardiology Department of Spedali Civili Hospital (Brescia) and Luigi Sacco Hospital (Milan). R-wave sensing amplitude (mV), pacing impedance (Ohm), and PT ([email protected] ms) were recorded twice: upon Micra final positioning, and after removal of the delivery system. All pts received a follow-up visit at 1- and 12-month after discharge. Electrical parameters were recorded at each visit. A total of 93 pts underwent Micra-VR implantation were enrolled. When compared to the first assessment, R-wave amplitude increased of 19.1% at second control performed after 13 ± 4 min (+1.71 ± 0.2 mV, 95% CI: 1.4–2.02; P < 0.001). Conversely, PT significantly decreased of 22.1% at 12-month follow-up respect to baseline (−0.22 ± 0.03 V, 95% CI: −0.13 to − 0.31; P < 0.001) (Figure 1). Among patients with high PT, acute increase of R-wave sensing of 1.5 mV after 14 ± 4 min significantly predicted PT normalization (≤1 [email protected] ms) 12 months post-implant (R = 0.72, 95% CI: 0.13–0.33, P < 0.001) (Figure 2), with a sensitivity of 87.5% (95% CI: 0.61–0.98) and a specificity of 88.8% (95% CI: 0.51–0.99) (Figure 3). Conclusions A 1.5 mV increase in R-wave amplitude at implant time is predictive of PT normalization (<1.0 V/0.24 ms) at 12-month FU. This finding may have practical implications for device repositioning in case of HPT at implant. This parameter could be considered for acute device repositioning, particularly in HPT patients. 536 Figure

scholarly journals Leadless pacemakers: does location matter?

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
C Menexi ◽  
M Elrefai ◽  
M Abouelasaad ◽  
P Roberts
Keyword(s):  
Wave Amplitude ◽  
Outflow Tract ◽  
Electrical Performance ◽  
Implantation Site ◽  
Pacing Threshold ◽  
Significant Difference ◽  
The Impact ◽  
R Wave Amplitude

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Leadless pacemakers (LPs) provide a viable alternative for patients who have an indication for pacing where transvenous pacing is not desirable or possible. Registries have demonstrated stable performance associated with LPs. There is preference towards implanting LPs into the trabeculated septum rather than the apex or free wall. We report our experience with the impact of the implantation site on acute and long-term electrical performance of LPs. Methods We ran a retrospective analysis on the first 100 LPS implanted at our centre. Two independent observers reviewed the fluoroscopic images and post-implant chest x-rays to classify the LPs’ positions.  We obtained the recorded pacing threshold , R-wave amplitude and impedance of the devices at the time of implant and at the latest available routine device follow-up. We used one-way ANOVA testing to compare the acute and long-term electrical performance of the LPs between different implantation sites. Results We were able to classify the site of the LPs implants in a total of 90 patient. 84 Patients (60% male) 57.3± 22.16 years were included .23.8% of the patients presented with syncope.  Indications for pacing were symptomatic sinus node dysfunction (33.3%), high grade AV block (34.5%), bradyarrhythmia associated with atrial tachyarrhythmias (28.6%) and other indications (3.6%). We had a 100% successful implant rate, 85.7% required ≤2 attempts and 71.4% required one attempt. A total of 32 implants were in the apex (38.1%), 26 in mid-septum (30.9 %), 13 in the apical septum (15.5%), 12 on the septal aspect of the right ventricular inflow (14.3%) and 1 implant (1.2%) in the septum of the RV outflow tract. The follow up period of the 84 patients was 3.09 ± 1.97 years. 100% of the LPs had the pacing thresholds <2.0 V @0.24 ms at the time of implant. Pacing threshold, R-wave amplitude, and impedance averaged at 0.67 ± 0.41 V, 10.86 ± 5.41 mV, and 775 ± 193.28 Ohms respectively at the time of implantation and 0.66 ± 0.39 V, 14.08 ± 6.14 mV, and 564.29 ± 96.76 Ohms at the last device check. There was no statistically significant difference in either the pacing thresholds or the impedance between implant sites. Post hocTukey’s analysis (excluding the outflow tract case) demonstrated significant statistical difference in the R-wave amplitudes between implants at the apex and the mid-septum both at the time of implantation (12.9 ± 6.1 mV and 8.53 ± 2.84 mV; p = 0.0196) and at follow up (15.97 ± 5.35 mV and 11.52 ± 5.01 mV; p = 0.0415). There were no differences between other sites Conclusions Our analysis demonstrated that aside from the difference between the sensed R wave amplitudes between LPs implanted at the apex and those implanted at mid-septum , there was no statistically significant difference in the acute or the long term electrical performance of implanted LPs regardless of the implantation site. A limitation to our analysis is the relatively low number of LP implants included in our analysis. Abstract Figure. Mean of parameters by validated position

scholarly journals Preliminary study on left bundle branch area pacing in children：clinical observation of 12 cases

2021 ◽  
Author(s):  
Wenlong Dai ◽  
Baojing Guo ◽  
Chen Cheng Dai ◽  
Jian zeng Dong
Keyword(s):  
Cardiac Dysfunction ◽  
Pacing Threshold ◽  
Narrow Qrs ◽  
Qrs Duration ◽  
Preliminary Study ◽  
Right Ventricular Apical Pacing ◽  
R Wave Amplitude ◽  
Lead Dislodgement

Objective: To explore the safety and feasibility of left bundle branch area pacing (LBBAP) in children. Methods: This study observed 12 children attempted LBBAP from 2019 to 2021 in our department prospectively. Clinical data, pacing parameters, electrocardiograms, echocardiographic measurements and complications were recorded at implant and during follow-up. Results: The 12 patients aged between 3 and 14ys and weighted from 13 to 48kg. 11 patients were diagnosed with third-degree AVB and 1 patient (case 4) suffered from cardiac dysfunction due to right ventricular apical pacing (RVAP). LBBAP was successfully achieved in all patients with narrow QRS complexes. LVEF of case 4 recovered on the 3rd day after LBBAP. The median of LVEDD Z score of the 12 patients decreased from 1.75 to1.05 3 months after implantation (p<0.05). The median of paced QRS duration was 103ms. The median of pacing threshold, R-wave amplitude and impedance were 0.85V, 15mV and 717Ω respectively and remained stable during follow-up. No complications such as loss of capture, lead dislodgement or septal perforation occurred. Conclusions: LBBAP can be performed safely in children with narrow QRS duration and stable pacing parameters. Cardiac dysfunction caused by long-term RVAP can be corrected by LBBAP quickly.

Comparison of electrical characteristics between atrial and ventricular side His-bundle pacing in bradycardia patients

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
X Liu ◽  
M Gu ◽  
Y.R Hu ◽  
W Hua ◽  
S Zhang
Keyword(s):  
Wave Amplitude ◽  
Electrical Characteristics ◽  
Pacing Threshold ◽  
His Bundle ◽  
His Bundle Pacing ◽  
Tricuspid Valve Annulus ◽  
Echocardiographic Parameters ◽  
Pacing Lead ◽  
R Wave Amplitude

Abstract Background His-bundle pacing (HBP) is recognized as the most physiological way of pacing but with less study focused on electrical characteristics in different site. Purpose We aimed to evaluate the differences of pacing and echocardiographic parameters between atrial and ventricular side His-bundle pacing. Methods Patients who successfully underwent HBP implantation from September 2018 to August 2019 were retrospectively analyzed. All patients were assigned to atrial-side HBP (aHBP) group or ventricular-side HBP (vHBP) group according to the location of the His-bundle pacing lead, which was confirmed by two methods including postoperative echocardiography and visualization of tricuspid valve annulus (TVA). The pacing and echocardiographic parameters were compared between two groups during the procedure and at 3-month follow-up. Results A total of 71 bradycardia patients who successfully underwent HBP implantation and confirmed lead position were included. Among them, twenty-seven were assigned to aHBP group and the other 44 were assigned to vHBP group with no significant differences in baseline clinical characteristics between two groups. During the procedure, the proportion of selective HBP was significantly higher (77.8% vs. 11.4%; P&lt;0.01) and the intra-procedural HV intervals was significantly longer (50.85±6.53 ms vs. 42.95±6.02 ms, P&lt;0.01) in aHBP group than in vHBP group. The capture threshold in vHBP group was significantly lower than in aHBP group at implantation (0.92±0.22 V/1.0ms vs. 1.05±0.26 V/1.0ms, P=0.03) and remain significantly difference after 3-month follow-up (0.98±0.23 V/1.0ms vs. 1.15±0.44 V/1.0ms, P=0.03). The R-wave amplitude was significantly higher in vHBP group than in aHBP group at implantation (5.82±2.52 mV vs. 3.74±1.81 mV, P&lt;0.01), and these differences still persisted during follow-up (5.88±2.51 mV vs. 3.67±1.61 mV, P&lt;0.01). During 3-month follow-up, an increase in the capture threshold &gt;1 V/1.0ms was seen in 2 cases in aHBP group while all patients remained stable in vHBP group. One patient developed a pocket hematoma in aHBP group compared to none in vHBP group. None of deterioration of tricuspid regurgitation and other procedure-related complications were observed during 3-month follow-up. Conclusions Ventricular side His-bundle pacing can achieve favourable pacing parameters including a lower pacing threshold and a higher R-wave amplitude than atrial side His-bundle pacing, which may be an ideal pacing strategy for patients in need of ventricular pacing. Funding Acknowledgement Type of funding source: None

Electrical characteristics of pacing different portions of the His bundle in bradycardia patients

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii27-ii35
Author(s):  
Yiran Hu ◽  
Min Gu ◽  
Wei Hua ◽  
Hongxia Niu ◽  
Hui Li ◽  
...  
Keyword(s):  
Wave Amplitude ◽  
Electrical Characteristics ◽  
Normal Range ◽  
Tricuspid Valve Regurgitation ◽  
His Bundle ◽  
His Bundle Pacing ◽  
Pacing Mode ◽  
Echocardiographic Assessment ◽  
R Wave Amplitude

Abstract Aims His-bundle pacing (HBP) can be achieved in either atrial-side HBP (aHBP) or ventricular-side HBP (vHBP). The study compared the pacing parameters and electrophysiological characteristics between aHBP and vHBP in bradycardia patients. Methods and results Fifty patients undergoing HBP implantation assisted by visualization of the tricuspid valvular annulus (TVA) were enrolled. The HBP lead position was identified by TVA angiography. Twenty-five patients were assigned to undergo aHBP and compared with 25 patients who underwent vHBP primarily in a prospective and randomized fashion. Pacing parameters and echocardiography were routinely assessed at implant and 3-month follow-up. His-bundle pacing was successfully performed in 45 patients (90% success rate with 44.4% aHBP and 55.6% vHBP). The capture threshold was lower in vHBP than aHBP at implant (vHBP: 1.1 ± 0.5 vs. aHBP: 1.4 ± 0.4 V/1.0 ms, P = 0.014) and 3-month follow-up (vHBP: 0.8 ± 0.4 vs. aHBP: 1.7 ± 0.8 V/0.4 ms, P &lt; 0.001). The R-wave amplitude was higher in vHBP than in aHBP at implant (vHBP: 4.5 ± 1.4 vs. aHBP: 2.0 ± 0.8 mV, P &lt; 0.001) and at 3-month follow-up (vHBP: 4.4 ± 1.5 vs. aHBP: 1.8 ± 0.7 mV, P &lt; 0.001). No procedure-related complications and aggravation of tricuspid valve regurgitation were observed in most patients and echocardiographic assessment of cardiac function remained in the normal range in all patients during the follow-up. Conclusion This study demonstrates that vHBP features a low and stable pacing capture threshold and high R-wave amplitude, suggesting better pacing mode management and battery longevity can be achieved by HBP in the ventricular side.

scholarly journals Unpacking differences in psychological contracts of organizational and self-initiated expatriates

2017 ◽  
Vol 5 (1) ◽  
pp. 93-108 ◽  
Author(s):  
Kate Yue Zhang ◽  
Bart Rienties
Keyword(s):  
Focus Group ◽  
Psychological Contract ◽  
Psychological Contracts ◽  
Focus Group Interviews ◽  
Cultural Training ◽  
Content Type ◽  
Group Interviews ◽  
Practical Implications

Purpose Global staffing has remained a main focus within the field of international human resource management (IHRM) since the 1970s. However, research in the psychological contract (PC) of expatriates is limited. The purpose of this paper is to explore the differences in PC breach and violation for organisational expatriates and self-initiated expatriates (SIEs). Design/methodology/approach A survey questionnaire was developed covering 52 organisational expatriates and 119 SIEs from 35 countries/regions working in China. Four follow-up focus group interviews including four organisational expatriates and 12 SIEs were conducted to further explain the findings of the survey. Findings The findings indicate that organisational expatriates experience significantly lower levels of PC breach and violation than SIEs. Three broad thematic areas arose from the triangulation of focus group interviews, including uncertainties in functioning of contracts, differences in job securities and career development opportunities, and cultural differences. Practical implications Employers should give a comprehensive orientation and cultural training to meet the needs of SIEs. Moreover, long-term career advancement paths should also be provided to SIEs to alleviate their vulnerability and insecurities working abroad. Originality/value The study contributes to the scholarship of self-initiated expatriation and PCs and give implications to IHRM strategies.

scholarly journals Visualization and establishment of product design regulations as interactive modules

2015 ◽  
Vol 17 (1) ◽  
pp. 20-34
Author(s):  
Mikael Blomé
Keyword(s):  
Action Research ◽  
Production Process ◽  
Design Methodology ◽  
Research Approach ◽  
Content Type ◽  
Action Research Approach ◽  
Practical Implications ◽  
Different Levels

Purpose – This paper aims to explore the preferable manner for visualizing different product regulations to be used in the training of and communication between people working at different levels in the production process. Many organizations struggle to communicate important and compulsory regulations, but the intended users are often reluctant to use them. Design/methodology/approach – The study has an action research approach, and the visualized regulations were the result of a human-centered design process that considered aspects for successful organizational change. Findings – The action research approach proved to be a successful framework to design the transformation of well-constructed illustrations in interactive guides, communicate and convince managers and users of the potential of the concept, develop a number of different well-functioning guides and establish regulations with illustrative elements and interactivity in a long-term perspective of an organization. Research limitations/implications – Further research is needed to follow-up the usage of visualized regulations to clarify how communication and quality are supported in design and production processes. Practical implications – The study shows how different product regulations should be visualized and established in an organization, with a potential for further dissemination. It is likely that the approach to design and visualize regulations in this study can function in other branches. Originality/value – The study finds a preferable manner for visualizing different product regulations to be used in the training of and communication between people working at different levels in the production process.

scholarly journals Long term follow up of the f wave amplitude in chronic atrial fibrillation.

1989 ◽  
Vol 26 (5) ◽  
pp. 489-493
Author(s):  
Hirokazu Saitho ◽  
Hirotsugu Atarashi ◽  
Tadamichi Fujiwara ◽  
Hirokazu Hayakawa
Keyword(s):  
Atrial Fibrillation ◽  
Wave Amplitude ◽  
Chronic Atrial Fibrillation ◽  
Long Term Follow Up ◽  
F Wave
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