Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.05.007
Background
Left bundle branch area pacing includes left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP), which is effective in patients with dyssynchronous heart failure (DHF). However, the basic mechanisms are unknown.
Objectives
This study aimed to compare LBBP with LVSP and explore potential mechanisms underlying the better clinical outcomes of LBBP.
Methods
A total of 24 beagles were assigned to the following groups: 1) control group; 2) DHF group, left bundle branch ablation followed by 6 weeks of AOO pacing at 200 ppm; 3) LBBP group, DHF for 3 weeks followed by 3 weeks of DOO pacing at 200 ppm; and 4) LVSP with the same interventions in the LBBP group. Metrics of electrocardiogram, echocardiography, hemodynamics, and expression of left ventricular proteins were evaluated.
Results
Compared with LVSP, LBBP had better peak strain dispersion (44.67 ± 1.75 ms vs 55.50 ± 4.85 ms; P < 0.001) and hemodynamic effect (dP/dtmax improvement: 27.16% ± 7.79% vs 11.37% ± 4.73%; P < 0.001), whereas no significant differences in cardiac function were shown. The altered expressions of proteins in the lateral wall vs septum in the DHF group were partially reversed by LBBP and LVSP, which was associated with the contraction and adhesion process, separately.
Conclusions
The animal study demonstrated that LBBP offered better mechanical synchrony and improved hemodynamics than LVSP, which might be explained by the reversed expression of contraction proteins. These results supported the potential superiority of left bundle branch area pacing with the capture of the conduction system in DHF model.
{"title":"Left Bundle Branch Area Pacing With or Without Conduction System Capture in Heart Failure Models","authors":"","doi":"10.1016/j.jacep.2024.05.007","DOIUrl":"10.1016/j.jacep.2024.05.007","url":null,"abstract":"<div><h3>Background</h3><div>Left bundle branch area pacing includes left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP), which is effective in patients with dyssynchronous heart failure (DHF). However, the basic mechanisms are unknown.</div></div><div><h3>Objectives</h3><div>This study aimed to compare LBBP with LVSP and explore potential mechanisms underlying the better clinical outcomes of LBBP.</div></div><div><h3>Methods</h3><div><span>A total of 24 beagles<span> were assigned to the following groups: 1) control group; 2) DHF group, left bundle branch ablation followed by 6 weeks of AOO pacing at 200 ppm; 3) LBBP group, DHF for 3 weeks followed by 3 weeks of DOO pacing at 200 ppm; and 4) LVSP with the same interventions in the LBBP group. Metrics of electrocardiogram, echocardiography, </span></span>hemodynamics, and expression of left ventricular proteins were evaluated.</div></div><div><h3>Results</h3><div>Compared with LVSP, LBBP had better peak strain dispersion (44.67 ± 1.75 ms vs 55.50 ± 4.85 ms; <em>P <</em> 0.001) and hemodynamic effect (dP/dtmax improvement: 27.16% ± 7.79% vs 11.37% ± 4.73%; <em>P <</em> 0.001), whereas no significant differences in cardiac function were shown. The altered expressions of proteins in the lateral wall vs septum in the DHF group were partially reversed by LBBP and LVSP, which was associated with the contraction and adhesion process, separately.</div></div><div><h3>Conclusions</h3><div>The animal study demonstrated that LBBP offered better mechanical synchrony and improved hemodynamics than LVSP, which might be explained by the reversed expression of contraction proteins. These results supported the potential superiority of left bundle branch area pacing with the capture of the conduction system in DHF model.</div></div>","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2234-2246"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141544830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.06.018
Connor P. Oates MD , Karel T.N. Breeman MD , Marc A. Miller MD , Percy Boateng MD , Aarti Patil MD , Daniel R. Musikantow MD , Elbert Williams MD , Ismail El-Hamamsy MD , Morgan L. Montgomery MD , Benjamin S. Salter MD , Chartaroon Rimsukcharoenchai MD , Dimosthenis Pandis MD , Menachem M. Weiner MD , Srinivas R. Dukkipati MD , Anelechi Anyanwu MD , Vivek Y. Reddy MD , David H. Adams MD , Ahmed M. El-Eshmawi MD
Background
Intraoperative implantation of leadless cardiac pacemakers (LCPs) under direct visualization during cardiac surgery is a novel strategy to provide pacing to patients with an elevated risk of postoperative conduction disorders or with a preexisting pacing indication undergoing valve surgery.
Objectives
This study sought to evaluate the long-term safety and efficacy of intraoperative LCP implantation in 100 consecutive patients.
Methods
Retrospective single-center cohort study of consecutive patients (n = 100) who underwent intraoperative LCP implantation during valve surgery. Safety and efficacy were assessed at implantation and follow-up visits.
Results
A total of 100 patients (age 68 ± 13 years, 47% female) underwent intraoperative LCP implantation. The surgery involved the tricuspid valve in 99 patients (99%), including tricuspid valve repair in 59 (59%) and tricuspid valve replacement in 40 (40%). Most of the patients (78%) underwent multivalve surgery. The indication for LCP implantation was elevated risk of postoperative atrioventricular block in 54% and preexisting bradyarrhythmias in 46%. LCP implantation was successful in all patients. During a median of 10.6 months (IQR: 2.0-22.7 months) of follow-up, no device-related complications occurred. At 12-month follow-up, the pacing thresholds were acceptable (≤2.0 V at 0.24 milliseconds) in 95% of patients.
Conclusions
Intraoperative LCP implantation under direct visualization is a safe strategy to provide permanent pacing in patients undergoing valve surgery, with a postoperative electrical performance comparable to percutaneously placed LCPs.
{"title":"Long-Term Safety and Efficacy of Intraoperative Leadless Pacemaker Implantation During Valve Surgery","authors":"Connor P. Oates MD , Karel T.N. Breeman MD , Marc A. Miller MD , Percy Boateng MD , Aarti Patil MD , Daniel R. Musikantow MD , Elbert Williams MD , Ismail El-Hamamsy MD , Morgan L. Montgomery MD , Benjamin S. Salter MD , Chartaroon Rimsukcharoenchai MD , Dimosthenis Pandis MD , Menachem M. Weiner MD , Srinivas R. Dukkipati MD , Anelechi Anyanwu MD , Vivek Y. Reddy MD , David H. Adams MD , Ahmed M. El-Eshmawi MD","doi":"10.1016/j.jacep.2024.06.018","DOIUrl":"10.1016/j.jacep.2024.06.018","url":null,"abstract":"<div><h3>Background</h3><div>Intraoperative implantation of leadless cardiac pacemakers (LCPs) under direct visualization during cardiac surgery is a novel strategy to provide pacing to patients with an elevated risk of postoperative conduction disorders or with a preexisting pacing indication undergoing valve surgery.</div></div><div><h3>Objectives</h3><div>This study sought to evaluate the long-term safety and efficacy of intraoperative LCP implantation in 100 consecutive patients.</div></div><div><h3>Methods</h3><div>Retrospective single-center cohort study of consecutive patients (n = 100) who underwent intraoperative LCP implantation during valve surgery. Safety and efficacy were assessed at implantation and follow-up visits.</div></div><div><h3>Results</h3><div>A total of 100 patients (age 68 ± 13 years, 47% female) underwent intraoperative LCP implantation. The surgery involved the tricuspid valve in 99 patients (99%), including tricuspid valve repair in 59 (59%) and tricuspid valve replacement in 40 (40%). Most of the patients (78%) underwent multivalve surgery. The indication for LCP implantation was elevated risk of postoperative atrioventricular block in 54% and preexisting bradyarrhythmias in 46%. LCP implantation was successful in all patients. During a median of 10.6 months (IQR: 2.0-22.7 months) of follow-up, no device-related complications occurred. At 12-month follow-up, the pacing thresholds were acceptable (≤2.0 V at 0.24 milliseconds) in 95% of patients.</div></div><div><h3>Conclusions</h3><div>Intraoperative LCP implantation under direct visualization is a safe strategy to provide permanent pacing in patients undergoing valve surgery, with a postoperative electrical performance comparable to percutaneously placed LCPs.</div></div>","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2224-2233"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.09.014
Kenneth A Ellenbogen, Pranav Mankad
{"title":"Insights Into Left Bundle Branch Area Pacing: Important Lessons Learned.","authors":"Kenneth A Ellenbogen, Pranav Mankad","doi":"10.1016/j.jacep.2024.09.014","DOIUrl":"https://doi.org/10.1016/j.jacep.2024.09.014","url":null,"abstract":"","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142465616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.08.011
Mary Pelling MD, Michael S. Lloyd MD
{"title":"Successful Implantation of Defibrillator Leads for Left Bundle Branch Pacing","authors":"Mary Pelling MD, Michael S. Lloyd MD","doi":"10.1016/j.jacep.2024.08.011","DOIUrl":"10.1016/j.jacep.2024.08.011","url":null,"abstract":"","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2269-2270"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.07.006
Martin Aguilar MD, PhD , Laurent Macle MD , Sewanou H. Honfo PhD , Paul Khairy MD, PhD , Julia Cadrin-Tourigny MD, PhD , Marc W. Deyell MD, MSc , Nathaniel Hawkins MD , Richard G. Bennett BSc, MBChB, PhD , Jason G. Andrade MD
{"title":"Very Late Atrial Arrhythmia Recurrence After Initial Successful AF Ablation","authors":"Martin Aguilar MD, PhD , Laurent Macle MD , Sewanou H. Honfo PhD , Paul Khairy MD, PhD , Julia Cadrin-Tourigny MD, PhD , Marc W. Deyell MD, MSc , Nathaniel Hawkins MD , Richard G. Bennett BSc, MBChB, PhD , Jason G. Andrade MD","doi":"10.1016/j.jacep.2024.07.006","DOIUrl":"10.1016/j.jacep.2024.07.006","url":null,"abstract":"","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2274-2276"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142145661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.07.018
Aneesh V. Tolat MD
{"title":"Ventricular Pace Mapping and TR Fusion","authors":"Aneesh V. Tolat MD","doi":"10.1016/j.jacep.2024.07.018","DOIUrl":"10.1016/j.jacep.2024.07.018","url":null,"abstract":"","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2145-2147"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.06.016
Ashwin Bhaskaran MBBS, MSc , Tejas Deshmukh MBBS, MClinTRes , Richard Bennett MbChB, PhD , Samual Turnbull BSc , Timothy G. Campbell BSc, PhD , Yasuhito Kotake MD, PhD , Dinesh Selvakumar MBBS , Michael A. Barry BSc , Juntang Lu BVSc, BSc , Lachlan Pearson BSc, BVSc, PhD , Eddy Kizana MBBS, PhD , James J.H. Chong MBBS, PhD , Saurabh Kumar BSc(Med)/MBBS, PhD
Background
The evolution of myocardial scar and its arrhythmogenic potential postinfarct is incompletely understood.
Objectives
This study sought to investigate scar and border zone (BZ) channels evolution in an animal ischemia-reperfusion injury model using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).
Methods
Five swine underwent 90-minute balloon occlusion of the mid-left anterior descending artery, followed by LGE-CMR at day (d) 3, d30, and d58 postinfarct. Invasive electroanatomic mapping (EAM) was performed at 2 months. Topographical reconstructions of LGE-CMR were analyzed for left ventricular core and BZ scar, BZ channel geometry, and complexity, including transmurality, orientation, and number of entrances/exits.
Results
LVEF reduced from 48.0% ± 1.8% to 41.3% ± 2.3% postinfarct. Total scar mass reduced over time (P = 0.008), including BZ (P = 0.002) and core scar (P = 0.05). A total of 72 BZ channels were analyzed across all animals and timepoints. Channel length (P = 0.05) and complexity (P = 0.02) reduced progressively from d3 to d58. However, at d58, 64% of channels were newly formed and 36% were midmyocardial. Conserved channels were initially longer and more complex. All LGE-CMR channels colocalized to regions of maximal decrement on EAM, with significantly greater decrement (115 ± 31 ms vs 83 ± 29 ms; P < 0.001) and uncovering of split potentials (24.8% vs 2.6%; P < 0.001) within channels. In total, 3 of 5 animals had inducible VT and tended to have more channels with greater midmyocardial involvement and functional decrement than those without VT.
Conclusions
BZ channels form early postinfarct and demonstrate evolutionary complexity and functional conduction slowing on EAM, highlighting their arrhythmogenic potential. Some channels regress in complexity and length, but new channels form at 2 months’ postinfarct, which may be midmyocardial, reflecting an evolving, 3-dimensional substrate for VT. LGE-CMR may help identify BZ channels that may support VT early postinfarct and lead to sudden death.
{"title":"Evolution of Substrate for Ventricular Arrhythmias Early Postinfarction","authors":"Ashwin Bhaskaran MBBS, MSc , Tejas Deshmukh MBBS, MClinTRes , Richard Bennett MbChB, PhD , Samual Turnbull BSc , Timothy G. Campbell BSc, PhD , Yasuhito Kotake MD, PhD , Dinesh Selvakumar MBBS , Michael A. Barry BSc , Juntang Lu BVSc, BSc , Lachlan Pearson BSc, BVSc, PhD , Eddy Kizana MBBS, PhD , James J.H. Chong MBBS, PhD , Saurabh Kumar BSc(Med)/MBBS, PhD","doi":"10.1016/j.jacep.2024.06.016","DOIUrl":"10.1016/j.jacep.2024.06.016","url":null,"abstract":"<div><h3>Background</h3><div>The evolution of myocardial scar and its arrhythmogenic potential postinfarct is incompletely understood.</div></div><div><h3>Objectives</h3><div>This study sought to investigate scar and border zone (BZ) channels evolution in an animal ischemia-reperfusion injury model using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).</div></div><div><h3>Methods</h3><div>Five swine underwent 90-minute balloon occlusion of the mid-left anterior descending artery, followed by LGE-CMR at day (d) 3, d30, and d58 postinfarct. Invasive electroanatomic mapping (EAM) was performed at 2 months. Topographical reconstructions of LGE-CMR were analyzed for left ventricular core and BZ scar, BZ channel geometry, and complexity, including transmurality, orientation, and number of entrances/exits.</div></div><div><h3>Results</h3><div>LVEF reduced from 48.0% ± 1.8% to 41.3% ± 2.3% postinfarct. Total scar mass reduced over time <em>(P =</em> 0.008), including BZ <em>(P =</em> 0.002) and core scar <em>(P =</em> 0.05). A total of 72 BZ channels were analyzed across all animals and timepoints. Channel length <em>(P =</em> 0.05) and complexity <em>(P =</em> 0.02) reduced progressively from d3 to d58. However, at d58, 64% of channels were newly formed and 36% were midmyocardial. Conserved channels were initially longer and more complex. All LGE-CMR channels colocalized to regions of maximal decrement on EAM, with significantly greater decrement (115 ± 31 ms vs 83 ± 29 ms; <em>P</em> < 0.001) and uncovering of split potentials (24.8% vs 2.6%; <em>P</em> < 0.001) within channels. In total, 3 of 5 animals had inducible VT and tended to have more channels with greater midmyocardial involvement and functional decrement than those without VT.</div></div><div><h3>Conclusions</h3><div>BZ channels form early postinfarct and demonstrate evolutionary complexity and functional conduction slowing on EAM, highlighting their arrhythmogenic potential. Some channels regress in complexity and length, but new channels form at 2 months’ postinfarct, which may be midmyocardial, reflecting an evolving, 3-dimensional substrate for VT. LGE-CMR may help identify BZ channels that may support VT early postinfarct and lead to sudden death.</div></div>","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2158-2168"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141874814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.06.029
William H. Frick MD , Robert Herman MD , Frantisek Simancik , Philip L. Mar MD, PharmD
{"title":"First in Human","authors":"William H. Frick MD , Robert Herman MD , Frantisek Simancik , Philip L. Mar MD, PharmD","doi":"10.1016/j.jacep.2024.06.029","DOIUrl":"10.1016/j.jacep.2024.06.029","url":null,"abstract":"","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2297-2299"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.05.009
Pouria Shoureshi MD , Zain Ahmad BS , Rahul Myadam MD , Li Wang PhD , Brianna Rose BS , Jaime Balderas-Villalobos PhD , Juana Medina-Contreras PhD , Anindita Das PhD , Ilija Uzelac PhD , Karoly Kaszala MD, PhD , Kenneth A. Ellenbogen MD , Jose F. Huizar MD , Alex Y. Tan MD
Background
The significance of autonomic dysfunction in premature ventricular contraction–induced cardiomyopathy (PVC-CM) remain unknown.
Objectives
Utilizing a novel “dual stressor” provocative challenge combining exercise with premature ventricular contraction (PVCs), the authors characterized the functional and molecular mechanisms of cardiac autonomic (cardiac autonomic nervous system) remodeling in a PVC-CM animal model.
Methods
In 15 canines (8 experimental, 7 sham), we implanted pacemakers and neurotelemetry devices and subjected animals to 12 weeks of bigeminal PVCs to induce PVC-CM. Sympathetic nerve activity (SNA), vagal nerve activity (VNA), and heart rate were continuously recorded before, during, and after treadmill exercise challenge with and without PVCs, at baseline and after development of PVC-CM. Western blot and enzyme-linked immunosorbent assay were used to evaluate molecular markers of neural remodeling.
Results
Exercise triggered an increase in both SNA and VNA followed by late VNA withdrawal. With PVCs, the degree of exercise-induced SNA augmentation was magnified, whereas late VNA withdrawal became blunted. After PVC-CM development, SNA was increased at rest but failed to adequately augment during exercise, especially with PVCs, coupled with impaired VNA and heart rate recovery after exercise. In the remodeled cardiac autonomic nervous system, there was widespread sympathetic hyperinnervation and elevated transcardiac norepinephrine levels but unchanged parasympathetic innervation, indicating sympathetic overload. However, cardiac nerve growth factor was paradoxically downregulated, suggesting an antineurotrophic counteradaptive response to PVC-triggered sympathetic overload.
Conclusions
Sympathetic overload, sympathetic dysfunction, and parasympathetic dysfunction in PVC-CM are unmasked by combined exercise and PVC challenge. Reduced cardiac neurotrophic factor might underlie the mechanisms of this dysfunction. Neuromodulation therapies to restore autonomic function could constitute a novel therapeutic approach for PVC-CM.
背景：自主神经功能障碍在室性早搏诱发心肌病（PVC-CM）中的意义尚不清楚：自主神经功能障碍在室性早搏诱发心肌病（PVC-CM）中的意义尚不清楚：作者利用一种结合了运动和室性早搏（PVCs）的新型 "双重应激 "挑战，描述了PVC-CM动物模型中心脏自主神经（心脏自主神经系统）重塑的功能和分子机制：方法：我们在 15 只犬（8 只实验犬，7 只假犬）中植入了心脏起搏器和神经遥测装置，并让动物接受了 12 周的大椎穴 PVC，以诱导 PVC-CM。交感神经活动（SNA）、迷走神经活动（VNA）和心率在有PVC和无PVC的跑步机运动挑战之前、期间和之后、基线和PVC-CM发展之后被连续记录。用 Western 印迹和酶联免疫吸附试验评估神经重塑的分子标记物：结果：运动会引发 SNA 和 VNA 的增加，随后 VNA 会在后期消失。当出现 PVC 时，运动诱导的 SNA 增高程度被放大，而晚期 VNA 撤回则变得迟钝。PVC-CM发生后，SNA在静息时增加，但在运动时却不能充分增强，尤其是在发生PVC时，同时运动后VNA和心率恢复受损。在重塑的心脏自主神经系统中，存在广泛的交感神经过度支配和经心肌去甲肾上腺素水平升高，但副交感神经支配没有改变，这表明交感神经负荷过重。然而，心脏神经生长因子却自相矛盾地下调了，这表明对PVC触发的交感超负荷有一种抗神经营养的反适应反应：结论：PVC-CM中的交感神经超负荷、交感神经功能障碍和副交感神经功能障碍在运动和PVC联合挑战中被揭示出来。心脏神经营养因子的减少可能是导致这种功能障碍的机制之一。恢复自律神经功能的神经调节疗法可能是治疗PVC-CM的一种新方法。
{"title":"Functional-Molecular Mechanisms of Sympathetic-Parasympathetic Dysfunction in PVC-Induced Cardiomyopathy Revealed by Dual Stressor PVC-Exercise Challenge","authors":"Pouria Shoureshi MD , Zain Ahmad BS , Rahul Myadam MD , Li Wang PhD , Brianna Rose BS , Jaime Balderas-Villalobos PhD , Juana Medina-Contreras PhD , Anindita Das PhD , Ilija Uzelac PhD , Karoly Kaszala MD, PhD , Kenneth A. Ellenbogen MD , Jose F. Huizar MD , Alex Y. Tan MD","doi":"10.1016/j.jacep.2024.05.009","DOIUrl":"10.1016/j.jacep.2024.05.009","url":null,"abstract":"<div><h3>Background</h3><div>The significance of autonomic dysfunction<span> in premature ventricular contraction–induced cardiomyopathy (PVC-CM) remain unknown.</span></div></div><div><h3>Objectives</h3><div><span>Utilizing a novel “dual stressor” provocative challenge combining exercise with premature ventricular contraction (PVCs), the authors characterized the functional and molecular mechanisms of cardiac autonomic (cardiac autonomic nervous system) remodeling in a PVC-CM </span>animal model.</div></div><div><h3>Methods</h3><div><span>In 15 canines (8 experimental, 7 sham), we implanted pacemakers and neurotelemetry devices and subjected animals to 12 weeks of bigeminal PVCs to induce PVC-CM. Sympathetic nerve activity<span><span> (SNA), vagal nerve activity (VNA), and heart rate were continuously recorded before, during, and after </span>treadmill exercise challenge with and without PVCs, at baseline and after development of PVC-CM. </span></span>Western blot<span> and enzyme-linked immunosorbent assay were used to evaluate molecular markers of neural remodeling.</span></div></div><div><h3>Results</h3><div><span>Exercise triggered an increase in both SNA and VNA followed by late VNA withdrawal. With PVCs, the degree of exercise-induced SNA augmentation was magnified, whereas late VNA withdrawal became blunted. After PVC-CM development, SNA was increased at rest but failed to adequately augment during exercise, especially with PVCs, coupled with impaired VNA and heart rate recovery after exercise. In the remodeled cardiac autonomic nervous system, there was widespread sympathetic hyperinnervation and elevated transcardiac </span>norepinephrine<span><span> levels but unchanged parasympathetic innervation, indicating sympathetic overload. However, cardiac </span>nerve growth factor was paradoxically downregulated, suggesting an antineurotrophic counteradaptive response to PVC-triggered sympathetic overload.</span></div></div><div><h3>Conclusions</h3><div>Sympathetic overload, sympathetic dysfunction, and parasympathetic dysfunction in PVC-CM are unmasked by combined exercise and PVC challenge. Reduced cardiac neurotrophic factor<span> might underlie the mechanisms of this dysfunction. Neuromodulation<span> therapies to restore autonomic function could constitute a novel therapeutic approach for PVC-CM.</span></span></div></div>","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2169-2182"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jacep.2024.05.017
Geertruida Petronella Bijvoet MD, PhD , Ben J.M. Hermans PhD , Dominik Linz MD, PhD , Justin G.L.M. Luermans MD, PhD , Bart Maesen MD, PhD , Robin Nijveldt MD, PhD , Casper Mihl MD, PhD , Kevin Vernooy MD, PhD , Joachim E. Wildberger MD, PhD , Rob J. Holtackers PhD , Ulrich Schotten MD, PhD , Sevasti-Maria Chaldoupi MD, PhD
Background
Dark-blood late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has better correlation with bipolar voltage (BiV) to define ablation scar in the left atrium (LA) compared to conventional bright-blood LGE CMR.
Objectives
This study sought to determine the optimal signal intensity threshold of dark-blood LGE CMR to identify LA ablation scar.
Methods
In 54 patients scheduled for atrial fibrillation ablation, image intensity ratios (IIRs) were derived from preprocedural dark-blood LGE CMR. In 26 patients without previous ablation, the upper limit of normal was derived from the 95th and 98th percentiles of pooled IIR values. In 28 patients with previous atrial fibrillation ablation, BiV was compared with the corresponding IIR. Receiver-operating characteristics analyses were employed to determine the optimal IIR threshold (ie, the point with the smallest distance to the upper left corner of the receiver-operating characteristics) for LA ablation scar (BiV ≤0.15 mV).
Results
Upper limit of normal corresponded to IIR values 1.16 and 1.21, yielding low sensitivities of 0.32 and 0.09 to detect LA ablation scar. Receiver-operating characteristics analysis of IIR and BiV comparison achieved a median area under the curve of 0.77. Median optimal IIR threshold for LA ablation scar was 1.09, with an average sensitivity of 0.73, specificity of 0.75, and accuracy of 0.71. Median IIR thresholds of 1.00 and 1.10 corresponded to 80% sensitivity and 80% specificity, respectively. There was considerable interpatient variability: optimal IIR thresholds per patient ranged from 1.01 to 1.22.
Conclusions
The optimal IIR threshold to identify LA ablation scar by dark-blood LGE CMR is 1.09. Because of interpatient variability, the investigators recommend using a lower (1.00) and upper (1.10) threshold to prevent over- or underestimation of ablation scar.
{"title":"Optimal Threshold and Interpatient Variability in Left Atrial Ablation Scar Assessment by Dark-Blood LGE CMR","authors":"Geertruida Petronella Bijvoet MD, PhD , Ben J.M. Hermans PhD , Dominik Linz MD, PhD , Justin G.L.M. Luermans MD, PhD , Bart Maesen MD, PhD , Robin Nijveldt MD, PhD , Casper Mihl MD, PhD , Kevin Vernooy MD, PhD , Joachim E. Wildberger MD, PhD , Rob J. Holtackers PhD , Ulrich Schotten MD, PhD , Sevasti-Maria Chaldoupi MD, PhD","doi":"10.1016/j.jacep.2024.05.017","DOIUrl":"10.1016/j.jacep.2024.05.017","url":null,"abstract":"<div><h3>Background</h3><div>Dark-blood late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has better correlation with bipolar voltage (BiV) to define ablation scar in the left atrium (LA) compared to conventional bright-blood LGE CMR.</div></div><div><h3>Objectives</h3><div>This study sought to determine the optimal signal intensity threshold of dark-blood LGE CMR to identify LA ablation scar.</div></div><div><h3>Methods</h3><div>In 54 patients scheduled for atrial fibrillation ablation, image intensity ratios (IIRs) were derived from preprocedural dark-blood LGE CMR. In 26 patients without previous ablation, the upper limit of normal was derived from the 95th and 98th percentiles of pooled IIR values. In 28 patients with previous atrial fibrillation ablation, BiV was compared with the corresponding IIR. Receiver-operating characteristics analyses were employed to determine the optimal IIR threshold (ie, the point with the smallest distance to the upper left corner of the receiver-operating characteristics) for LA ablation scar (BiV ≤0.15 mV).</div></div><div><h3>Results</h3><div>Upper limit of normal corresponded to IIR values 1.16 and 1.21, yielding low sensitivities of 0.32 and 0.09 to detect LA ablation scar. Receiver-operating characteristics analysis of IIR and BiV comparison achieved a median area under the curve of 0.77. Median optimal IIR threshold for LA ablation scar was 1.09, with an average sensitivity of 0.73, specificity of 0.75, and accuracy of 0.71. Median IIR thresholds of 1.00 and 1.10 corresponded to 80% sensitivity and 80% specificity, respectively. There was considerable interpatient variability: optimal IIR thresholds per patient ranged from 1.01 to 1.22.</div></div><div><h3>Conclusions</h3><div>The optimal IIR threshold to identify LA ablation scar by dark-blood LGE CMR is 1.09. Because of interpatient variability, the investigators recommend using a lower (1.00) and upper (1.10) threshold to prevent over- or underestimation of ablation scar.</div></div>","PeriodicalId":14573,"journal":{"name":"JACC. Clinical electrophysiology","volume":"10 10","pages":"Pages 2186-2197"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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