1
|
Bedford JP, Garside T, Darbyshire JL, Betts TR, Young JD, Watkinson PJ. Risk factors for new-onset atrial fibrillation during critical illness: A Delphi study. J Intensive Care Soc 2022; 23:414-424. [PMID: 36751347 PMCID: PMC9679893 DOI: 10.1177/17511437211022132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background New-onset atrial fibrillation (NOAF) is common during critical illness and is associated with poor outcomes. Many risk factors for NOAF during critical illness have been identified, overlapping with risk factors for atrial fibrillation in patients in community settings. To develop interventions to prevent NOAF during critical illness, modifiable risk factors must be identified. These have not been studied in detail and it is not clear which variables warrant further study. Methods We undertook an international three-round Delphi process using an expert panel to identify important predictors of NOAF risk during critical illness. Results Of 22 experts invited, 12 agreed to participate. Participants were located in Europe, North America and South America and shared 110 publications on the subject of atrial fibrillation. All 12 completed the three Delphi rounds. Potentially modifiable risk factors identified include 15 intervention-related variables. Conclusions We present the results of the first Delphi process to identify important predictors of NOAF risk during critical illness. These results support further research into modifiable risk factors including optimal plasma electrolyte concentrations, rates of change of these electrolytes, fluid balance, choice of vasoactive medications and the use of preventative medications in high-risk patients. We also hope our findings will aid the development of predictive models for NOAF.
Collapse
Affiliation(s)
- Jonathan P Bedford
- Nuffield Department of Clinical Neurosciences, University of
Oxford, Oxford, UK
| | - Tessa Garside
- Nuffield Department of Clinical Neurosciences, University of
Oxford, Oxford, UK
| | - Julie L Darbyshire
- Nuffield Department of Clinical Neurosciences, University of
Oxford, Oxford, UK
| | - Timothy R Betts
- Radcliffe Department of Medicine, University of Oxford, Oxford,
UK
| | - J Duncan Young
- Nuffield Department of Clinical Neurosciences, University of
Oxford, Oxford, UK
| | - Peter J Watkinson
- Nuffield Department of Clinical Neurosciences, University of
Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| |
Collapse
|
2
|
Liu W, Li S, Han B. It Is Necessary to Re-understand the Low-Voltage Area in Atrial Fibrillation Patients. Front Cardiovasc Med 2022; 9:919873. [PMID: 35783829 PMCID: PMC9247271 DOI: 10.3389/fcvm.2022.919873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/27/2022] [Indexed: 11/20/2022] Open
Abstract
The presence of a low-voltage areas (LVAs) is a major feature of the progression of atrial fibrillation. Typically, the LVA is determined by invasive left atrial voltage mapping. In addition to pulmonary vein electrical isolation, Voltage-guided substrate modification by targeting LVAs in addition to PVI has been shown to be superior to conventional PVI “only” approaches regarding freedom from AF recurrences after ablation. Recent studies have found Atrial wall thickness correlates with low voltage areas, and the degree of atrial myocardial fibrosis can be better assessed by CT or MRI in combination with voltage mapping, which might help reduce the recurrence of AF after catheter ablation.
Collapse
Affiliation(s)
- Wei Liu
- Bengbu Medical College, Bengbu, China
| | - Shijie Li
- Bengbu Medical College, Bengbu, China
- Department of Cardiology, Xuzhou Central Hospital, Xuzhou, China
- *Correspondence: Shijie Li
| | - Bing Han
- Department of Cardiology, Xuzhou Central Hospital, Xuzhou, China
| |
Collapse
|
3
|
Khakpour H, Hayase JH, Bradfield JS, Buch E, Shivkumar K. Atrial tachycardia arising from the distal left atrial appendage requiring high-power endocardial and epicardial ablation. HeartRhythm Case Rep 2021; 7:157-161. [PMID: 33786311 PMCID: PMC7987893 DOI: 10.1016/j.hrcr.2020.11.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Houman Khakpour
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Justin H Hayase
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Jason S Bradfield
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Eric Buch
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, California
| |
Collapse
|
4
|
Corrado C, Williams S, Roney C, Plank G, O'Neill M, Niederer S. Using machine learning to identify local cellular properties that support re-entrant activation in patient-specific models of atrial fibrillation. Europace 2021; 23:i12-i20. [PMID: 33437987 PMCID: PMC7943361 DOI: 10.1093/europace/euaa386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/15/2020] [Indexed: 11/17/2022] Open
Abstract
AIMS Atrial fibrillation (AF) is sustained by re-entrant activation patterns. Ablation strategies have been proposed that target regions of tissue that may support re-entrant activation patterns. We aimed to characterize the tissue properties associated with regions that tether re-entrant activation patterns in a validated virtual patient cohort. METHODS AND RESULTS Atrial fibrillation patient-specific models (seven paroxysmal and three persistent) were generated and validated against local activation time (LAT) measurements during an S1-S2 pacing protocol from the coronary sinus and high right atrium, respectively. Atrial models were stimulated with burst pacing from three locations in the proximity of each pulmonary vein to initiate re-entrant activation patterns. Five atria exhibited sustained activation patterns for at least 80 s. Models with short maximum action potential durations (APDs) were associated with sustained activation. Phase singularities were mapped across the atria sustained activation patterns. Regions with a low maximum conduction velocity (CV) were associated with tethering of phase singularities. A support vector machine (SVM) was trained on maximum local conduction velocity and action potential duration to identify regions that tether phase singularities. The SVM identified regions of tissue that could support tethering with 91% accuracy. This accuracy increased to 95% when the SVM was also trained on surface area. CONCLUSION In a virtual patient cohort, local tissue properties, that can be measured (CV) or estimated (APD; using effective refractory period as a surrogate) clinically, identified regions of tissue that tether phase singularities. Combing CV and APD with atrial surface area further improved the accuracy in identifying regions that tether phase singularities.
Collapse
Affiliation(s)
- Cesare Corrado
- Department of Biomedical Engineering, King's College London, 4th floor North Wing St Thomas' Hospital, Westminster Bridge Road, London SE17EH, UK
| | - Steven Williams
- Department of Biomedical Engineering, King's College London, 4th floor North Wing St Thomas' Hospital, Westminster Bridge Road, London SE17EH, UK
| | - Caroline Roney
- Department of Biomedical Engineering, King's College London, 4th floor North Wing St Thomas' Hospital, Westminster Bridge Road, London SE17EH, UK
| | - Gernot Plank
- Division of Biophysics, Medical University of Graz, Graz, Austria
| | - Mark O'Neill
- Department of Biomedical Engineering, King's College London, 4th floor North Wing St Thomas' Hospital, Westminster Bridge Road, London SE17EH, UK
| | - Steven Niederer
- Department of Biomedical Engineering, King's College London, 4th floor North Wing St Thomas' Hospital, Westminster Bridge Road, London SE17EH, UK
| |
Collapse
|
5
|
Mangiafico V, Saberwal B, Lavalle C, Raharja A, Ahmed Z, Papageorgiou N, Ahsan S. The role of CT in detecting AF substrate. Trends Cardiovasc Med 2020; 31:457-466. [PMID: 33068722 DOI: 10.1016/j.tcm.2020.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/29/2020] [Accepted: 10/10/2020] [Indexed: 10/23/2022]
Abstract
Despite technological advancements and evolving ablation strategies, atrial fibrillation catheter ablation outcome remains suboptimal for a cohort of patients. Imaging-based biomarkers have the potential to play a pivotal role in the overall assessment and prognostic stratification of AF patients, allowing for tailored treatments and individualized care. Alongside consolidated evaluation parameters, novel imaging biomarkers that can detect and stage the remodelling process and correlate it to electrophysiological phenomena are emerging. This review aims to provide a better understanding of the different types of atrial substrate, and how Computed Tomography can be used as a pre-ablation risk stratification tool by assessing the various novel imaging biomarkers, providing a valuable insight into the mechanisms that sustain AF and potentially allowing for a patient-specific ablation strategy.
Collapse
Affiliation(s)
- Valentina Mangiafico
- Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, "Sapienza" University of Rome, Policlinico Umberto I, Rome, Italy.
| | - Bunny Saberwal
- Barts Heart Centre, West Smithfield, London, EC1A 7BE, England.
| | - Carlo Lavalle
- Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric Sciences, "Sapienza" University of Rome, Policlinico Umberto I, Rome, Italy.
| | - Antony Raharja
- Barts Heart Centre, West Smithfield, London, EC1A 7BE, England.
| | - Zuhair Ahmed
- Queen Mary University of London, London, England.
| | | | - Syed Ahsan
- Barts Heart Centre, West Smithfield, London, EC1A 7BE, England.
| |
Collapse
|
6
|
van Staveren LN, de Groot NMS. Revealing hidden information from unipolar extracellular potentials. HeartRhythm Case Rep 2020; 6:942-946. [PMID: 33365245 PMCID: PMC7749207 DOI: 10.1016/j.hrcr.2020.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
7
|
Left atrial wall thickness is associated with the low-voltage area in patients with paroxysmal atrial fibrillation. J Interv Card Electrophysiol 2019; 58:315-321. [DOI: 10.1007/s10840-019-00611-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/06/2019] [Indexed: 12/23/2022]
|
8
|
Zuo K, Li K, Liu M, Li J, Liu X, Liu X, Zhong J, Yang X. Correlation of left atrial wall thickness and atrial remodeling in atrial fibrillation: Study based on low-dose-ibutilide-facilitated catheter ablation. Medicine (Baltimore) 2019; 98:e15170. [PMID: 30985700 PMCID: PMC6485781 DOI: 10.1097/md.0000000000015170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Atrial remodeling plays a significant role during the progression of atrial fibrillation (AF). Left atrial wall thickness (LAT) is a subjective and easily acquirable indicator referring to structural remodeling. Therefore, we aimed to investigate the association between LAT and atrial remodeling substrate, and to explore the predictive role of LAT about strong maintenance substrate and poor response to catheter ablation.LAT was measured by cardiac computed tomography in 2 selected locations (roof and floor) in 100 persistent AF patients. Then the low-dose-ibutilide-facilitated catheter ablation was performed and atrial maintenance substrate was categorized as weak, mild, and strong, based on the response to circumferential pulmonary vein isolation or complex fractionated atrial electrograms ablation. During follow-up, the success rate was evaluated. LAT showed a progressive thickening tendency from weak, mild, to strong maintenance substrate (roof: 2.2 mm vs. 2.6 mm vs. 3.9 mm, P < .0001; floor: 1.7 mm vs. 2.0 mm vs. 2.5 mm, P < .0001). During follow-up, the success rate of ablation was decreased with the maintenance substrate strengthening (weak 80%, mild 64.53%, strong 31.43%, P = .009). LA roof thickness >3.10 mm might be the predictor to strong atrial maintenance substrate and poor response to ablation.LAT was associated with the remodeling extent of atrial maintenance substrate and might predict the response to catheter ablation. These findings could help the clinicians to select the appropriate ablative strategy and predict the complexity and prognosis before catheter ablation.
Collapse
Affiliation(s)
- Kun Zuo
- Heart Center & Beijing Key Laboratory of Hypertension
| | - Kuibao Li
- Heart Center & Beijing Key Laboratory of Hypertension
| | - Min Liu
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Jing Li
- Heart Center & Beijing Key Laboratory of Hypertension
| | - Xiaoqing Liu
- Heart Center & Beijing Key Laboratory of Hypertension
| | - Xingpeng Liu
- Heart Center & Beijing Key Laboratory of Hypertension
| | | | - Xinchun Yang
- Heart Center & Beijing Key Laboratory of Hypertension
| |
Collapse
|
9
|
Rhee TM, Lee SR, Cha MJ, Choi EK, Oh S. Association of Complex Fractionated Electrograms with Atrial Myocardial Thickness and Fibrosis. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2018. [DOI: 10.18501/arrhythmia.2018.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
10
|
Song JS, Wi J, Lee HJ, Hwang M, Lim B, Kim TH, Uhm J, Joung B, Lee M, Seo JW, Pak HN. Role of atrial wall thickness in wave-dynamics of atrial fibrillation. PLoS One 2017; 12:e0182174. [PMID: 28827810 PMCID: PMC5565105 DOI: 10.1371/journal.pone.0182174] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/13/2017] [Indexed: 01/13/2023] Open
Abstract
Background/Aims Atrial anatomy and thickness may affect the electrical wave-dynamics of atrial fibrillation (AF). We explored the relationship between left atrial (LA) wall thickness (LAWT) or LA geometry and AF wave-dynamics. Methods We included 15 patients with persistent AF (age, 62.3 ± 11.9 years) who underwent AF catheter ablation. We measured the LAWT, LA endocardial curvature, and SD-curvature (surface bumpiness) from preprocedural computed tomography images. We compared those anatomical characteristics with electrophysiologic parameters such as dominant frequency (DF), Shannon entropy (ShEn), or complex fractionated atrial electrogram (CFAE)-cycle length (CL), calculated from intracardiac bipolar electrograms (300–500 points, 5 s), acquired during ablation procedures. Results 1. LAWT (excluding fat) varied widely among patients, locations, and types of AF. LAWT was inversely correlated with LA volume (r = -0.565, p = 0.028) and positively correlated with SD-curvature (r = 0.272, p < 0.001). 2. LAWT was positively correlated with ShEn (r = 0.233, p < 0.001) and negatively correlated with CFAE-CL (r = -0.107, p = 0.038). 3. In the multivariate linear regression analyses for AF wave-dynamics parameters, DF (β = -0.29 [95% CI -0.44–-0.14], p < 0.001), ShEn (β = 0.19 [95% CI 0.12–0.25], p < 0.001), and CFAE-CL (β = 7.49 [95% CI 0.65–14.34], p = 0.032) were independently associated with LAWT. Conclusion Regional LAWT is associated with LA structural features, and has significant correlations with the wave-dynamics parameters associated with electrical wavebreaks or rotors in patients with persistent AF.
Collapse
Affiliation(s)
- Jun-Seop Song
- Yonsei University Health System, Seoul, Republic of Korea
| | - Jin Wi
- Yonsei University Health System, Seoul, Republic of Korea
| | - Hye-Jeong Lee
- Yonsei University Health System, Seoul, Republic of Korea
| | - Minki Hwang
- Yonsei University Health System, Seoul, Republic of Korea
| | - Byounghyun Lim
- Yonsei University Health System, Seoul, Republic of Korea
| | - Tae-Hoon Kim
- Yonsei University Health System, Seoul, Republic of Korea
| | - Jae‐Sun Uhm
- Yonsei University Health System, Seoul, Republic of Korea
| | - Boyoung Joung
- Yonsei University Health System, Seoul, Republic of Korea
| | | | - Jeong-Wook Seo
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hui-Nam Pak
- Yonsei University Health System, Seoul, Republic of Korea
- * E-mail:
| |
Collapse
|
11
|
Varela M, Morgan R, Theron A, Dillon-Murphy D, Chubb H, Whitaker J, Henningsson M, Aljabar P, Schaeffter T, Kolbitsch C, Aslanidi OV. Novel MRI Technique Enables Non-Invasive Measurement of Atrial Wall Thickness. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:1607-1614. [PMID: 28422654 PMCID: PMC5549842 DOI: 10.1109/tmi.2017.2671839] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Knowledge of atrial wall thickness (AWT) has the potential to provide important information for patient stratification and the planning of interventions in atrial arrhythmias. To date, information about AWT has only been acquired in post-mortem or poor-contrast computed tomography (CT) studies, providing limited coverage and highly variable estimates of AWT. We present a novel contrast agent-free MRI sequence for imaging AWT and use it to create personalized AWT maps and a biatrial atlas. A novel black-blood phase-sensitive inversion recovery protocol was used to image ten volunteers and, as proof of concept, two atrial fibrillation patients. Both atria were manually segmented to create subject-specific AWT maps using an average of nearest neighbors approach. These were then registered non-linearly to generate an AWT atlas. AWT was 2.4 ± 0.7 and 2.7 ± 0.7 mm in the left and right atria, respectively, in good agreement with post-mortem and CT data, where available. AWT was 2.6 ± 0.7 mm in the left atrium of a patient without structural heart disease, similar to that of volunteers. In a patient with structural heart disease, the AWT was increased to 3.1 ± 1.3 mm. We successfully designed an MRI protocol to non-invasively measure AWT and create the first whole-atria AWT atlas. The atlas can be used as a reference to study alterations in thickness caused by atrial pathology. The protocol can be used to acquire personalized AWT maps in a clinical setting and assist in the treatment of atrial arrhythmias.
Collapse
|
12
|
Park J, Park CH, Uhm JS, Pak HN, Lee MH, Joung B. A Thin Left Atrial Antral Wall Around the Pulmonary Vein Reflects Structural Remodeling by Atrial Fibrillation and is Associated with Stroke. Yonsei Med J 2017; 58:282-289. [PMID: 28120557 PMCID: PMC5290006 DOI: 10.3349/ymj.2017.58.2.282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/20/2016] [Accepted: 09/29/2016] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Circumferential pulmonary (PV) vein isolation (CPVI) is the most important treatment strategy for atrial fibrillation (AF). While understanding left atrial wall thickness around PVs (PVWT) prior to catheter ablation is important, its clinical implications are not known. This study aimed to evaluate PVWT characteristics according to underlying disease and to identify associations between PVWT and reconnections of PV potentials (PVPs) in redo ablation. MATERIALS AND METHODS In 28 patients who underwent redo-AF ablation, PVWT and reconnected PVPs were evaluated at 12 sites (1-12 o'clock) around each PV. Clinical characteristics including stroke and CHA₂DS₂-VASc scores were analyzed according to the PVWT. RESULTS The PVWT was thicker in males than females (p<0.001) and in those with diabetes (p=0.045) or heart failure (p=0.002) than in those without. Patients with strokes or high CHA₂DS₂-VASc scores (≥3) had significantly thinner PVWTs than those without strokes or low CHA₂DS₂-VASc scores (p<0.001). In redo-ablation, reconnected PVPs were detected in 60 (53.6%) of 112 PVs, and the PVs were thicker (p<0.001) and had more reconnected PVs (p=0.009) than right PVs. A PVWT of >0.6 mm predicted PV reconnections with a sensitivity of 76.7% and specificity of 52.2% with an area under the curve of 0.695. CONCLUSION Thick PVWs were associated with diabetes and heart failure, and also showed significant inverse correlations with stroke and the CHA₂DS₂-VASc score. Thick PVWs were associated with reconnected PVPs after the CPVI, which were related to AF recurrence.
Collapse
Affiliation(s)
- Junbeom Park
- Department of Cardiology, School of Medicine, Ewha Womans University, Seoul, Korea
| | - Chul Hwan Park
- Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Sun Uhm
- Department of Cardiology, Yonsei University Health System, Seoul, Korea
| | - Hui Nam Pak
- Department of Cardiology, Yonsei University Health System, Seoul, Korea
| | - Moon Hyoung Lee
- Department of Cardiology, Yonsei University Health System, Seoul, Korea
| | - Boyoung Joung
- Department of Cardiology, Yonsei University Health System, Seoul, Korea.
| |
Collapse
|
13
|
State-of-the-Art CT Imaging of the Left Atrium. CURRENT RADIOLOGY REPORTS 2016. [DOI: 10.1007/s40134-016-0171-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Whitaker J, Rajani R, Chubb H, Gabrawi M, Varela M, Wright M, Niederer S, O'Neill MD. The role of myocardial wall thickness in atrial arrhythmogenesis. Europace 2016; 18:1758-1772. [PMID: 27247007 DOI: 10.1093/europace/euw014] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 01/13/2016] [Indexed: 01/08/2023] Open
Abstract
Changes in the structure and electrical behaviour of the left atrium are known to occur with conditions that predispose to atrial fibrillation (AF) and in response to prolonged periods of AF. We review the evidence that changes in myocardial thickness in the left atrium are an important part of this pathological remodelling process. Autopsy studies have demonstrated changes in the thickness of the atrial wall between patients with different clinical histories. Comparison of the reported tissue dimensions from pathological studies provides an indication of normal ranges for atrial wall thickness. Imaging studies, most commonly done using cardiac computed tomography, have demonstrated that these changes may be identified non-invasively. Experimental evidence using isolated tissue preparations, animal models of AF, and computer simulations proves that the three-dimensional tissue structure will be an important determinant of the electrical behaviour of atrial tissue. Accurately identifying the thickness of the atrial may have an important role in the non-invasive assessment of atrial structure. In combination with atrial tissue characterization, a comprehensive assessment of the atrial dimensions may allow prediction of atrial electrophysiological behaviour and in the future, guide radiofrequency delivery in regions based on their tissue thickness.
Collapse
Affiliation(s)
- John Whitaker
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - Ronak Rajani
- Department of Cardiac Computed Tomography, Cardiovascular Directorate, Guy's and St Thomas NHS Foundation Trust, London, UK
| | - Henry Chubb
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK.,Department of Paediatric Cardiology, Evelina London Children's Hospital, London, UK
| | - Mark Gabrawi
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - Marta Varela
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - Matthew Wright
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - Steven Niederer
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| | - Mark D O'Neill
- Electrophysiology Division of Cardiovascular Directorate and Division of Imaging Sciences and Biomedical Engineering, King's College London, 4th Floor, North Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK
| |
Collapse
|
15
|
Left atrial electrophysiologic feature specific for the genesis of complex fractionated atrial electrogram during atrial fibrillation. Heart Vessels 2015; 31:773-82. [PMID: 25854621 DOI: 10.1007/s00380-015-0672-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 04/01/2015] [Indexed: 10/23/2022]
Abstract
Complex fractionated atrial electrogram (CFAE) has been suggested to contribute to the maintenance of atrial fibrillation (AF). However, electrophysiologic characteristics of the left atrial myocardium responsible for genesis of CFAE have not been clarified. Non-contact mapping of the left atrium was performed at 37 AF onset episodes in 24 AF patients. Electrogram amplitude, width, and conduction velocity were measured during sinus rhythm, premature atrial contraction (PAC) with long- (L-PAC), short- (S-PAC) and very short-coupling intervals (VS-PAC). These parameters were compared between CFAE and non-CFAE regions. Unipolar electrogram amplitude was higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC (1.82 ± 0.73 vs. 1.13 ± 0.38, p < 0.001; 1.44 ± 0.54 vs. 0.92 ± 0.35, p < 0.001; 1.09 ± 0.40 vs. 0.70 ± 0.27, p < 0.001; 0.76 ± 0.30 vs. 0.53 ± 0.25 mV, p < 0.001). Laplacian bipolar electrogram amplitude was also higher in CFAE than non-CFAE during sinus rhythm, L-, S- and VS-PAC. Unipolar electrogram width was similar in CFAE and non-CFAE. Laplacian bipolar electrogram width was wider in CFAE than non-CFAE during L-, S- and VS-PAC (85.5 ± 6.8 vs. 79.6 ± 4.5, p < 0.001; 96.1 ± 9.7 vs. 84.5 ± 5.9, p < 0.001; 122.4 ± 16.0 vs. 99.6 ± 9.6 ms, p < 0.001), but not during sinus rhythm. The conduction velocity was slower in CFAE during sinus rhythm, L-, S- and VS-PAC than non-CFAE (1.7 ± 0.3 vs. 2.4 ± 0.4, p < 0.001; 1.4 ± 0.3 vs. 2.0 ± 0.5, p < 0.001; 1.2 ± 0.3 vs. 1.7 ± 0.5, p < 0.001; and 0.9 ± 0.3 vs. 1.4 ± 0.4 m/s, p < 0.001). CFAE was generated in the high amplitude atrial myocardium with slow and non-uniform conduction properties which were pronounced associated with premature activation, suggesting that heterogeneous conduction produced in high amplitude region contributes to the genesis of CFAE.
Collapse
|