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Larsen BS, Biering-Sørensen T, Olsen FJ. Ischemic stroke and the emerging role of left atrial function. Expert Rev Cardiovasc Ther 2024; 22:289-300. [PMID: 38943632 DOI: 10.1080/14779072.2024.2370814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 06/18/2024] [Indexed: 07/01/2024]
Abstract
INTRODUCTION Ischemic stroke is a leading cause of morbidity and mortality worldwide. Emerging evidence suggests that left atrial (LA) dysfunction could play a role in the pathophysiology of ischemic stroke, as a possible contributor and as a predictive biomarker. AREAS COVERED This narrative review details the intricate relationship between LA function, atrial fibrillation (AF), and ischemic stroke. We discuss imaging techniques used to assess LA function, the mechanisms by which impaired LA function may contribute to stroke, and its potential as a prognostic marker of stroke. EXPERT OPINION There is a lack of evidence-based treatments of LA dysfunction in both primary and secondary stroke prevention. This is partly due to the lack of a practical clinical definition and unanswered questions concerning the clinical implications of LA dysfunction in patients without AF. Until such questions are resolved, addressing well-known cardiovascular risk factors, like hypertension and obesity, should be prioritized for preventing AF and ischemic stroke. These risk factors are closely tied to atrial remodeling, emphasizing the importance of targeting primary modifiable factors for preventing future morbidity and mortality.
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Affiliation(s)
- Bjørn Strøier Larsen
- Department of Cardiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tor Biering-Sørensen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Hellerup, Denmark
| | - Flemming Javier Olsen
- Department of Cardiology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Hellerup, Denmark
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Pola K, Ashkir Z, Myerson S, Arheden H, Watkins H, Neubauer S, Arvidsson PM, Raman B. Flow inefficiencies in non-obstructive HCM revealed by kinetic energy and hemodynamic forces on 4D-flow CMR. EUROPEAN HEART JOURNAL. IMAGING METHODS AND PRACTICE 2024; 2:qyae074. [PMID: 39210991 PMCID: PMC11350944 DOI: 10.1093/ehjimp/qyae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/10/2024] [Indexed: 09/04/2024]
Abstract
Aims Patients with non-obstructive hypertrophic cardiomyopathy (HCM) exhibit myocardial changes which may cause flow inefficiencies not detectable on echocardiogram. We investigated whether left ventricular (LV) kinetic energy (KE) and hemodynamic forces (HDF) on 4D-flow cardiovascular magnetic resonance (CMR) can provide more sensitive measures of flow in non-obstructive HCM. Methods and results Ninety participants (70 with non-obstructive HCM and 20 healthy controls) underwent 4D-flow CMR. Patients were categorized as phenotype positive (P+) based on maximum wall thickness (MWT) ≥ 15 mm or ≥13 mm for familial HCM, or pre-hypertrophic sarcomeric variant carriers (P-). LV KE and HDF were computed from 4D-flow CMR. Stroke work was computed using a previously validated non-invasive method. P+ and P- patients and controls had comparable diastolic velocities and LV outflow gradients on echocardiography, LV ejection fraction, and stroke volume on CMR. P+ patients had greater stroke work than P- patients, higher systolic KE compared with controls (5.8 vs. 4.1 mJ, P = 0.0009), and higher late diastolic KE relative to P- patients and controls (2.6 vs. 1.4 vs. 1.9 mJ, P < 0.0001, respectively). MWT was associated with systolic KE (r = 0.5, P < 0.0001) and diastolic KE (r = 0.4, P = 0.005), which also correlated with stroke work. Systolic HDF ratio was increased in P+ patients compared with controls (1.0 vs. 0.8, P = 0.03) and correlated with MWT (r = 0.3, P = 0.004). Diastolic HDF was similar between groups. Sarcomeric variant status was not associated with KE or HDF. Conclusion Despite normal flow velocities on echocardiography, patients with non-obstructive HCM exhibited greater stroke work, systolic KE and HDF ratio, and late diastolic KE relative to controls. 4D-flow CMR provides more sensitive measures of haemodynamic inefficiencies in HCM, holding promise for clinical trials of novel therapies and clinical surveillance of non-obstructive HCM.
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Affiliation(s)
- K Pola
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lund University, Skåne University Hospital Lund, Department of Clinical Sciences Lund, Clinical Physiology, Lund, Sweden
| | - Z Ashkir
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - S Myerson
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - H Arheden
- Lund University, Skåne University Hospital Lund, Department of Clinical Sciences Lund, Clinical Physiology, Lund, Sweden
| | - H Watkins
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - S Neubauer
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - P M Arvidsson
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lund University, Skåne University Hospital Lund, Department of Clinical Sciences Lund, Clinical Physiology, Lund, Sweden
| | - B Raman
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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Meskin M, Starkey PA, Kaspersen AE, Ringgaard S, Sand SG, Nygaard JV, Jensen JA, Traberg MS, Johansen P. Investigating the importance of left atrial compliance on fluid dynamics in a novel mock circulatory loop. Sci Rep 2024; 14:1864. [PMID: 38253772 PMCID: PMC10803730 DOI: 10.1038/s41598-024-52327-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
The left atrium (LA) hemodynamic indices hold prognostic value in various cardiac diseases and disorders. To understand the mechanisms of these conditions and to assess the performance of cardiac devices and interventions, in vitro models can be used to replicate the complex physiological interplay between the pulmonary veins, LA, and left ventricle. In this study, a comprehensive and adaptable in vitro model was created. The model includes a flexible LA made from silicone and allows distinct control over the systolic and diastolic functions of both the LA and left ventricle. The LA was mechanically matched with porcine LAs through expansion tests. Fluid dynamic measures were validated against the literature and pulmonary venous flows recorded on five healthy individuals using magnetic resonance flow imaging. Furthermore, the fluid dynamic measures were also used to construct LA pressure-volume loops. The in vitro pressure and flow recordings expressed a high resemblance to physiological waveforms. By decreasing the compliance of the LA, the model behaved realistically, elevating the a- and v-wave peaks of the LA pressure from 12 to 19 mmHg and 22 to 26 mmHg, respectively, while reducing the S/D ratio of the pulmonary venous flowrate from 1.5 to 0.3. This model provides a realistic platform and framework for developing and evaluating left heart procedures and interventions.
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Affiliation(s)
- Masoud Meskin
- Cardiovascular Biomechanics Group, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | - Philip Alexander Starkey
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | | | | | - Signe Gram Sand
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark
| | - Jens Vinge Nygaard
- Biomechanics and Mechanobiology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Marie Sand Traberg
- Cardiovascular Biomechanics Group, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Peter Johansen
- Cardiovascular Experimental Laboratory, Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, 8200, Aarhus N, Denmark.
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