1
|
Wilczek J, Jadczyk T, Wojakowski W, Gołba KS. Left ventricular electrical potential measured by the NOGA XP electromechanical mapping method as a predictor of response to cardiac resynchronization therapy. Front Cardiovasc Med 2023; 10:1107415. [PMID: 37215549 PMCID: PMC10193837 DOI: 10.3389/fcvm.2023.1107415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
Objectives The aim of the study was to determine whether left ventricular electrical potential measured by electromechanical mapping with the NOGA XP system has predictive value for response to CRT. Background Approximately 30% of patients who undergo cardiac resynchronization therapy do not see the expected effects. Methods The group of 38 patients qualified for CRT implantation were included in the study, of which 33 patients were analyzed. A 15% reduction in ESV after 6 months of pacing was used as a criterion for a positive response to CRT. The mean value and sum of unipolar and bipolar potentials obtained by mapping with the NOGA XP system and their predictive value in relation to the effect of CRT were analyzed using a bulls-eye projection at three levels: 1) the global value of the left ventricular (LV) potentials, 2) the potentials of the individual LV walls and 3) the mean value of the potentials of the individual segments (basal and middle) of the individual LV walls. Results 24 patients met the criterion of a positive response to CRT vs. 9 non-responders. At the global analysis stage, the independent predictors of favorable response to CRT were the sum of the unipolar potential and bipolar mean potential. In the analysis of individual left ventricular walls, the mean bipolar potential of the anterior and posterior wall and in the unipolar system, mean septal potential was found to be an independent predictor of favorable response to CRT. In the detailed segmental analysis, the independent predictors were the bipolar potential of the mid-posterior wall segment and the basal anterior wall segment. Conclusions Measurement of bipolar and unipolar electrical potentials with the NOGA XP system is a valuable method for predicting a favorable response to CRT.
Collapse
Affiliation(s)
- Jacek Wilczek
- Department of Electrocardiology and Heart Failure, Medical University of Silesia, Katowice, Poland
- Electrocardiology Department, Upper Silesian Medical Center, Katowice, Poland
| | - Tomasz Jadczyk
- Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
- Interventional Cardiac Electrophysiology Group, International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic
| | - Wojciech Wojakowski
- Division of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
- Third Department of Cardiology, Upper Silesian Medical Center, Katowice, Poland
| | - Krzysztof S. Gołba
- Department of Electrocardiology and Heart Failure, Medical University of Silesia, Katowice, Poland
- Electrocardiology Department, Upper Silesian Medical Center, Katowice, Poland
| |
Collapse
|
2
|
Omar AMS, Botero DMR, Caraballo JA, Kim GH, Khachatoorian Y, Kliewer J, Rahman MAA, Rifaie O, Bella JN, Argulian E, Contreras J. Tissue Doppler derived biphasic velocities during the pre and post-ejection phases: patterns, concordance and hemodynamic significance in health and disease. Cardiovasc Ultrasound 2022; 20:17. [PMID: 35836184 PMCID: PMC9281174 DOI: 10.1186/s12947-022-00287-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 06/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pre-(PRE) and post-ejection (POE) velocities by mitral annular tissue Doppler (TD) are biphasic and may be related to myocardial deformations. We investigated the predominance and concordance of TD-PRE and POE velocities and their effect on myocardial functions in controls and in heart failure (HF) patients. METHODS Retrospectively, 84 HF patients [57.6 years, 28(33%) females, NYHA: 2.3 ± 0.6, EF: 55 ± 15%, 52(62%) preserved EF, and 32(38%) reduced EF], 42 normal young controls, and 26 asymptomatic age matched controls were included. Echocardiography was done and from mitral annular tissue Doppler recordings, the biphasic PRE and POE velocity signals were identified and compared between groups. RESULTS While controls had almost always predominantly positive PRE and negative POE, HF had more negative PRE and positive POE. Moreover, almost all controls exhibited normal concordance (positive PRE and negative POE). HF exhibited more abnormal concordance which was significantly associated with worse NYHA, and parameters of diastolic and systolic functions. Opposite PRE and POE velocities correlated significantly in all groups (PREp vs POEn: young:r = 0.52, p < 0.001, age controls:r = 0.79, p < 0.001, HFpEF: r = 0.56, p < 0.001, HFrEF: r = 0.42, p = 0.018; PREn vs POEp: young: r = 0.25,p = 0.1, age controls: r = 0.42, p = 0.04, HFpEF: r = 0.43, p = 0.004, HFrEF: r = 0.61, p < 0.001) and the ratios PRE-P/N and POE-N/P correlated significantly with E/e' in HF only. CONCLUSIONS In physiological state, TD signals are predominantly positive during PRE and negative during POE. Opposite PRE and POE velocities corelate, representing the PRE-generation and POE-reversal of shortening-stretch relationships, the attenuation of which in HF may be related to elevated LV filling pressures. In HF, partially or completely reversed concordance of PRE and POE is associated with progressive worsening of clinical and hemodynamic profiles.
Collapse
Affiliation(s)
- Alaa Mabrouk Salem Omar
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA. .,Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Department of Internal Medicine, BronxCare Hospital Center, Bronx, NY, USA.
| | | | - Javier Arreaza Caraballo
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA
| | - Ga Hee Kim
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA
| | - Yeraz Khachatoorian
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA
| | - Jaclyn Kliewer
- Department of Internal Medicine, BronxCare Hospital Center, Bronx, NY, USA.,Department of General Surgery, HCA Florida Kendall Hospital, Miami, Florida, USA
| | | | - Osama Rifaie
- Depratment of Cardiology, Ain Shams University Hospital, Cairo, Egypt
| | - Jonathan N Bella
- Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Internal Medicine, BronxCare Hospital Center, Bronx, NY, USA
| | - Edgar Argulian
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA.,Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Johanna Contreras
- Department of Cardiology, Mount Sinai Morningside, 1111 Amsterdam avenue, NY, 10025, New York, USA.,Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| |
Collapse
|
3
|
Rijks J, Luermans J, Heckman L, van Stipdonk AMW, Prinzen F, Lumens J, Vernooy K. Physiology of Left Ventricular Septal Pacing and Left Bundle Branch Pacing. Card Electrophysiol Clin 2022; 14:181-189. [PMID: 35715076 DOI: 10.1016/j.ccep.2021.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Following the recognition of the adverse effects of right ventricular pacing, alternative permanent pacing strategies aiming to maintain a synchronous ventricular contraction have been sought. The quest for the optimal pacing site has recently led to several promising and rapidly emerging new pacing strategies, such as left ventricular septal pacing and left bundle branch pacing. In both animal and human studies, these pacing strategies seem to maintain electrical and mechanical activation of the left ventricle to a (near)physiologic level. However, more studies on the long-term effects of both strategies are needed.
Collapse
Affiliation(s)
- Jesse Rijks
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre (MUMC+), the Netherlands
| | - Justin Luermans
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre (MUMC+), the Netherlands; Department of Cardiology, Radboud University Medical Centre (RadboudUMC), Nijmegen, the Netherlands
| | - Luuk Heckman
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, the Netherlands
| | - Antonius M W van Stipdonk
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre (MUMC+), the Netherlands
| | - Frits Prinzen
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, the Netherlands
| | - Joost Lumens
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, the Netherlands
| | - Kevin Vernooy
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre (MUMC+), the Netherlands; Department of Cardiology, Radboud University Medical Centre (RadboudUMC), Nijmegen, the Netherlands.
| |
Collapse
|
4
|
Mora V, Roldán I, Romero E, Saurí A, Romero D, Pérez-Gozalbo J, Ugalde N, Bertolín J, Rodriguez-Israel M, Delgado CPO, Lowenstein JA. Myocardial Contraction during the Diastolic Isovolumetric Period: Analysis of Longitudinal Strain by Means of Speckle Tracking Echocardiography. J Cardiovasc Dev Dis 2018; 5:E41. [PMID: 30096870 PMCID: PMC6162423 DOI: 10.3390/jcdd5030041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/02/2018] [Accepted: 08/04/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND According to the ventricular myocardial band model, the diastolic isovolumetric period is a contraction phenomenon. Our objective was to employ speckle-tracking echocardiography (STE) to analyze myocardial deformation of the left ventricle (LV) and to confirm if it supports the myocardial band model. METHODS This was a prospective observational study in which 90 healthy volunteers were recruited. We evaluated different types of postsystolic shortening (PSS) from an LV longitudinal strain study. Duration of latest deformation (LD) was calculated as the time from the start of the QRS complex of the ECG to the latest longitudinal deformation peak in the 18 segments of the LV. RESULTS The mean age of our subjects was 50.3 ± 11.1 years. PSS was observed in 48.4% of the 1620 LV segments studied (19.8%, 13.5%, and 15.1% in the basal, medial, and apical regions, respectively). PSS was more frequent in the basal, medial septal, and apical anteroseptal segments (>50%). LD peaked in the interventricular septum and in the basal segments of the LV. CONCLUSIONS The pattern of PSS and LD revealed by STE suggests there is contraction in the postsystolic phase of the cardiac cycle. The anatomical location of the segments in which this contraction is most frequently observed corresponds to the main path of the ascending component of the myocardial band. This contraction can be attributed to the protodiastolic untwisting of the LV.
Collapse
Affiliation(s)
- Vicente Mora
- Department of Cardiology, Hospital Dr Peset, 46017 Valencia, Spain.
| | - Ildefonso Roldán
- Department of Cardiology, Hospital Dr Peset, 46017 Valencia, Spain.
| | - Elena Romero
- Department of Cardiology, Hospital Dr Peset, 46017 Valencia, Spain.
| | - Assumpció Saurí
- Department of Cardiology, Hospital Dr Peset, 46017 Valencia, Spain.
| | - Diana Romero
- Cardiodiagnosis Department, Medical Research of Buenos Aires, CP 1425 Buenos Aires, Argentina.
| | | | - Natalia Ugalde
- Cardiodiagnosis Department, Medical Research of Buenos Aires, CP 1425 Buenos Aires, Argentina.
| | - Javier Bertolín
- Department of Cardiology, Hospital Dr Peset, 46017 Valencia, Spain.
| | - Melisa Rodriguez-Israel
- Cardiodiagnosis Department, Medical Research of Buenos Aires, CP 1425 Buenos Aires, Argentina.
| | | | - Jorge A Lowenstein
- Cardiodiagnosis Department, Medical Research of Buenos Aires, CP 1425 Buenos Aires, Argentina.
| |
Collapse
|
5
|
Khokhlova A, Balakina-Vikulova N, Katsnelson L, Solovyova O. Effects of cellular electromechanical coupling on functional heterogeneity in a one-dimensional tissue model of the myocardium. Comput Biol Med 2017; 84:147-155. [PMID: 28364644 DOI: 10.1016/j.compbiomed.2017.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/28/2017] [Accepted: 03/21/2017] [Indexed: 11/25/2022]
Abstract
Based on the experimental evidence, we developed a one-dimensional (1D) model of heterogeneous myocardial tissue consisting of in-series connected cardiomyocytes from distant transmural regions using mathematical models of subendocardial and subepicardial cells. The regional deformation patterns produced by our 1D model are consistent with the transmural regional strain patterns obtained experimentally in the normal heart in vivo. The modelling results suggest that the mechanical load may essentially affect the transmural gradients in the electrical and mechanical properties of interacting myocytes within a tissue, thereby regulating global myocardial output.
Collapse
Affiliation(s)
- Anastasia Khokhlova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia.
| | - Nathalie Balakina-Vikulova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
| | - Leonid Katsnelson
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
| | - Olga Solovyova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
| |
Collapse
|
6
|
Kurt M, Tanboga IH, Aksakal E. Two-Dimensional Strain Imaging: Basic principles and Technical Consideration. Eurasian J Med 2015; 46:126-30. [PMID: 25610311 DOI: 10.5152/eajm.2014.28] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022] Open
Abstract
Tissue Doppler Imaging (TDI) and TDI-derived strain provide considerably accurate information in the non-invasive assessment of local myocardial functions. Given its high temporal and spatial resolution, TDI allows assessment of local myocardial functions in each phase of cardiac cycle. However, the most important limitation of this method is its angle dependence. New techniques to measure myocardial deformation, such as speckle tracking echocardiography, overcome the angle-dependence limitation of TDI-derived strain. Moreover, these techniques provide more unique information about myocardial fiber orientation. This review examines the architectural structure and function of the myocardium and includes technical revisions of this information that will provide a basis for STE.
Collapse
Affiliation(s)
- Mustafa Kurt
- Department of Cardiology, Mustafa Kemal University Faculty of Medicine, Hatay, Turkey
| | | | - Enbiya Aksakal
- Department of Cardiology, Ataturk University Faculty of Medicine, Erzurum, Turkey
| |
Collapse
|
7
|
Le TB, Sotiropoulos F. Fluid-structure interaction of an aortic heart valve prosthesis driven by an animated anatomic left ventricle. JOURNAL OF COMPUTATIONAL PHYSICS 2013; 244:41-62. [PMID: 23729841 PMCID: PMC3667163 DOI: 10.1016/j.jcp.2012.08.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We develop a novel large-scale kinematic model for animating the left ventricle (LV) wall and use this model to drive the fluid-structure interaction (FSI) between the ensuing blood flow and a mechanical heart valve prosthesis implanted in the aortic position of an anatomic LV/aorta configuration. The kinematic model is of lumped type and employs a cell-based, FitzHugh-Nagumo framework to simulate the motion of the LV wall in response to an excitation wavefront propagating along the heart wall. The emerging large-scale LV wall motion exhibits complex contractile mechanisms that include contraction (twist) and expansion (untwist). The kinematic model is shown to yield global LV motion parameters that are well within the physiologic range throughout the cardiac cycle. The FSI between the leaflets of the mechanical heart valve and the blood flow driven by the dynamic LV wall motion and mitral inflow is simulated using the curvilinear immersed boundary (CURVIB) method [1, 2] implemented in conjunction with a domain decomposition approach. The computed results show that the simulated flow patterns are in good qualitative agreement with in vivo observations. The simulations also reveal complex kinematics of the valve leaflets, thus, underscoring the need for patient-specific simulations of heart valve prosthesis and other cardiac devices.
Collapse
Affiliation(s)
- Trung Bao Le
- Saint Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, 2 Third Ave SE, Minneapolis, MN 55414
| | | |
Collapse
|
8
|
Le TB, Sotiropoulos F. On the three-dimensional vortical structure of early diastolic flow in a patient-specific left ventricle. EUROPEAN JOURNAL OF MECHANICS. B, FLUIDS 2012; 35:20-24. [PMID: 22773898 PMCID: PMC3388554 DOI: 10.1016/j.euromechflu.2012.01.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We study the formation of the mitral vortex ring during early diastolic filling in a patient-specific left ventricle using direct numerical simulation. The geometry of the left ventricle is reconstructed from Magnetic Resonance Imaging (MRI). The heart wall motion is modeled by a cell-based activation methodology, which yields physiologic kinematics with heart rate equal to 52 beats per minute. We show that the structure of the mitral vortex ring consists of the main vortex ring and trailing vortex tubes, which originate at the heart wall. The trailing vortex tubes play an important role in exciting twisting circumferential instability modes of the mitral vortex ring. At the end of diastole, the vortex ring impinges on the wall and the intraventricular flow transitions to a weak turbulent state. Our results can be used to help interprete and analyze three-dimensional in-vivo flow measurements obtained with MRI.
Collapse
Affiliation(s)
- Trung Bao Le
- St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Fotis Sotiropoulos
- St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
- Corresponding author at: Saint Anthony Falls Lab., Dept. Civil Engineering, University of Minnesota, 2 Third Ave SE, Minneapolis, MN 55414. Tel: +1 612 624 2022
| |
Collapse
|
9
|
Kim KH, Rosen A, Bruneau BG, Hui CC, Backx PH. Iroquois homeodomain transcription factors in heart development and function. Circ Res 2012; 110:1513-24. [PMID: 22628575 DOI: 10.1161/circresaha.112.265041] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Numerous cardiac transcription factors play overlapping roles in both the specification and proliferation of the cardiac tissues and chambers during heart development. It has become increasingly apparent that cardiac transcription factors also play critical roles in the regulation of expression of many functional genes in the prenatal and postnatal hearts. Accordingly, mutations of cardiac transcription factors cannot only result in congenital heart defects but also alter heart function thereby predisposing to heart disease and cardiac arrhythmias. In this review, we summarize the roles of Iroquois homeobox (Irx) family of transcription factors in heart development and function. In all, 6 Irx genes are expressed with distinct and overlapping patterns in the mammalian heart. Studies in several animal models demonstrate that Irx genes are important for the establishment of ventricular chamber properties, the ventricular conduction system, as well as heterogeneity of the ventricular repolarization. The molecular mechanisms by which Irx proteins regulate gene expression and the clinical relevance of Irx functions in the heart are discussed.
Collapse
Affiliation(s)
- Kyoung-Han Kim
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | |
Collapse
|
10
|
Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence in canines and humans in vivo. J Biomech 2012; 45:856-64. [PMID: 22284425 DOI: 10.1016/j.jbiomech.2011.11.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2011] [Indexed: 11/22/2022]
Abstract
Cardiovascular diseases rank as America's primary killer, claiming the lives of over 41% of more than 2.4 million Americans. One of the main reasons for this high death toll is the severe lack of effective imaging techniques for screening, early detection and localization of an abnormality detected on the electrocardiogram (ECG). The two most widely used imaging techniques in the clinic are CT angiography and echocardiography with limitations in speed of application and reliability, respectively. It has been established that the mechanical and electrical properties of the myocardium change dramatically as a result of ischemia, infarction or arrhythmia; both at their onset and after survival. Despite these findings, no imaging technique currently exists that is routinely used in the clinic and can provide reliable, non-invasive, quantitative mapping of the regional, mechanical, and electrical function of the myocardium. Electromechanical Wave Imaging (EWI) is an ultrasound-based technique that utilizes the electromechanical coupling and its associated resulting strain to infer to the underlying electrical function of the myocardium. The methodology of EWI is first described and its fundamental performance is presented. Subsequent in vivo canine and human applications are provided that demonstrate the applicability of Electromechanical Wave Imaging in differentiating between sinus rhythm and induced pacing schemes as well as mapping arrhythmias. Preliminary validation with catheter mapping is also provided and transthoracic electromechanical mapping in all four chambers of the human heart is also presented demonstrating the potential of this novel methodology to noninvasively infer to both the normal and pathological electrical conduction of the heart.
Collapse
|
11
|
Desjardins CL, Chen Y, Coulton AT, Hoit BD, Yu X, Stelzer JE. Cardiac myosin binding protein C insufficiency leads to early onset of mechanical dysfunction. Circ Cardiovasc Imaging 2011; 5:127-36. [PMID: 22157650 DOI: 10.1161/circimaging.111.965772] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Decreased expression of cardiac myosin binding protein C (cMyBPC) as a result of genetic mutations may contribute to the development of hypertrophic cardiomyopathy (HCM); however, the mechanisms that link cMyBPC expression and HCM development, especially contractile dysfunction, remain unclear. METHODS AND RESULTS We evaluated cardiac mechanical function in vitro and in vivo in young mice (8-10 weeks of age) carrying no functional cMyBPC alleles (cMyBPC(-/-)) or 1 functional cMyBPC allele (cMyBPC(±)). Skinned myocardium isolated from cMyBPC(-/-) hearts displayed significant accelerations in stretch activation cross-bridge kinetics. Cardiac MRI studies revealed severely depressed in vivo left ventricular (LV) magnitude and rates of LV wall strain and torsion compared with wild-type (WT) mice. Heterozygous cMyBPC(±) hearts expressed 23±5% less cMyBPC than WT hearts but did not display overt hypertrophy. Skinned myocardium isolated from cMyBPC(±) hearts displayed small accelerations in the rate of stretch induced cross-bridge recruitment. MRI measurements revealed reductions in LV torsion and circumferential strain, as well reduced circumferential strain rates in early systole and diastole. CONCLUSIONS Modest decreases in cMyBPC expression in the mouse heart result in early-onset subtle changes in cross-bridge kinetics and in vivo LV mechanical function, which could contribute to the development of HCM later in life.
Collapse
Affiliation(s)
- Candida L Desjardins
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | | | | | |
Collapse
|
12
|
Vanderheyden M, Penicka M, Bartunek J. Cellular Electrophysiological Abnormalities in Dyssynchronous Hearts and During CRT. J Cardiovasc Transl Res 2011; 5:127-34. [DOI: 10.1007/s12265-011-9335-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 11/16/2011] [Indexed: 01/19/2023]
|
13
|
Provost J, Lee WN, Fujikura K, Konofagou EE. Imaging the electromechanical activity of the heart in vivo. Proc Natl Acad Sci U S A 2011; 108:8565-70. [PMID: 21571641 PMCID: PMC3102378 DOI: 10.1073/pnas.1011688108] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cardiac conduction abnormalities remain a major cause of death and disability worldwide. However, as of today, there is no standard clinical imaging modality that can noninvasively provide maps of the electrical activation. In this paper, electromechanical wave imaging (EWI), a novel ultrasound-based imaging method, is shown to be capable of mapping the electromechanics of all four cardiac chambers at high temporal and spatial resolutions and a precision previously unobtainable in a full cardiac view in both animals and humans. The transient deformations resulting from the electrical activation of the myocardium were mapped in 2D and combined in 3D biplane ventricular views. EWI maps were acquired during five distinct conduction configurations and were found to be closely correlated to the electrical activation sequences. EWI in humans was shown to be feasible and capable of depicting the normal electromechanical activation sequence of both atria and ventricles. This validation of EWI as a direct, noninvasive, and highly translational approach underlines its potential to serve as a unique imaging tool for the early detection, diagnosis, and treatment monitoring of arrhythmias through ultrasound-based mapping of the transmural electromechanical activation sequence reliably at the point of care, and in real time.
Collapse
Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
| | - Wei-Ning Lee
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
| | - Kana Fujikura
- Department of Radiology, Columbia University, New York, NY 10032
| | - Elisa E. Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
- Department of Radiology, Columbia University, New York, NY 10032
| |
Collapse
|
14
|
|
15
|
Chen Y, Somji A, Yu X, Stelzer JE. Altered in vivo left ventricular torsion and principal strains in hypothyroid rats. Am J Physiol Heart Circ Physiol 2010; 299:H1577-87. [PMID: 20729398 DOI: 10.1152/ajpheart.00406.2010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The twisting and untwisting motions of the left ventricle (LV) lead to efficient ejection of blood during systole and filling of the ventricle during diastole. Global LV mechanical performance is dependent on the contractile properties of cardiac myocytes; however, it is not known how changes in contractile protein expression affect the pattern and timing of LV rotation. At the myofilament level, contractile performance is largely dependent on the isoforms of myosin heavy chain (MHC) that are expressed. Therefore, in this study, we used MRI to examine the in vivo mechanical consequences of altered MHC isoform expression by comparing the contractile properties of hypothyroid rats, which expressed only the slow β-MHC isoform, and euthyroid rats, which predominantly expressed the fast α-MHC isoform. Unloaded shortening velocity (V(o)) and apparent rate constants of force development (k(tr)) were measured in the skinned ventricular myocardium isolated from euthyroid and hypothyroid hearts. Increased expression of β-MHC reduced LV torsion and fiber strain and delayed the development of peak torsion and strain during systole. Depressed in vivo mechanical performance in hypothyroid rats was related to slowed cross-bridge performance, as indicated by significantly slower V(o) and k(tr), compared with euthyroid rats. Dobutamine infusion in hypothyroid hearts produced smaller increases in torsion and strain and aberrant transmural torsion patterns, suggesting that the myocardial response to β-adrenergic stress is compromised. Thus, increased expression of β-MHC alters the pattern and decreases the magnitude of LV rotation, contributing to reduced mechanical performance during systole, especially in conditions of increased workload.
Collapse
Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | | | | | | |
Collapse
|
16
|
Provost J, Lee WN, Fujikura K, Konofagou EE. Electromechanical wave imaging of normal and ischemic hearts in vivo. IEEE TRANSACTIONS ON MEDICAL IMAGING 2010; 29:625-35. [PMID: 19709966 PMCID: PMC3093312 DOI: 10.1109/tmi.2009.2030186] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Electromechanical wave imaging (EWI) has recently been introduced as a noninvasive, ultrasound-based imaging modality, which could map the electrical activation of the heart in various echocardiographic planes in mice, dogs, and humans in vivo. By acquiring radio-frequency (RF) frames at very high frame rates (390-520 Hz), the onset of small, localized, transient deformations resulting from the electrical activation of the heart, i.e., generating the electromechanical wave (EMW), can be mapped. The correlation between the EMW and the electrical activation speed and pacing scheme has previously been reported. In this study, we pursue the development of EWI using both displacements and strains and analysis of the EMW properties in dogs in vivo for early detection of ischemia. EWI was performed in normal and ischemic open-chest dogs during sinus rhythm. Ischemia of increasing severity was obtained by gradually obstructing the left-anterior descending (LAD) coronary artery flow. We also introduce the novel method of motion-matching that achieves the reconstruction of the full EWI ciné-loop at very high frame rates even when the ECG may be irregular or unavailable. Incremental displacements were previously used by our group to map the EMW. This paper focuses on the associated incremental strains, which facilitate the interpretation of the EMW by relating it directly to contraction. Moreover, we define the onset of the EMW as the time, at which the incremental strains change sign after the onset of the QRS complex of the ECG. Based on this definition, isochronal representations of the EMW were generated using a semi-automated method. The isochronal representation of the EMW during sinus rhythm was reproducible and shown similar to electrical activation maps previously reported in the literature. After segmentation using a contour-tracking method, the two- and four-chamber views were imaged and displayed in bi-plane views, allowing a 3-D interpretation of the EMW. EWI was shown to be sensitive to the presence of intermediate ischemia. EWI localized the ischemic region when the LAD flow was obstructed at 60% and beyond and was capable of mapping the increase of the ischemic region size as the LAD occlusion level increased. In conclusion, the activation maps and wave patterns obtained with EWI were similar to the electrical equivalents previously reported in the literature. Moreover, EWI was found to be sensitive enough to detect and map intermediate ischemia. Those results indicate that EWI could be used to assess the conduction properties of the myocardium, and detect its ischemic onset and disease progression entirely noninvasively.
Collapse
Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Wei-Ning Lee
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Kana Fujikura
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Elisa E. Konofagou
- Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 USA
| |
Collapse
|
17
|
Abraham T, Kass D, Tonti G, Tomassoni GF, Abraham WT, Bax JJ, Marwick TH. Imaging Cardiac Resynchronization Therapy. JACC Cardiovasc Imaging 2009; 2:486-97. [DOI: 10.1016/j.jcmg.2009.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 12/30/2008] [Accepted: 01/09/2009] [Indexed: 10/20/2022]
|
18
|
Sengupta PP. Exploring Left Ventricular Isovolumic Shortening and Stretch Mechanics⁎⁎Editorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology. JACC Cardiovasc Imaging 2009; 2:212-5. [DOI: 10.1016/j.jcmg.2008.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
|