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1.
Bioengineering (Basel) ; 11(7)2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39061817

RESUMEN

Three-dimensional echocardiography (3D ECHO) and magnetic resonance (MR) imaging are frequently used in patients and animals to evaluate heart functions. Inverse finite element (FE) modeling is increasingly applied to MR images to quantify left ventricular (LV) function and estimate myocardial contractility and other cardiac biomarkers. It remains unclear, however, as to whether myocardial contractility derived from the inverse FE model based on 3D ECHO images is comparable to that derived from MR images. To address this issue, we developed a subject-specific inverse FE model based on 3D ECHO and MR images acquired from seven healthy swine models to investigate if there are differences in myocardial contractility and LV geometrical features derived using these two imaging modalities. We showed that end-systolic and end-diastolic volumes derived from 3D ECHO images are comparable to those derived from MR images (R2=0.805 and 0.969, respectively). As a result, ejection fraction from 3D ECHO and MR images are linearly correlated (R2=0.977) with the limit of agreement (LOA) ranging from -17.95% to 45.89%. Using an inverse FE modeling to fit pressure and volume waveforms in subject-specific LV geometry reconstructed from 3D ECHO and MR images, we found that myocardial contractility derived from these two imaging modalities are linearly correlated with an R2 value of 0.989, a gradient of 0.895, and LOA ranging from -6.11% to 36.66%. This finding supports using 3D ECHO images in image-based inverse FE modeling to estimate myocardial contractility.

2.
Open Life Sci ; 19(1): 20220890, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38911926

RESUMEN

Adverse cardiac mechanical remodeling is critical for the progression of heart failure following myocardial infarction (MI). We previously demonstrated the involvement of RIP3-mediated necroptosis in the loss of functional cardiomyocytes and cardiac dysfunction post-MI. Herein, we investigated the role of RIP3 in NOD-like receptor protein 3 (NLRP3)-mediated inflammation and evaluated the effects of RIP3 knockdown on myocardial mechanics and functional changes after MI. Our findings revealed that mice with MI for 4 weeks exhibited impaired left ventricular (LV) myocardial mechanics, as evidenced by a significant decrease in strain and strain rate in each segment of the LV wall during both systole and diastole. However, RIP3 knockdown ameliorated cardiac dysfunction by improving LV myocardial mechanics not only in the anterior wall but also in other remote nonischemic segments of the LV wall. Mechanistically, knockdown of RIP3 effectively inhibited the activation of the nuclear factor kappa-B (NF-κB)/NLRP3 pathway, reduced the levels of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) in the heart tissues, and mitigated adverse cardiac remodeling following MI. These results suggest that downregulation of RIP3 holds promise for preventing myocardial inflammation and cardiac mechanical remodeling following MI by regulating the NF-κB/NLRP3 pathway.

3.
Comput Biol Med ; 141: 105050, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34823858

RESUMEN

Cardiac resynchronization therapy (CRT) is an established treatment for left bundle branch block (LBBB) resulting in mechanical dyssynchrony. Approximately 1/3 of patients with CRT, however, are non-responders. To understand factors affecting CRT response, an electromechanics-perfusion computational model based on animal-specific left ventricular (LV) geometry and coronary vascular networks located in the septum and LV free wall is developed. The model considers contractility-flow and preload-activation time relationships, and is calibrated to simultaneously match the experimental measurements in terms of the LV pressure, volume waveforms and total coronary flow in the left anterior descending and left circumflex territories from 2 swine models under right atrium and right ventricular pacing. The model is then applied to investigate the responses of CRT indexed by peak LV pressure and (dP/dt)max at multiple pacing sites with different degrees of perfusion in the LV free wall. Without the presence of ischemia, the model predicts that basal-lateral endocardial region is the optimal pacing site that can best improve (dP/dt)max by 20%, and is associated with the shortest activation time. In the presence of ischemia, a non-ischemic region becomes the optimal pacing site when coronary flow in the ischemic region fell below 30% of its original value. Pacing at the ischemic region produces little response at that perfusion level. The optimal pacing site is associated with one that optimizes the LV activation time. These findings suggest that CRT response is affected by both pacing site and coronary perfusion, which may have clinical implication in improving CRT responder rates.


Asunto(s)
Terapia de Resincronización Cardíaca , Insuficiencia Cardíaca , Animales , Bloqueo de Rama/terapia , Terapia de Resincronización Cardíaca/métodos , Simulación por Computador , Ventrículos Cardíacos , Humanos , Perfusión , Porcinos
4.
Exp Mech ; 61(1): 131-146, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33746236

RESUMEN

BACKGROUND: The mechanical stimulus (i.e. stress or stretch) for growth occurring in the pressure-overloaded left ventricle (LV) is not exactly known. OBJECTIVE: To address this issue, we investigate the correlation between local ventricular growth (indexed by local wall thickness) and the local acute changes in mechanical stimuli after aortic banding. METHODS: LV geometric data were extracted from 3D echo measurements at baseline and 2 weeks in the aortic banding swine model (n = 4). We developed and calibrated animal-specific finite element (FE) model of LV mechanics against pressure and volume waveforms measured at baseline. After the simulation of the acute effects of pressure-overload, the local changes of maximum, mean and minimum myocardial stretches and stresses in three orthogonal material directions (i.e., fiber, sheet and sheet-normal) over a cardiac cycle were quantified. Correlation between mechanical quantities and the corresponding measured local changes in wall thickness was quantified using the Pearson correlation number (PCN) and Spearman rank correlation number (SCN). RESULTS: At 2 weeks after banding, the average septum thickness decreased from 10.6 ± 2.92mm to 9.49 ± 2.02mm, whereas the LV free-wall thickness increased from 8.69 ± 1.64mm to 9.4 ± 1.22mm. The FE results show strong correlation of growth with the changes in maximum fiber stress (PCN = 0.5471, SCN = 0.5111) and changes in the mean sheet-normal stress (PCN= 0.5266, SCN = 0.5256). Myocardial stretches, however, do not have good correlation with growth. CONCLUSION: These results suggest that fiber stress is the mechanical stimuli for LV growth in pressure-overload.

5.
J Appl Physiol (1985) ; 128(5): 1106-1122, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32078466

RESUMEN

Cardiac-coronary interaction and the effects of its pathophysiological variations on spatial heterogeneity of coronary perfusion and myocardial work are still poorly understood. This hypothesis-generating study predicts spatial heterogeneities in both regional cardiac work and perfusion that offer a new paradigm on the vulnerability of the subendocardium to ischemia, particularly at the apex. We propose a mathematical and computational modeling framework to simulate the interaction of left ventricular mechanics, systemic circulation, and coronary microcirculation. The computational simulations revealed that the relaxation rate of the myocardium has a significant effect whereas the contractility has a marginal effect on both the magnitude and transmural distribution of coronary perfusion. The ratio of subendocardial to subepicardial perfusion density (Qendo/Qepi) changed by -12 to +6% from a baseline value of 1.16 when myocardial contractility was varied by +25 and -10%, respectively; Qendo/Qepi changed by 37% when sarcomere relaxation rate, b, was faster and increased by 10% from the baseline value. The model predicts axial differences in regional myocardial work and perfusion density across the wall thickness. Regional myofiber work done at the apex is 30-50% lower than at the center region, whereas perfusion density in the apex is lower by only 18% compared with the center. There are large axial differences in coronary flow and myocardial work at the subendocardial locations, with the highest differences located at the apex region. A mismatch exists between perfusion density and regional work done at the subendocardium. This mismatch is speculated to be compensated by coronary autoregulation.NEW & NOTEWORTHY We present a model of left ventricle perfusion based on an anatomically realistic coronary tree structure that includes its interaction with the systemic circulation. Left ventricular relaxation rate has a significant effect on the regional distribution of coronary flow and myocardial work.


Asunto(s)
Circulación Coronaria , Miocardio , Vasos Coronarios , Corazón , Perfusión
6.
Int J Numer Method Biomed Eng ; 36(3): e3313, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31955509

RESUMEN

Models of cardiac mechanics require a well-defined reference geometry from which deformations and hence myocardial strain and stress can be calculated. In the in vivo beating heart, the load-free (LF) geometry generally cannot be measured directly, since, in many cases, there is no stage at which the lumen pressures and contractile state are all zero. Therefore, there is a need for an efficient method to estimate the LF geometry, which is essential for an accurate mechanical simulation of left ventricular (LV) mechanics, and for estimations of passive and contractile constitutive parameters of the heart muscle. In this paper, we present a novel method for estimating both the LF geometry and the passive stiffness of the myocardium. A linear combination of principal components from a population of diastolic displacements is used to construct the LF geometry. For each estimate of the LF geometry and tissue stiffness, LV inflation is simulated, and the model predictions are compared with surface data at multiple stages during passive diastolic filling. The feasibility of this method was demonstrated using synthetically deformation data that were generated using LV models derived from clinical magnetic resonance image data, and the identifiability of the LF geometry and passive stiffness parameters were analysed using Hessian metrics. Applications of this method to clinical data would improve the accuracy of constitutive parameter estimation and allow a better simulation of LV wall strains and stresses.


Asunto(s)
Miocardio/patología , Análisis de Componente Principal/métodos , Ventrículos Cardíacos/patología , Humanos
7.
Cardiology ; 145(1): 1-12, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31715595

RESUMEN

INTRODUCTION: In dilated cardiomyopathy (DCM) left ventricular (LV) strain and twist are significantly decreased. However, the rate of attenuation has not been investigated well in patients with varying degrees of systolic dysfunction. AIM: The present study aimed to investigate the relationship between LV deformational and rotational mechanics and conventional and tissue Doppler imaging (TDI) parameters, and to search for a constellation of findings distinguishing patients with severe systolic dysfunction (SSD) in DCM. METHODS: Fifty-two patients with heart failure NYHA class III-IV and ejection fraction (EF) ≤45% were prospectively enrolled (mean age 61.8 ± 13.4 years; 36 males, 69%). Severe systolic LV dysfunction was considered as EF <30%. Echocardiography with 2D-speckle tracking analysis was performed. RESULTS: The relationships of global longitudinal strain (GLS) with EF, circumferential strain at mid-level (CSmid), and systolic medial mitral annulus velocity were strong (r = -0.53, 0.67, and -0.56, respectively, p < 0.0001 for all). A good correlation was found between CSmid and EF (r = -0.50, p < 0.0001). There were weak correlations between basal endocardial rotation (BRendo) and EF and CSmid. Multiple regression analysis found GLS (p < 0.0001) and BRendo (p = 0.04) to be predictors of the change of EF. In ROC curve analysis, the cut-off values of GLS -7.2% (AUC 0.81, p < 0.0001), CSmid -7.5% (AUC 0.76, p = 0.002), and BRendo -2.43° (AUC 0.68, p = 0.03) identified SSD. CONCLUSIONS: Parameters of LV mechanics were related to conventional and TDI systolic parameters in patients with DCM. The degree of alterations of LV longitudinal and circumferential deformation and basal rotation may identify patients with SSD and a higher risk, and may help in therapeutic decision making.


Asunto(s)
Cardiomiopatía Dilatada/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Válvula Mitral/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Anciano , Cardiomiopatía Dilatada/complicaciones , Ecocardiografía , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Rotación , Volumen Sistólico , Sístole
8.
Cardiol J ; 27(6): 789-796, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31106841

RESUMEN

BACKGROUND: Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS); however, transcatheter aortic valve implantation (TAVI) may positively affect LV mechanics. Assessed herein is the performance of the SAPIEN 3 transcatheter heart valve (THV) and the effect of TAVI on LV function recovery, as assessed by global longitudinal strain (GLS). METHODS: A subset of patients from the SOURCE 3 registry (n = 276) from 16 European centers received SAPIEN 3 balloon-expandable THV. Echocardiography was performed at baseline, postprocedure, and at 1 year, including assessment of GLS using standard two-dimensional images, and was analyzed in a core laboratory. Paired analyses between baseline and discharge, baseline and at 1 year were conducted. RESULTS: Hemodynamic parameters were improved after TAVI and sustained to 1 year. At 1 year, the rate of moderate to severe paravalvular leaks (PVL), and moderate to severe mitral and tricuspid regurgitations were 1.8%, 1.7%, and 8.0%, respectively. The discharge GLS (-15.6 ± 5.1; p = 0.004; n = 149) improved significantly from baseline (-15.1 ± 4.8) following TAVI. This improvement was sustained at 1 year compared with baseline (-17.0 ± 4.6, p < 0.001; n = 100). Conversely, LV ejection fraction (LVEF) did not significantly change following TAVI (p = 0.47). CONCLUSIONS: Following TAVI with a third-generation THV, valve performances were good at 1 year with low PVL rate. The LV mechanics improved immediately after the procedure and were maintained at 1 year. These findings demonstrate the benefit of TAVI on LV mechanics, and suggests that GLS may be superior to LVEF in assessing this benefit. Clinicaltrial.gov number: NCT02698956.


Asunto(s)
Estenosis de la Válvula Aórtica , Reemplazo de la Válvula Aórtica Transcatéter , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/cirugía , Hemodinámica , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento
9.
J R Soc Interface ; 16(156): 20190114, 2019 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-31266415

RESUMEN

In recent years, we have witnessed substantial advances in the mathematical modelling of the biomechanical processes underlying the dynamics of the cardiac soft-tissue. Gao et al. (Gao et al. 2017 J. R. Soc. Interface 14, 20170203 ( doi:10.1098/rsif.2017.0203 )) demonstrated that the parameters underlying the biomechanical model have diagnostic value for prognosticating the risk of myocardial infarction. However, the computational costs of parameter estimation are prohibitive when the goal lies in building real-time clinical decision support systems. This is due to the need to repeatedly solve the mathematical equations numerically using finite-element discretization during an iterative optimization routine. The present article presents a method for accelerating the inference of the constitutive parameters by using statistical emulation with Gaussian processes. We demonstrate how the computational costs can be reduced by about three orders of magnitude, with hardly any loss in accuracy, and we assess various alternative techniques in a comparative evaluation study based on simulated data obtained by solving the left ventricular model with the finite-element method, and real magnetic resonance images data for a human volunteer.


Asunto(s)
Simulación por Computador , Ventrículos Cardíacos , Imagen por Resonancia Magnética , Modelos Cardiovasculares , Infarto del Miocardio , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología
10.
Cardiology ; 143(1): 52-61, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31307038

RESUMEN

PURPOSE: Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). Transcatheter aortic valve replacement (TAVR) has become a widespread technique for patients with severe AS considered inoperable or high risk for open surgery. This procedure could have a positive impact in LV mechanics. The aim of the study was to evaluate the effect of TAVR on LV function recovery, as assessed by myocardial deformation parameters, both immediately and in the long term. METHODS: One-hundred nineteen consecutive patients (81.2 ± 6.9 years, 50.4% female) from 10 centres in Europe with severe AS who successfully underwent TAVR with either a self-expanding CoreValve (Medtronic, Minneapolis, MN, USA) or a mechanically expanded Lotus valve (Boston Scientific, Natick, MA, USA) were enrolled in a prospective observational study. A complete echocardiographic examination was performed prior to device implantation, before discharge and 1 year after the procedure, including the assessment of LV strain using standard 2D images. RESULTS: Between baseline and discharge, only a modest but statistically significant improvement in GLS (global longitudinal strain) could be seen (GLS% -14.6 ± 5.0 at baseline; -15.7 ± 5.1 at discharge, p = 0.0116), although restricted to patients in the CoreValve group; 1 year after the procedure, a greater improvement in GLS was observed (GLS% -17.1 ± 4.9, p < 0.001), both in the CoreValve and the Lotus groups. CONCLUSIONS: Immediate and sustained improvement in GLS was appreciated after the TAVR procedure. Whether this finding continues to be noted in a more prolonged follow-up and its clinical implications need to be assessed in further studies.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Disfunción Ventricular Izquierda/terapia , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/complicaciones , Ecocardiografía , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Estudios Prospectivos , Disfunción Ventricular Izquierda/etiología
11.
J Physiol ; 597(4): 1059-1072, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-29808473

RESUMEN

KEY POINTS: We sought to determine the isolated and combined influence of hypovolaemia and hypoxic pulmonary vasoconstriction on the decrease in left ventricular (LV) function and maximal exercise capacity observed under hypobaric hypoxia. We performed echocardiography and maximal exercise tests at sea level (344 m), and following 5-10 days at the Barcroft Laboratory (3800 m; White Mountain, California) with and without (i) plasma volume expansion to sea level values and (ii) administration of the pulmonary vasodilatator sildenafil in a double-blinded and placebo-controlled trial. The high altitude-induced reduction in LV filling and ejection was abolished by plasma volume expansion but to a lesser extent by sildenafil administration; however, neither intervention had a positive effect on maximal exercise capacity. Both hypovolaemia and hypoxic pulmonary vasoconstriction play a role in the reduction of LV filling at 3800 m, but the increase in LV filling does not influence exercise capacity at this moderate altitude. ABSTRACT: We aimed to determine the isolated and combined contribution of hypovolaemia and hypoxic pulmonary vasoconstriction in limiting left ventricular (LV) function and exercise capacity under chronic hypoxaemia at high altitude. In a double-blinded, randomised and placebo-controlled design, 12 healthy participants underwent echocardiography at rest and during submaximal exercise before completing a maximal test to exhaustion at sea level (SL; 344 m) and after 5-10 days at 3800 m. Plasma volume was normalised to SL values, and hypoxic pulmonary vasoconstriction was reversed by administration of sildenafil (50 mg) to create four unique experimental conditions that were compared with SL values: high altitude (HA), Plasma Volume Expansion (HA-PVX), Sildenafil (HA-SIL) and Plasma Volume Expansion with Sildenafil (HA-PVX-SIL). High altitude exposure reduced plasma volume by 11% (P < 0.01) and increased pulmonary artery systolic pressure (19.6 ± 4.3 vs. 26.0 ± 5.4, P < 0.001); these differences were abolished by PVX and SIL respectively. LV end-diastolic volume (EDV) and stroke volume (SV) were decreased upon ascent to high altitude, but were comparable to sea level in the HA-PVX trial. LV EDV and SV were also elevated in the HA-SIL and HA-PVX-SIL trials compared to HA, but to a lesser extent. Neither PVX nor SIL had a significant effect on the LV EDV and SV response to exercise, or the maximal oxygen consumption or peak power output. In summary, at 3800 m both hypovolaemia and hypoxic pulmonary vasoconstriction contribute to the decrease in LV filling, but restoring LV filling does not confer an improvement in maximal exercise performance.


Asunto(s)
Altitud , Tolerancia al Ejercicio , Hipovolemia/fisiopatología , Hipoxia/fisiopatología , Pulmón/irrigación sanguínea , Vasoconstricción , Función Ventricular , Aclimatación , Adulto , Diástole , Humanos , Pulmón/fisiología , Pulmón/fisiopatología , Masculino , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/fisiología , Arteria Pulmonar/fisiopatología , Citrato de Sildenafil/farmacología , Vasodilatadores/farmacología
12.
Ultrasound Obstet Gynecol ; 54(3): 350-358, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30426576

RESUMEN

OBJECTIVE: To evaluate left ventricular (LV) mechanics in the second trimester of healthy pregnancy and to determine the influence of underpinning hemodynamics (heart rate (HR), preload and afterload) on LV mechanics during gestation. METHODS: This was a cross-sectional study of 18 non-pregnant, 14 nulliparous pregnant (22-26 weeks' gestation) and 13 primiparous postpartum (12-16 weeks after delivery) women. All pregnant and postpartum women had uncomplicated, singleton gestations. Cardiac structure and function were assessed using echocardiography. LV mechanics, specifically longitudinal strain, circumferential strain and twist/untwist, were measured using speckle-tracking echocardiography. Differences between groups were identified using ANCOVA, with age, HR, end-diastolic volume (EDV) and systolic blood pressure (SBP) as covariates. Relationships between LV mechanics and hemodynamics were examined using Pearson's correlation. RESULTS: There were no significant differences in LV structure and traditional measurements of systolic and diastolic function between the three groups. Pregnant women, compared with non-pregnant ones, had significantly higher resting longitudinal strain (-22 ± 2% vs -17 ± 3%; P = 0.002) and basal circumferential strain (-23 ± 4% vs -16 ± 2%; P = 0.001). Apical circumferential strain and LV twist and untwist mechanics were similar between the three groups. No statistically significant relationships were observed between LV mechanics and HR, EDV or SBP within the groups. CONCLUSIONS: Compared to the non-pregnant state, pregnant women in the second trimester of a healthy pregnancy have significantly greater resting systolic function, as assessed by LV longitudinal and circumferential strain. Contrary to previous work, these data show that healthy pregnant women should not exhibit reductions in resting systolic function between 22 and 26 weeks' gestation. The enhanced myocardial contractile function during gestation does not appear to be related to hemodynamic load and could be the result of other physiological adaptations to pregnancy. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Adaptación Fisiológica/fisiología , Segundo Trimestre del Embarazo/fisiología , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Adulto , Estudios Transversales , Ecocardiografía , Femenino , Hemodinámica , Humanos , Embarazo , Reino Unido/epidemiología
13.
Echocardiography ; 35(10): 1564-1570, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29962073

RESUMEN

BACKGROUND: Cardiac shockwave therapy (CSWT) is a new potential option for the treatment of patients with chronic coronary disease and refractory angina (RA). We aimed to study the effects of CSWT on left ventricular myocardial perfusion and mechanics in patients with RA. METHOD: We prospectively studied 19 patients who underwent CSWT. Left ventricular mechanics were evaluated by speckle tracking echocardiography (STE), and myocardial perfusion by single-photon emission computed tomography, using stress/rest-Technetium-99 m Sestamibi, for determination of summed stress score (SSS). Canadian Cardiac Society (CCS), New York Heart Association (NYHA), and quality of life by Seattle Angina Questionnaire (SAQ) were assessed at baseline and 6 months after therapy. RESULTS: CSWT therapy was applied without major side effects. At baseline, 18 patients (94.7%) had CCS class III or IV, and after CSWT there was reduction to 3 (15.8%), P = .0001, associated with improvement in SAQ (38.5%; P < .001). Thirteen (68.4%) had class NYHA III or IV before treatment, with significant reduction to 7 (36.8%); P = .014. No change was observed in the global SSS from baseline to 6-month follow-up (15.33 ± 8.60 vs 16.60 ± 8.06; P = .157). However, there was a significant reduction in the average SSS of the treated ischemic segments (2.1 ± 0.87 pre vs 1.6 ± 1.19 post CSWT; P = .024). Global longitudinal strain by STE remained unaltered (-13.03 ± 8.96 pre vs -15.88 ± 3.43 6-month post CSWT; P = .256). CONCLUSION: CSWT is a safe procedure for the treatment of patients with RA that results in better quality of life, improvement in myocardial perfusion of the treated segments with preservation of left ventricular mechanics.


Asunto(s)
Angina de Pecho/terapia , Ecocardiografía/métodos , Tratamiento con Ondas de Choque Extracorpóreas/métodos , Corazón/fisiología , Disfunción Ventricular Izquierda/terapia , Angina de Pecho/complicaciones , Angina de Pecho/fisiopatología , Femenino , Corazón/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único , Resultado del Tratamiento , Disfunción Ventricular Izquierda/complicaciones , Disfunción Ventricular Izquierda/fisiopatología
14.
Eur J Appl Physiol ; 118(7): 1291-1299, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29869711

RESUMEN

BACKGROUND: The cardiac consequences of undertaking endurance exercise are the topic of recent debate. The purpose of this review is to provide an update on a growing body of literature, focusing on left ventricular (LV) function following prolonged endurance exercise over 2 h in duration which have employed novel techniques, including myocardial speckle tracking, to provide a more comprehensive global and regional assessment of LV mechanics. METHODS: Prospective studies were filtered independently following a pre-set criteria, resulting in the inclusion of 27 studies in the analyses. A random-effects meta-analysis was used to determine the weighted mean difference and 95% confidence intervals (CI) of LV functional and mechanical data from pre-to-post-exercise. Narrative commentary was also provided where volume of available evidence precluded meta-analysis. RESULTS: A significant overall reduction in LV longitudinal strain (Ɛ) n = 22 (- 18 ± 1 to - 17 ± 1%; effect size (d) - 9: - 1 to - 0.5%), strain rate n = 10 (SR; d - 0.9: - 0.1.3 to - 0.5 l/s) and twist n = 5 (11.9 ± 2.2 to 8.7 ± 2.2°, d - 1: - 1.6 to - 0.3°) was observed following strenuous endurance exercise (range 120-1740 min) (P < 0.01). A smaller number of studies (n = 4) also reported a non-significant reduction in global circumferential and radial Ɛ (P > 0.05). CONCLUSION: The meta-analysis and narrative commentary demonstrated that a reduction in LV function and mechanics is evident following prolonged endurance exercise. The mechanism(s) responsible for these changes are complex and likely multi-factorial in nature and may be linked to right and left ventricular interaction.


Asunto(s)
Acondicionamiento Físico Humano/métodos , Función Ventricular Izquierda , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Contracción Miocárdica
15.
Cardiol J ; 25(4): 487-494, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29924376

RESUMEN

BACKGROUND: Left ventricular (LV) mechanics are impaired in patients with severe aortic stenosis (AS). Transcatheter aortic valve replacement (TAVR) has become a widespread technique for patients with severe AS considered inoperable or high risk for traditional open-surgery. This procedure could have a positive impact in LV mechanics. The aim of this study was to evaluate the immediate effect of TAVR on LV function recovery, as assessed by myocardial deformation parameters. METHODS: One-hundred twelve consecutive patients (81.4 ± 6.4 years, 50% female) from 10 centres in Europe with severe AS who successfully underwent TAVR with either a self-expanding CoreValve (Medtronic, Minneapolis, MN) or a mechanically expanded Lotus valve (Boston Scientific, Natick, MA) were enrolled in a prospective multi-center study. A complete echocardiographic examination was performed at baseline and immediately before discharge, including the assessment of LV strain using standard two-dimensional images. RESULTS: Echocardiographic examination with global longitudinal strain (GLS) quantification could be obtained in 92 patients, because of echocardiographic and logistic reasons. Between examinations, a modest statistically significant improvement in GLS could be seen (GLS% -15.00 ± 4.80 at baseline;-16.15 ± 4.97 at discharge, p = 0.028). In a stratified analysis, only women showed a significant improvement in GLS and a trend towards greater improvement in GLS according to severity of systolic dysfunction as measured by LV ejection fraction could be noted. CONCLUSIONS: Immediate improvement in GLS was appreciated after TAVR procedure. Whether this finding continues to be noted in a more prolonged follow-up and its clinical implications need to be assessed in further studies.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Ventrículos Cardíacos/fisiopatología , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Función Ventricular Izquierda/fisiología , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/fisiopatología , Ecocardiografía , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Periodo Posoperatorio , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento
16.
Am J Physiol Heart Circ Physiol ; 315(3): H687-H698, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29856652

RESUMEN

Left ventricular (LV) twist mechanics differ between men and women during acute physiological stress, which may be partly mediated by sex differences in autonomic control. While men appear to have greater adrenergic control of LV twist, the potential contribution of vagal modulation to sex differences in LV twist remains unknown. Therefore, the present study examined the role of vagal control on sex differences in LV twist during graded lower body negative pressure (LBNP) and supine cycling. On two separate visits, LV mechanics were assessed using two-dimensional speckle-tracking echocardiography in 18 men (22 ± 2 yr) and 17 women (21 ± 4 yr) during -40- and -60-mmHg LBNP and 25% and 50% of peak supine cycling workload with and without glycopyrrolate (vagal blockade). LV twist was not different at baseline but was greater in women during -60 mmHg in both control (women: 16.0 ± 3.4° and men: 12.9 ± 2.3°, P = 0.004) and glycopyrrolate trials (women: 17.7 ± 5.9° and men: 13.9 ± 3.3°, P < 0.001) due to greater apical rotation during control (women: 11.9 ± 3.6° and men: 7.8 ± 1.5°, P < 0.001) and glycopyrrolate (women: 11.6 ± 4.9° and men: 7.1 ± 3.6°, P = 0.009). These sex differences in LV twist consistently coincided with a greater LV sphericity index (i.e., ellipsoid geometry) in women compared with men. In contrast, LV twist did not differ between the sexes during exercise with or without glycopyrrolate. In conclusion, women have augmented LV twist compared with men during large reductions to preload, even during vagal blockade. As such, differences in vagal control do not appear to contribute to sex differences in the LV twist responses to physiological stress, but they may be related to differences in ventricular geometry. NEW & NOTEWORTHY This is the first study to specifically examine the role of vagal autonomic control on sex-related differences in left ventricular (LV) mechanics. Contrary to our hypothesis, vagal control does not appear to primarily determine sex differences in LV mechanical or hemodynamic responses to acute physiological stress. Instead, differences in LV geometry may be a more important contributor to sex differences in LV mechanics.


Asunto(s)
Hemodinámica , Nervio Vago/fisiología , Función Ventricular Izquierda , Adulto , Fenómenos Biomecánicos , Femenino , Glicopirrolato/farmacología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/inervación , Humanos , Presión Negativa de la Región Corporal Inferior , Masculino , Antagonistas Muscarínicos/farmacología , Factores Sexuales , Nervio Vago/efectos de los fármacos
17.
Heart Rhythm ; 15(10): 1533-1539, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29604420

RESUMEN

BACKGROUND: Myocardial fibrosis (macroscopic scar or diffuse reactive fibrosis) is one of the determinants of impaired left ventricular (LV) global longitudinal strain (GLS) in heart failure (HF) patients. OBJECTIVE: The purpose of this study was to evaluate the prognostic value of LV GLS in HF patients treated with cardiac resynchronization therapy (CRT). METHODS: The study included 829 HF patients (mean age 64.6 ± 10.4 years; 72% men) treated with CRT. Before CRT implantation, LV GLS was assessed using 2-dimensional speckle tracking echocardiography. The primary endpoint was the combination of all-cause mortality, heart transplantation, and LV assist device implantation. The secondary endpoint was the occurrence of ventricular arrhythmias or appropriate implantable defibrillator device therapies. RESULTS: During follow-up, 332 patients reached the primary endpoint, and 233 presented with the secondary endpoint. Patients were divided according to LV GLS quartiles. Patients with the most impaired LV GLS quartile had a 2-fold higher risk of reaching the combined endpoint compared with patients in the best LV GLS quartile (hazard ratio [HR] 2.088; 95% confidence interval [CI] 1.555-2.804; P <.001). LV GLS was significantly associated with the combined endpoint (HR 1.075; 95% CI 1.020-1.133; P = .007) after adjusting for clinical, electrocardiographic, and echocardiographic characteristics. Although patients in the most impaired LV GLS quartile showed higher event rates for the secondary endpoint compared with the other groups, LV GLS was not independently associated with the secondary endpoint (HR 1.047; 95% CI 0.989-1.107; P = .115). CONCLUSION: In this large cohort of CRT patients, baseline LV GLS was independently associated with the combined endpoint.


Asunto(s)
Terapia de Resincronización Cardíaca/métodos , Insuficiencia Cardíaca/terapia , Ventrículos Cardíacos/fisiopatología , Estrés Fisiológico/fisiología , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Anciano , Ecocardiografía , Electrocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Imagen por Resonancia Cinemagnética , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo
18.
Climacteric ; 20(5): 476-483, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28786704

RESUMEN

OBJECTIVES: Cardiovascular function generally decreases with age, but whether this decrease differs between men and women is unclear. Our aims were twofold: (1) to investigate age-related sex differences in left ventricular (LV) structure, function and mechanics, and (2) to compare these measures between pre- and postmenopausal women in the middle-aged group. METHODS: Resting echocardiography was performed in a cross-sectional sample of 82 healthy adults (14 young men, 19 middle-aged men, 15 young women, 34 middle-aged women: 15 premenopausal and 19 postmenopausal). Two-way ANOVAs were used to examine sex × age interactions, and t-tests to compare pre- and postmenopausal women (α < 0.1). RESULTS: Normalized LV mass, stroke volume and end-diastolic volume were significantly lower in middle-aged than young men, but this difference was smaller between middle-aged and young women. Peak systolic apical mechanics were significantly greater in middle-aged men than in middle-aged women, but not between young men and women. Postmenopausal women had significantly lower LV relaxation and mechanics (torsion, twisting velocity and apical circumferential strain rates) compared with middle-aged premenopausal women. CONCLUSION: Our cross-sectional findings suggest that the hearts of men and women may age differently, with men displaying greater differences in LV volumes accompanied by differences in apical mechanics.


Asunto(s)
Envejecimiento/fisiología , Ventrículos Cardíacos/anatomía & histología , Posmenopausia/fisiología , Función Ventricular Izquierda/fisiología , Adulto , Factores de Edad , Fenómenos Biomecánicos , Estudios Transversales , Diástole , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Sexuales , Volumen Sistólico
19.
J Appl Physiol (1985) ; 123(2): 394-401, 2017 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-28522755

RESUMEN

Individuals with type 1 diabetes (T1D) characteristically have high glycemic levels that over time can result in reactive fibrosis and abnormalities in myocardial function. T1 mapping with magnetic resonance imaging (MRI) can estimate the extent of reactive fibrosis by measurement of the extracellular volume fraction (ECV). The extent of alterations in the ECV and associated changes in left ventricular (LV) function and morphology in individuals with T1D is unknown. Fourteen individuals with long-term T1D and 14 sex-, age-, and body mass index-matched controls without diabetes underwent MRI measurement of myocardial T1 and ECV values as well as LV function and morphology. Ventricular mass, volumes, and global function (LVEF and circumferential/longitudinal/radial strain) were similar in those with T1D and controls. However, those with T1D had larger myocardial ECV (22.1 ± 1.8 vs. 20.1 ± 2.1, P = 0.008) and increased native (noncontrast) myocardial T1 values (1,211 ± 44 vs. 1,172 ± 43 ms, P < 0.001) as compared with controls. Both the ECV and native T1 values significantly correlated with several components of torsion and circumferential-longitudinal shear strain (Ecl, the shear strain component associated with twist). Individuals with T1D had increased systolic torsion (P = 0.035), systolic torsion rate (P = 0.032), peak Ecl (P = 0.001), and rates of change of systolic (P = 0.007) and diastolic (P = 0.007) Ecl Individuals with T1D, with normal structure, LVEF, and strain, have increased extracellular volume and increased native T1 values with associated augmented torsion and Ecl These measures may be useful in detecting the early stages of diabetic cardiomyopathy and warrant larger prospective studies.NEW & NOTEWORTHY Individuals with type 1 diabetes, with normal left ventricular structure and function (ejection fraction and strain), have signs of interstitial fibrosis, measured with MRI as increased extracellular volume fraction and increased native myocardial T1, which significantly correlated with a number of measures of augmented left ventricular twist function. These measures may be useful in detecting the early stages of diabetic cardiomyopathy.


Asunto(s)
Diabetes Mellitus Tipo 1/fisiopatología , Ventrículos Cardíacos/fisiopatología , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Cardiomiopatías/fisiopatología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miocardio
20.
J Physiol ; 595(12): 3973-3985, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28188951

RESUMEN

KEY POINTS: Sex differences in left ventricular (LV) mechanics occur during acute physiological challenges; however, it is unknown whether sex differences in LV mechanics are fundamentally regulated by differences in adrenergic control. Using two-dimensional echocardiography and speckle tracking analysis, this study compared LV mechanics in males and females matched for LV length during post-exercise ischaemia (PEI) and ß1 -adrenergic receptor blockade. Our data demonstrate that while basal rotation was increased in males, LV twist was not significantly different between the sexes during PEI. In contrast, during ß1 -adrenergic receptor blockade, LV apical rotation, twist and untwisting velocity were reduced in males compared to females. Significant relationships were observed between LV twist and LV internal diameter and sphericity index in females, but not males. These findings suggest that LV twist mechanics may be more sensitive to alterations in adrenergic stimulation in males, but more highly influenced by ventricular structure and geometry in females. ABSTRACT: Sex differences in left ventricular (LV) mechanics exist at rest and during acute physiological stress. Differences in cardiac autonomic and adrenergic control may contribute to sex differences in LV mechanics and LV haemodynamics. Accordingly, this study aimed to investigate sex differences in LV mechanics with altered adrenergic stimulation achieved through post-handgrip-exercise ischaemia (PEI) and ß1 -adrenergic receptor (AR) blockade. Twenty males (23 ± 5 years) and 20 females (22 ± 3 years) were specifically matched for LV length (males: 8.5 ± 0.5 cm, females: 8.2 ± 0.6 cm, P = 0.163), and two-dimensional speckle-tracking echocardiography was used to assess LV structure and function at baseline, during PEI and following administration of 5 mg bisoprolol (ß1 -AR antagonist). During PEI, LV end-diastolic volume and stroke volume were increased in both groups (P < 0.001), as was end-systolic wall stress (P < 0.001). LV twist and apical rotation were not altered from baseline or different between the sexes; however, basal rotation increased in males (P = 0.035). During ß1 -AR blockade, LV volumes were unchanged but blood pressure and heart rate were reduced in both groups (P < 0.001). LV apical rotation (P = 0.036) and twist (P = 0.029) were reduced in males with ß1 -AR blockade but not females, resulting in lower apical rotation (males: 6.8 ± 2.1 deg, females: 8.8 ± 2.3 deg, P = 0.007) and twist (males: 8.6 ± 1.9 deg, females: 10.7 ± 2.8 deg, P = 0.008), and slower untwisting velocity (males: 68.2 ± 22.1 deg s-1 , females: 82.0 ± 18.7 deg s-1 , P = 0.046) compared to females. LV twist mechanics are reduced in males compared to females during reductions to adrenergic stimulation, providing preliminary evidence that LV twist mechanics may be more sensitive to adrenergic control in males than in females.


Asunto(s)
Adrenérgicos/farmacología , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/fisiopatología , Función Ventricular Izquierda/efectos de los fármacos , Función Ventricular Izquierda/fisiología , Adulto , Presión Sanguínea/efectos de los fármacos , Ecocardiografía/métodos , Ejercicio Físico/fisiología , Femenino , Fuerza de la Mano/fisiología , Corazón/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Masculino , Contracción Miocárdica/efectos de los fármacos , Descanso/fisiología , Rotación , Caracteres Sexuales , Volumen Sistólico/efectos de los fármacos , Adulto Joven
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