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1.
Nat Commun ; 15(1): 4166, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755146

RESUMO

Failure of proper ventricular trabeculation is often associated with congenital heart disease. Support from endocardial cells, including the secretion of extracellular matrix and growth factors is critical for trabeculation. However, it is poorly understood how the secretion of extracellular matrix and growth factors is initiated and regulated by endocardial cells. We find that genetic knockout of histone deacetylase 3 in the endocardium in mice results in early embryo lethality and ventricular hypotrabeculation. Single cell RNA sequencing identifies significant downregulation of extracellular matrix components in histone deacetylase 3 knockout endocardial cells. Secretome from cultured histone deacetylase 3 knockout mouse cardiac endothelial cells lacks transforming growth factor ß3 and shows significantly reduced capacity in stimulating cultured cardiomyocyte proliferation, which is remarkably rescued by transforming growth factor ß3 supplementation. Mechanistically, we identify that histone deacetylase 3 knockout induces transforming growth factor ß3 expression through repressing microRNA-129-5p. Our findings provide insights into the pathogenesis of congenital heart disease and conceptual strategies to promote myocardial regeneration.


Assuntos
Endocárdio , Histona Desacetilases , Camundongos Knockout , MicroRNAs , Miócitos Cardíacos , Animais , Endocárdio/metabolismo , Camundongos , MicroRNAs/metabolismo , MicroRNAs/genética , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Miócitos Cardíacos/metabolismo , Fator de Crescimento Transformador beta3/metabolismo , Fator de Crescimento Transformador beta3/genética , Proliferação de Células , Miocárdio/metabolismo , Células Endoteliais/metabolismo , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/patologia , Matriz Extracelular/metabolismo , Feminino
2.
JACC Clin Electrophysiol ; 10(6): 1150-1160, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38703167

RESUMO

BACKGROUND: Assessment of origin of ventricular tachycardias (VTs) arising from epicardial vs endocardial sites are largely challenged by the available criteria and etiology of cardiomyopathy. Current electrocardiographic (ECG) criteria based on 12-lead ECG have varying sensitivity and specificity based on site of origin and etiology of cardiomyopathy. OBJECTIVES: This study sought to test the hypothesis that epicardial VT has a slower initial rate of depolarization than endocardial VT. METHODS: We developed a method that takes advantage of the fact that electrical conduction is faster through the cardiac conduction system than the myocardium, and that the conduction system is primarily an endocardial structure. The technique calculated the rate of change in the initial VT depolarization from a signal-averaged 12-lead ECG. We hypothesized that the rate of change of depolarization in endocardial VT would be faster than epicardial. We assessed by applying this technique among 26 patients with VT in nonischemic cardiomyopathy patients. RESULTS: When comparing patients with VTs ablated using epicardial and endocardial approaches, the rate of change of depolarization was found to be significantly slower in epicardial (6.3 ± 3.1 mV/s vs 11.4 ± 3.7 mV/s; P < 0.05). Statistical significance was found when averaging all 12 ECG leads and the limb leads, but not the precordial leads. Follow up analysis by calculation of a receiver-operating characteristic curve demonstrated that this analysis provides a strong prediction if a VT is epicardial in origin (AUC range 0.72-0.88). Slower rate of change of depolarization had high sensitivity and specificity for prediction of epicardial VT. CONCLUSIONS: This study demonstrates that depolarization rate analysis is a potential technique to predict if a VT is epicardial in nature.


Assuntos
Eletrocardiografia , Endocárdio , Pericárdio , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Endocárdio/fisiopatologia , Pericárdio/fisiopatologia , Idoso , Sistema de Condução Cardíaco/fisiopatologia , Cardiomiopatias/fisiopatologia , Adulto , Ablação por Cateter , Sensibilidade e Especificidade
3.
Comput Biol Med ; 174: 108490, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38642490

RESUMO

BACKGROUND: Pulsed Field Ablation (PFA) has recently been proposed as a non-thermal energy to treat atrial fibrillation by selective ablation of ganglionated plexi (GP) embedded in epicardial fat. While some of PFA-technologies use an endocardial approach, others use epicardial access with promising pre-clinical results. However, as each technology uses a different and sometimes proprietary pulse application protocol, the comparation between endocardial vs. epicardial approach is almost impossible in experimental terms. For this reason, our study, based on a computational model, allows a direct comparison of electric field distribution and thermal-side effects of both approaches under equal conditions in terms of electrode design, pulse protocol and anatomical characteristics of the tissues involved. METHODS: 2D computational models with axial symmetry were built for endocardial and epicardial approaches. Atrial (1.5-2.5 mm) and fat (1-5 mm) thicknesses were varied to simulate a representative sample of what happens during PFA ablation for different applied voltage values (1000, 1500 and 2000 V) and number of pulses (30 and 50). RESULTS: The epicardial approach was superior for capturing greater volumes of fat when the applied voltage was increased: 231 mm3/kV with the epicardial approach vs. 182 mm3/kV with the endocardial approach. In relation to collateral damage to the myocardium, the epicardial approach considerably spares the myocardium, unlike what happens with the endocardial approach. Although the epicardial approach caused much more thermal damage in the fat, there is not a significant difference between the approaches in terms of size of thermal damage in the myocardium. CONCLUSIONS: Our results suggest that epicardial PFA ablation of GPs is more effective than an endocardial approach. The proximity and directionality of the electric field deposited using an epicardial approach are key to ensuring that higher electric field strengths and increased temperatures are obtained within the epicardial fat, thus contributing to selective ablation of the GPs with minimal myocardial damage.


Assuntos
Fibrilação Atrial , Simulação por Computador , Endocárdio , Modelos Cardiovasculares , Pericárdio , Endocárdio/fisiopatologia , Humanos , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos
4.
Circ Res ; 134(11): 1465-1482, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38655691

RESUMO

BACKGROUND: Preclinical studies have shown the therapeutic potential of VEGF-B (vascular endothelial growth factor B) in revascularization of the ischemic myocardium, but the associated cardiac hypertrophy and adverse side effects remain a concern. To understand the importance of endothelial proliferation and migration for the beneficial versus adverse effects of VEGF-B in the heart, we explored the cardiac effects of autocrine versus paracrine VEGF-B expression in transgenic and gene-transduced mice. METHODS: We used single-cell RNA sequencing to compare cardiac endothelial gene expression in VEGF-B transgenic mouse models. Lineage tracing was used to identify the origin of a VEGF-B-induced novel endothelial cell population and adeno-associated virus-mediated gene delivery to compare the effects of VEGF-B isoforms. Cardiac function was investigated using echocardiography, magnetic resonance imaging, and micro-computed tomography. RESULTS: Unlike in physiological cardiac hypertrophy driven by a cardiomyocyte-specific VEGF-B transgene (myosin heavy chain alpha-VEGF-B), autocrine VEGF-B expression in cardiac endothelium (aP2 [adipocyte protein 2]-VEGF-B) was associated with septal defects and failure to increase perfused subendocardial capillaries postnatally. Paracrine VEGF-B led to robust proliferation and myocardial migration of a novel cardiac endothelial cell lineage (VEGF-B-induced endothelial cells) of endocardial origin, whereas autocrine VEGF-B increased proliferation of VEGF-B-induced endothelial cells but failed to promote their migration and efficient contribution to myocardial capillaries. The surviving aP2-VEGF-B offspring showed an altered ratio of secreted VEGF-B isoforms and developed massive pathological cardiac hypertrophy with a distinct cardiac vessel pattern. In the normal heart, we found a small VEGF-B-induced endothelial cell population that was only minimally expanded during myocardial infarction but not during physiological cardiac hypertrophy associated with mouse pregnancy. CONCLUSIONS: Paracrine and autocrine secretions of VEGF-B induce expansion of a specific endocardium-derived endothelial cell population with distinct angiogenic markers. However, autocrine VEGF-B signaling fails to promote VEGF-B-induced endothelial cell migration and contribution to myocardial capillaries, predisposing to septal defects and inducing a mismatch between angiogenesis and myocardial growth, which results in pathological cardiac hypertrophy.


Assuntos
Cardiomegalia , Linhagem da Célula , Endocárdio , Células Endoteliais , Camundongos Transgênicos , Fator B de Crescimento do Endotélio Vascular , Animais , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/genética , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Fator B de Crescimento do Endotélio Vascular/metabolismo , Fator B de Crescimento do Endotélio Vascular/genética , Camundongos , Endocárdio/metabolismo , Endocárdio/patologia , Comunicação Parácrina , Proliferação de Células , Comunicação Autócrina , Camundongos Endogâmicos C57BL , Feminino , Masculino , Movimento Celular
5.
PLoS One ; 19(4): e0300978, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38625849

RESUMO

Cardiac fibrosis stands as one of the most critical conditions leading to lethal cardiac arrhythmias. Identifying the precise location of cardiac fibrosis is crucial for planning clinical interventions in patients with various forms of ventricular and atrial arrhythmias. As fibrosis impedes and alters the path of electrical waves, detecting fibrosis in the heart can be achieved through analyzing electrical signals recorded from its surface. In current clinical practices, it has become feasible to record electrical activity from both the endocardial and epicardial surfaces of the heart. This paper presents a computational method for reconstructing 3D fibrosis using unipolar electrograms obtained from both surfaces of the ventricles. The proposed method calculates the percentage of fibrosis in various ventricular segments by analyzing the local activation times and peak-to-peak amplitudes of the electrograms. Initially, the method was tested using simulated data representing idealized fibrosis in a heart segment; subsequently, it was validated in the left ventricle with fibrosis obtained from a patient with nonischemic cardiomyopathy. The method successfully determined the location and extent of fibrosis in 204 segments of the left ventricle model with an average error of 0.0±4.3% (N = 204). Moreover, the method effectively detected fibrotic scars in the mid-myocardial region, a region known to present challenges in accurate detection using electrogram amplitude as the primary criterion.


Assuntos
Cardiomiopatias , Ventrículos do Coração , Humanos , Cicatriz , Coração , Endocárdio , Arritmias Cardíacas , Eletrocardiografia
6.
Artigo em Inglês | MEDLINE | ID: mdl-38522867

RESUMO

Endocardial fibroelastosis (EFE) is a thickening of the endocardial layer by accumulation of collagen and elastic fibers. Endothelial to mesenchymal transformation is proposed to be the underlying mechanism of formation. Although EFE can occur in both right and left ventricles, this article will focus on management of left ventricular EFE. Through its fibrous, nonelastic manifestation EFE restricts the myocardium leading to diastolic and systolic ventricular dysfunction and prevents ventricular growth in neonates and infants. The presence of EFE may be a marker for underlying myocardial fibrosis as well. The extent of EFE within the left ventricular cavity can be variable ranging from patchy to confluent distribution. Similarly the depth of penetration and degree of infiltration into myocardium can be variable. The management of EFE is controversial, although resection of EFE has been reported as part of the staged ventricular recruitment therapy. Following resection, EFE recurs and infiltrates the myocardium after primary resection. Herein we review the current experience with EFE resection.


Assuntos
Fibroelastose Endocárdica , Lactente , Recém-Nascido , Humanos , Fibroelastose Endocárdica/cirurgia , Endocárdio/cirurgia , Ventrículos do Coração , Colágeno
7.
Interv Cardiol Clin ; 13(2): 217-225, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38432764

RESUMO

Left ventricular outflow tract (LVOT) obstruction is a life-threatening complication of transcatheter mitral valve replacement. In-depth analysis of pre-procedural computed tomography enables accurate prediction of this risk. Several techniques for LVOT modification, including Laceration of the Anterior Mitral leaflet to Prevent Outflow ObtructioN, preemptive alcohol septal ablation, preemptive radiofrequency ablation, and Septal Scoring Along the Midline Endocardium, have been described as effective strategies to mitigate this risk. This review aims to explore the indications, procedural steps, and outcomes associated with these LVOT modification techniques.


Assuntos
Endocárdio , Valva Mitral , Humanos , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Tomografia Computadorizada por Raios X
8.
J Cardiovasc Electrophysiol ; 35(5): 965-974, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38477371

RESUMO

INTRODUCTION: Repolarization dispersion in the right ventricular outflow tract (RVOT) contributes to the type-1 electrocardiographic (ECG) phenotype of Brugada syndrome (BrS), while data on the significance and feasibility of mapping repolarization dispersion in BrS patients are scarce. Moreover, the role of endocardial repolarization dispersion in BrS is poorly investigated. We aimed to assess endocardial repolarization patterns through an automated calculation of activation recovery interval (ARI) estimated on unipolar electrograms (UEGs) in spontaneous type-1 BrS patients and controls; we also investigated the relation between ARI and right ventricle activation time (RVAT), and T-wave peak-to-end interval (Tpe) in BrS patients. METHODS: Patients underwent endocardial high-density electroanatomical mapping (HDEAM); BrS showing an overt type-1 ECG were defined as OType1, while those without (latent type-1 ECG and LType1) received ajmaline infusion. BrS patients only underwent programmed ventricular stimulation (PVS). Data were elaborated to obtain ARI corrected with the Bazett formula (ARIc), while RVAT was derived from activation maps. RESULTS: 39 BrS subjects (24 OType1 and 15 LTtype1) and 4 controls were enrolled. OType1 and post-ajmaline LType1 showed longer mean ARIc than controls (306 ± 27.3 ms and 333.3 ± 16.3 ms vs. 281.7 ± 10.3 ms, p = .05 and p < .001, respectively). Ajmaline induced a significant prolongation of ARIc compared to pre-ajmaline LTtype1 (333.3 ± 16.3 vs. 303.4 ± 20.7 ms, p < .001) and OType1 (306 ± 27.3 ms, p < .001). In patients with type-1 ECG (OTtype1 and post-ajmaline LType1) ARIc correlated with RVAT (r = .34, p = .04) and Tpec (r = .60, p < .001), especially in OType1 subjects (r = .55, p = .008 and r = .65 p < .001, respectively). CONCLUSION: ARIc mapping demonstrates increased endocardial repolarization dispersion in RVOT in BrS. Endocardial ARIc positively correlates with RVAT and Tpec, especially in OType1.


Assuntos
Potenciais de Ação , Algoritmos , Síndrome de Brugada , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Endocárdio , Frequência Cardíaca , Valor Preditivo dos Testes , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Síndrome de Brugada/fisiopatologia , Síndrome de Brugada/diagnóstico , Endocárdio/fisiopatologia , Adulto , Fatores de Tempo , Estudos de Casos e Controles , Ajmalina/administração & dosagem , Automação , Função Ventricular Direita , Estimulação Cardíaca Artificial , Idoso , Processamento de Sinais Assistido por Computador
10.
Heart Rhythm ; 21(6): 790-798, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38336196

RESUMO

BACKGROUND: Bipolar radiofrequency ablation (B-RFA) is a method used to treat the arrhythmia substrate resistant to unipolar ablation. Few studies have addressed endo-epicardial B-RFA. OBJECTIVE: The aim of the study was to evaluate chronic lesions resulting from endo-epicardial B-RFA and to determine optimal settings for such procedures in an animal model. METHODS: In 7 pigs, up to 5 radiofrequency applications per animal were performed with 2 electrodes placed on both sides of the left ventricular free wall. Current was delivered for 60 seconds by a generator dedicated for B-RFA with power settings of 25, 30, 35, 40, and 50 W. RESULTS: At 12 weeks after ablation, 31 lesions were assessed. Their maximal cross-sectional area ranged from 7.2 to 68 mm2 and correlated with total power delivered (r = 0.53), with temperature increment at the endocardial catheter (r = 0.65), and inversely with temperature decrement at the epicardial catheter (r = 0.54). For power values between 30 and 40 W, the lesion area did not differ significantly (P = .92). Lesion depth ranged from 1.9 to 11 mm and correlated with impedance decrement (r = 0.5). Lesions were transmural in 8 cases. Lesion depth/wall thickness ratio was on average 0.6 ± 0.3, with the smallest value for 25 W (0.5 ± 0.3) and the largest for 50 W (0.8 ± 0.3). Steam pops occurred at a power range of 30-50 W, with an incidence of 1 in 5 applications, with 1 case of fatal tamponade at 40 W. Impedance decrement, endocardial catheter temperature increment, and endocardial electrogram amplitude decrement were greater during applications with steam pops. CONCLUSION: Chronic lesions resulting from endo-epicardial B-RFA appear smaller and less often transmural compared with acute lesions described in the literature. The incidence of steam pops during endo-epicardial B-RFA is relatively high even at low powers.


Assuntos
Ablação por Cateter , Modelos Animais de Doenças , Endocárdio , Estudos de Viabilidade , Pericárdio , Animais , Suínos , Pericárdio/cirurgia , Endocárdio/cirurgia , Ablação por Cateter/métodos , Ventrículos do Coração/fisiopatologia , Desenho de Equipamento
12.
Cell Rep ; 43(2): 113736, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38308842

RESUMO

Previous studies have suggested that the endocardium contributes to hematopoiesis in murine embryos, although definitive evidence to demonstrate the hematopoietic potential of the endocardium is still missing. Here, we use a zebrafish embryonic model to test the emergence of hematopoietic progenitors from the endocardium. By using a combination of expression analysis, time-lapse imaging, and lineage-tracing approaches, we demonstrate that myeloid cells emerge from the endocardium in zebrafish embryos. Inhibition of Etv2/Etsrp or Scl/Tal1, two known master regulators of hematopoiesis and vasculogenesis, does not affect the emergence of endocardial-derived myeloid cells, while inhibition of Hedgehog signaling results in their reduction. Single-cell RNA sequencing analysis followed by experimental validation suggests that the endocardium is the major source of neutrophilic granulocytes. These findings will promote our understanding of alternative mechanisms involved in hematopoiesis, which are likely to be conserved between zebrafish and mammalian embryos.


Assuntos
Proteínas Hedgehog , Peixe-Zebra , Animais , Camundongos , Endocárdio , Células Sanguíneas , Embrião de Mamíferos , Mamíferos
14.
Nat Commun ; 15(1): 507, 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38218947

RESUMO

Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 µA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.


Assuntos
Marca-Passo Artificial , Suínos , Animais , Endocárdio , Próteses e Implantes , Eletricidade , Ventrículos do Coração
15.
Cell Mol Life Sci ; 81(1): 60, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38279064

RESUMO

Zebrafish have a remarkable ability to regenerate injured hearts. Altered hemodynamic forces after larval ventricle ablation activate the endocardial Klf2a-Notch signaling cascade to direct zebrafish cardiac regeneration. However, how the heart perceives blood flow changes and initiates signaling pathways promoting regeneration is not fully understood. The present study demonstrated that the mechanosensitive channel Trpv4 sensed the altered hemodynamic forces in injured hearts and its expression was regulated by blood flow. In addition to mediating the endocardial Klf2a-Notch signal cascade around the atrioventricular canal (AVC), we discovered that Trpv4 regulated nitric oxide (NO) signaling in the bulbus arteriosus (BA). Further experiments indicated that Notch signaling primarily acted at the early stage of regeneration, and the major role of NO signaling was at the late stage and through TGF-ß pathway. Overall, our findings revealed that mechanosensitive channels perceived the changes in hemodynamics after ventricle injury, and provide novel insights into the temporal and spatial coordination of multiple signaling pathways regulating heart regeneration.


Assuntos
Óxido Nítrico , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Óxido Nítrico/metabolismo , Coração , Endocárdio/metabolismo , Hemodinâmica , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
16.
Planta Med ; 90(2): 84-95, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37714195

RESUMO

A brand-new class of interstitial cells, called telocytes, has been detected in the heart. Telocytes can connect and transmit signals to almost all cardiomyocytes; this is highly interrelated with the occurrence and development of heart diseases. Modern studies have shown that berberine has a therapeutic effect on cardiovascular health. However, berberine's mechanism of action on the cardiovascular system through cardiac telocytes is unclear. Interestingly, 5 µm of berberine remarkably decreased the concentration of intracellular calcium and membrane depolarization in cultured telocytes, upregulated the expression of CX43 and ß-catenin, and downregulated the expressions of TRPV4 and TRPV1. Here, telocytes were identified in the vascular adventitia and intima, endocardium, myocardium, adventitia, and heart valves. Moreover, telocytes were broadly dispersed around cardiac vessels and interacted directly through gap junctions and indirectly through extracellular vesicles. Together, cardiac telocytes interact with berberine and then deliver drug information to the heart. Telocytes may be an essential cellular target for drug therapy of the cardiovascular system.


Assuntos
Berberina , Telócitos , Animais , Coelhos , Berberina/farmacologia , Miocárdio/metabolismo , Telócitos/metabolismo , Endocárdio/metabolismo , Miócitos Cardíacos
17.
J Electrocardiol ; 82: 27-33, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38000150

RESUMO

Background Electrical activity underlying the T-wave is less well understood than the QRS-complex. This study investigated the relationship between normal T-wave morphology and the underlying ventricular repolarization gradients using the equivalent dipole layer (EDL). Methods Body-surface-potential-maps (BSPM, 67­leads) were obtained in nine normal cases. Subject specific MRI-based anatomical heart/torso-models with electrode positions were created. The boundary element method was used to account for the volume conductor effects. To simulate the measured T-waves, the EDL was used to apply different ventricular repolarization gradients: a) transmural, b) interventricular c) apico-basal and d) all three gradients (a-c) combined. The combined gradient (d) was optimized using an inverse procedure (Levenberg-Marquardt). Correspondence between simulated and measured T-waves was assessed using correlation coefficient (CC) and relative difference (RD). Results Realistic T-waves were simulated if repolarization times of: (a) the epicardium were smaller than the endocardium; (b) the left ventricle were smaller than the right ventricle and (c) the apex increased towards the base. The apico-basal gradient resulted in the highest correspondence between measured and simulated T-waves (CC = 0.84(0.81-0.91);RD = 0.68(0.60-0.71)) compared to a transmural gradient (CC = 0.77(0.71-0.80);RD = 1.46(0.82-1.75)) and an interventricular gradient (CC = 0.71(0.67-0.80);RD = 0.85(0.75-0.87)). All three gradients combined further improved the correspondence between measured and simulated T-waves (CC = 0.83(0.82-0.89);RD = 0.60(0.51-0.63)), especially after optimization (CC = 0.96(0.94-0.98);RD = 0.27(0.22-0.34)). Conclusion The application of all repolarization gradients combined resulted in the largest agreement between simulated and measured T-waves, followed by the apico-basal repolarization gradient. With these findings, we will optimize our EDL-based inverse procedure to assess repolarization abnormalities.


Assuntos
Eletrocardiografia , Sistema de Condução Cardíaco , Humanos , Eletrocardiografia/métodos , Potenciais de Ação , Pericárdio , Endocárdio , Arritmias Cardíacas
18.
J Interv Card Electrophysiol ; 67(1): 1-3, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37991668

RESUMO

A previous study reported primary macroreentrant atrial tachycardia (AT) in the left atrium (LA), including the epicardial circuit on a left atrial anterior wall (LAAW) scar, without any prior cardiac intervention (Miyazawa et al. in J Cardiovasc Electrophysiol 2019; 30: 263-264). However, determining the target for terminating macroreentrant ATs is challenging. The mapping revealed a centrifugal pattern but did not fully elucidate the AT circuit. The reentrant mechanism of these ATs was confirmed using entrainment pacing. The earliest excitation site (EES) was traditionally selected as the ablation site, typically located in healthy tissue. However, our two cases provide new insights into AT termination, including the epicardial bridge across the endocardial LAAW scar, using minimum ablation points, without the need to ablate the healthy EES.


Assuntos
Ablação por Cateter , Taquicardia Supraventricular , Humanos , Cicatriz , Taquicardia Supraventricular/cirurgia , Átrios do Coração/cirurgia , Endocárdio/cirurgia
19.
JACC Clin Electrophysiol ; 10(1): 43-55, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37855769

RESUMO

BACKGROUND: Ventricular tachycardia (VT) associated with primary cardiac tumors (PCTs) originating from the ventricles is rare, but lethal, in young patients. OBJECTIVES: This study aimed to clarify the mechanisms underlying primary cardiac tumor-related ventricular tachycardia (PCT-VT) and establish a therapeutic strategy for this form of VT. METHODS: Among 67 patients who underwent surgery for VT at our institute between 1981 and 2020, 4 patients aged 1 to 34 years, including 3 males, showed PCT-VT (fibroma, 2; lipoma, 1; and hamartoma, 1), which was investigated using a combination of intraoperative electroanatomical mapping and histopathological studies. RESULTS: All 4 patients developed electrical storms of sustained VTs refractory to multiple drugs and repetitive endocardial ablations. The VT mechanism was re-entry, and intraoperative electroanatomical mapping showed a centrifugal activation pattern originating from the border between the tumor and healthy myocardium, where fractionated potentials were detected during sinus rhythm. Histopathological studies of serial sections of specimens acquired from these areas revealed tumor infiltration into the surrounding myocardium with cell disorganization, exhibiting myocardial disarray. Several myocardia entrapped in the tumor edges contributed to the development and sustainment of re-entrant VT activation. In the 2 patients in whom complete resection was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing VT occurrence. CONCLUSIONS: The mechanism underlying PCT-VT involves re-entry localized at the tumor edges. Myocardial disarray associated with tumor infiltration is a substrate for this form of VT. Cryoablation along the border between the tumor and myocardium is a promising therapeutic option for unresectable PCT-VT.


Assuntos
Neoplasias Cardíacas , Taquicardia Ventricular , Masculino , Humanos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/cirurgia , Ventrículos do Coração , Miocárdio , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/cirurgia , Endocárdio
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