RESUMEN
AIMS: Although patients with heart failure (HF) frequently experience considerable symptom burden and require significant care, most HF patients do not receive timely intervention due to the absence of a standardized method for identifying those in need of palliative care. The Needs Assessment Tool: Progressive Disease-Heart Failure (NAT: PD-HF) assesses the palliative care needs of patients with HF. However, its validity and reliability have yet to be fully examined. We aimed to assess the validity and reliability of the NAT: PD-HF in Japanese patients with HF. METHODS: We prospectively enrolled 106 consecutive patients with chronic HF admitted to our university hospital between February 2023 and July 2023. Their caregivers (n = 95) and healthcare providers (n = 17) were also included. The NAT: PD-HF was translated from English to Japanese using a forward-backward translation procedure and adapted based on Japanese cultural and medical backgrounds by our professional multidisciplinary team. We assessed the internal consistency of the Japanese NAT: PD-HF version with Cronbach's alpha coefficient and the inter-rater and test-retest reliabilities with Cohen's kappa coefficient. After using the tool, all participants were asked to complete a questionnaire about the tool to determine its validity. RESULTS: The proportion of female patients in this study was 47 (44%). The median age was 72 years [interquartile range (IQR) 59-81]. The median time spent assessing the patients' and their caregivers' needs using the Japanese NAT: PD-HF was 14 min (IQR 12-17). The Cronbach's alpha coefficient was 0.82, and the minimum kappa coefficient was 0.77 for inter-rater reliability and 0.88 for test-retest reliability. In total, 103 patients (97%) and all caregivers responded that the tool was easy to understand. One hundred (94%) patients and 89 (94%) caregivers felt that the tool would improve the quality of care, and 102 (96%) patients and 91 (96%) caregivers indicated that the discussions using this tool allowed them to confide in all their burdens and care needs. All healthcare providers expressed that this tool is helpful in understanding the burden and care needs of both patients and caregivers comprehensively. CONCLUSIONS: The NAT: PD-HF is a reliable and valid tool for Japanese patients with HF and their caregivers. This tool was very well accepted by patients, caregivers and healthcare providers to identify burdens and care needs.
Asunto(s)
Cardiomiopatías , Medios de Contraste , Fluorodesoxiglucosa F18 , Valor Predictivo de las Pruebas , Radiofármacos , Sarcoidosis , Humanos , Sarcoidosis/diagnóstico por imagen , Fluorodesoxiglucosa F18/administración & dosificación , Radiofármacos/administración & dosificación , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/fisiopatología , Medios de Contraste/administración & dosificación , Pronóstico , Persona de Mediana Edad , Femenino , Masculino , Miocardio/patología , Miocardio/metabolismo , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Imagen Multimodal , Adulto , Factores de Tiempo , AncianoRESUMEN
Epicardial adipose tissue (EAT) is an active endocrine organ that is closely associated with occurrence of atrial fibrillation (AF). However, the role of EAT in the development of postoperative AF (POAF) remains unclear. We aimed to investigate the association between EAT profile and POAF occurrence in patients who underwent cardiovascular surgery. We obtained EAT samples from 53 patients to evaluate gene expression, histological changes, mitochondrial oxidative phosphorylation (OXPHOS) capacity in the EAT, and protein secretion in EAT-conditioned medium. EAT volume was measured using computed tomography scan. Eighteen patients (34%) experienced POAF within 7 days after surgery. Although no significant difference was observed in EAT profile between patients with and without POAF, logistic regression analysis identified that the mRNA expression levels of tumor necrosis factor-alpha (TNF-α) were positively correlated and adipocyte size in the EAT was inversely correlated with onset of POAF, respectively. Mitochondrial OXPHOS capacity in the EAT was not associated with POAF occurrence; however, it showed an inverse correlation with adipocyte size and a positive correlation with adiponectin secretion. In conclusion, changes in the secretory profile and adipocyte morphology of the EAT, which represent qualitative aspects of the adipose tissue, were present before the onset of AF.
Asunto(s)
Fibrilación Atrial , Humanos , Fibrilación Atrial/metabolismo , Tejido Adiposo Epicárdico , Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Inflamación/metabolismo , Pericardio/metabolismoRESUMEN
AIMS: The most efficient way to acutely restore sinus rhythm from atrial fibrillation (AF) is electrical cardioversion, which is painful without adequate sedation. Recent studies in various experimental models have indicated that optogenetic termination of AF using light-gated ion channels may provide a myocardium-specific and potentially painless alternative future therapy. However, its underlying mechanism(s) remain(s) incompletely understood. As brief pulsed light stimulation, even without global illumination, can achieve optogenetic AF termination, besides direct conduction block also modulation of action potential (AP) properties may be involved in the termination mechanism. We studied the relationship between optogenetic AP duration (APD) and effective refractory period (ERP) prolongation by brief pulsed light stimulation and termination of atrial tachyarrhythmia (AT). METHODS AND RESULTS: Hearts from transgenic mice expressing the H134R variant of channelrhodopsin-2 in atrial myocytes were explanted and perfused retrogradely. AT induced by electrical stimulation was terminated by brief pulsed blue light stimulation (470 nm, 10 ms, 16 mW/mm2) with 68% efficacy. The termination rate was dependent on pulse duration and light intensity. Optogenetically imposed APD and ERP changes were systematically examined and optically monitored. Brief pulsed light stimulation (10 ms, 6 mW/mm2) consistently prolonged APD and ERP when light was applied at different phases of the cardiac action potential. Optical tracing showed light-induced APD prolongation during the termination of AT. CONCLUSION: Our results directly demonstrate that cationic channelrhodopsin activation by brief pulsed light stimulation prolongs the atrial refractory period suggesting that this is one of the key mechanisms of optogenetic termination of AT.
Asunto(s)
Fibrilación Atrial , Animales , Ratones , Fibrilación Atrial/terapia , Optogenética/métodos , Channelrhodopsins/genética , Atrios Cardíacos , Taquicardia , Ratones Transgénicos , Potenciales de AcciónRESUMEN
Introduction: Recent studies have demonstrated that sodium-glucose co-transporter-2 inhibitors (SGLT2-i) reduce the risk of atrial fibrillation (AF) in patients with diabetes mellitus (DM), in which oxidative stress due to increased reactive oxygen species (ROS) contributes to the pathogenesis of AF. We aimed to further investigate this, and examine whether the SGLT2-i empagliflozin suppresses mitochondrial-ROS generation and mitigates fibrosis. Methods: A high-fat diet and low-dose streptozotocin treatment were used to induce type-2 DM (T2DM) in Sprague-Dawley rats. The rats were randomly divided into three groups: control, DM, and DM treated with empagliflozin (30 mg/kg/day) for 8 weeks. The mitochondrial respiratory capacity and ROS generation in the atrial myocardium were measured using a high-resolution respirometer. Oxidative stress markers and protein expression related to mitochondrial biogenesis and dynamics as well as the mitochondrial morphology were examined in the atrial tissue. Additionally, mitochondrial function was examined in H9c2 cardiomyoblasts. Atrial tachyarrhythmia (ATA) inducibility, interatrial conduction time (IACT), and fibrosis were also measured. Results: Inducibility of ATA, fibrosis, and IACT were increased in rats with DM when compared to controls, all of which were restored by empagliflozin treatment. In addition, the rats with DM had increased mitochondrial-ROS with an impaired complex I-linked oxidative phosphorylation capacity. Importantly, empagliflozin seemed to ameliorate these impairments in mitochondrial function. Furthermore, empagliflozin reversed the decrease in phosphorylated AMPK expression and altered protein levels related to mitochondrial biogenesis and dynamics, and increased mitochondrial content. Empagliflozin also improved mitochondrial function in H9c2 cells cultured with high glucose medium. Discussion: These data suggest that empagliflozin has a cardioprotective effect, at least in part, by reducing mitochondrial ROS generation through AMPK signaling pathways in the atrium of diabetic rats. This suggests that empagliflozin might suppress the development of AF in T2DM.
RESUMEN
Diabetic cardiomyopathy has been reported to increase the risk of fatal ventricular arrhythmia. The beneficial effects of the selective sodium-glucose cotransporter-2 inhibitor have not been fully examined in the context of antiarrhythmic therapy, especially its direct cardioprotective effects despite the negligible SGLT2 expression in cardiomyocytes. We aimed to examine the antiarrhythmic effects of empagliflozin (EMPA) treatment on diabetic cardiomyocytes, with a special focus on Ca2+ handling. We conducted echocardiography and hemodynamic studies and studied electrophysiology, Ca2+ handling, and protein expression in C57BLKS/J-leprdb/db mice (db/db mice) and their nondiabetic lean heterozygous Leprdb/+ littermates (db/+ mice). Preserved systolic function with diastolic dysfunction was observed in 16-wk-old db/db mice. During arrhythmia induction, db/db mice had significantly increased premature ventricular complexes (PVCs) than controls, which was attenuated by EMPA. In protein expression analyses, calmodulin-dependent protein kinase II (CaMKII) Thr287 autophosphorylation and CaMKII-dependent RyR2 phosphorylation (S2814) were significantly increased in diabetic hearts, which were inhibited by EMPA. In addition, global O-GlcNAcylation significantly decreased with EMPA treatment. Furthermore, EMPA significantly inhibited ventricular cardiomyocyte glucose uptake. Diabetic cardiomyocytes exhibited increased spontaneous Ca2+ events and decreased sarcoplasmic reticulum (SR) Ca2+ content, along with impaired Ca2+ transient, all of which normalized with EMPA treatment. Notably, most EMPA-induced improvements in Ca2+ handling were abolished by the addition of an O-GlcNAcase (OGA) inhibitor. In conclusion, EMPA attenuated ventricular arrhythmia inducibility by normalizing the intracellular Ca2+ handling, and we speculated that this effect was, at least partly, due to the inhibition of O-GlcNAcylation via the suppression of glucose uptake into cardiomyocytes.NEW & NOTEWORTHY SGLT2is are known to improve cardiovascular outcomes regardless of the presence of diabetes and decrease traditional cardiovascular risk factors. We demonstrated, for the first time, that EMPA inhibited PVCs by normalizing Ca2+ handling in diabetic mice. Our data suggest that the effects of SGLT2is on calcium handling may occur because of suppression of O-GlcNAcylation through inhibition of glucose uptake and not because of NHE inhibition, as previously suggested.
Asunto(s)
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Cardiomiopatías Diabéticas , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Ratones , Animales , Miocitos Cardíacos/metabolismo , Cardiomiopatías Diabéticas/tratamiento farmacológico , Cardiomiopatías Diabéticas/etiología , Cardiomiopatías Diabéticas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Arritmias Cardíacas/tratamiento farmacológico , Arritmias Cardíacas/etiología , Arritmias Cardíacas/prevención & control , Glucosa/metabolismo , Calcio/metabolismoRESUMEN
BACKGROUND: Mapping techniques to identify diseased myocardial substrate during ventricular tachycardia ablation procedures remain limited. OBJECTIVE: We hypothesized that tissue derivative of the voltage with respect to time (dV/dt), the slope of the unipolar ventricular electrogram registered by local ventricular activation, represents a unique parameter for identifying potential arrhythmogenic tissue in the ischemic scar border zone. METHODS: Using high-resolution electrical mapping, we examined dV/dt characteristics in the border zone of animals after chronic myocardial infarction (MI). RESULTS: Minimum dV/dt (dV/dtmin) in MI animals was less than that in control animals (-344.7 ± 68.7 in controls vs -174.2 ± 104.5 in MI; P < .001) and related to ventricular fibrosis. In MI animals, dV/dtmin values were divided into high (≤-200 µV/ms) and low (>-200 µV/ms) dV/dtmin. Low dV/dtmin regions harbored arrhythmogenic substrates that were characterized by (1) high responsiveness to sympathetic stimulation, (2) presence of late potentials, and (3) lower unipolar and bipolar voltage amplitudes. CONCLUSION: Our data indicate that dV/dtmin is a unique parameter for identifying arrhythmogenic myocardium and may add a useful metric to conventional mapping strategies.
Asunto(s)
Ablación por Catéter , Infarto del Miocardio , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiología , Taquicardia Ventricular/cirugía , Miocardio , Ventrículos Cardíacos , Arritmias Cardíacas , Ablación por Catéter/métodosRESUMEN
Stellate ganglia within the intrathoracic cardiac control system receive and integrate central, peripheral, and cardiopulmonary information to produce postganglionic cardiac sympathetic inputs. Pathological anatomical and structural remodeling occurs within the neurons of the stellate ganglion (SG) in the setting of heart failure (HF). A large proportion of SG neurons function as interneurons whose networking capabilities are largely unknown. Current therapies are limited to targeting sympathetic activity at the cardiac level or surgical interventions such as stellectomy, to treat HF. Future therapies that target the SG will require understanding of their networking capabilities to modify any pathological remodeling. We observe SG networking by examining cofluctuation and specificity of SG networked activity to cardiac cycle phases. We investigate network processing of cardiopulmonary transduction by SG neuronal populations in porcine with chronic pacing-induced HF and control subjects during extended in-vivo extracellular microelectrode recordings. We find that information processing and cardiac control in chronic HF by the SG, relative to controls, exhibits: (i) more frequent, short-lived, high magnitude cofluctuations, (ii) greater variation in neural specificity to cardiac cycles, and (iii) neural network activity and cardiac control linkage that depends on disease state and cofluctuation magnitude.
Asunto(s)
Insuficiencia Cardíaca , Ganglio Estrellado , Animales , Porcinos , Ganglio Estrellado/fisiología , Ganglio Estrellado/cirugía , Benchmarking , Entropía , CorazónRESUMEN
Atrial fibrillation (AF) is associated with electrical remodeling processes that promote a substrate for the maintenance of AF. Although the small-conductance Ca2+-activated K+ (SK) channel is a key factor in atrial electrical remodeling, the mechanism of its activation remains unclear. Regional nitric oxide (NO) production by neuronal nitric oxide synthase (nNOS) is involved in atrial electrical remodeling. In this study, atrial tachyarrhythmia (ATA) induction and optical mapping were performed on perfused rat hearts. nNOS is pharmacologically inhibited by S-methylthiocitrulline (SMTC). The influence of the SK channel was examined using a specific channel inhibitor, apamin (APA). Parameters such as action potential duration (APD), conduction velocity, and calcium transient (CaT) were evaluated using voltage and calcium optical mapping. The dominant frequency was examined in the analysis of AF dynamics. SMTC (100 nM) increased the inducibility of ATA and apamin (100 nM) mitigated nNOS inhibition-induced arrhythmogenicity. SMTC caused abbreviations and enhanced the spatial dispersion of APD, which was reversed by apamin. By contrast, conduction velocity and other parameters associated with CaT were not affected by SMTC or apamin administration. Apamin reduced the frequency of SMTC-induced ATA. In summary, nNOS inhibition abbreviates APD by modifying the SK channels. A specific SK channel blocker, apamin, mitigated APD abbreviation without alteration of CaT, implying an underlying mechanism of posttranslational modification of SK channels.NEW & NOTEWORTHY We demonstrated that pharmacological nNOS inhibition increased the atrial arrhythmia inducibility and a specific small-conductance Ca2+-activated K+ channel blocker, apamin, reversed the enhanced atrial arrhythmia inducibility. Apamin mitigated APD abbreviation without alteration of Ca2+ transient, implying an underlying mechanism of posttranslational modification of SK channels.
Asunto(s)
Fibrilación Atrial , Remodelación Atrial , Animales , Apamina/farmacología , Calcio/metabolismo , Óxido Nítrico , Óxido Nítrico Sintasa de Tipo I , Ratas , Canales de Potasio de Pequeña Conductancia Activados por el CalcioRESUMEN
BACKGROUND: An aberrant increase in the diastolic calcium concentration ([Ca2+]i) level is a hallmark of heart failure (HF) and the cause of delayed afterdepolarization and ventricular arrhythmia (VA). Although mitochondria play a role in regulating [Ca2+]i, whether they can compensate for the [Ca2+]i abnormality in ventricular myocytes is unknown. OBJECTIVE: The purpose of this study was to investigate whether enhanced Ca2+ uptake of mitochondria may compensate for an abnormal increase in the [Ca2+]i of ventricular myocytes in HF to effectively mitigate VA. METHODS: We used a HF mouse model in which myocardial infarction was induced by permanent left anterior descending coronary artery ligation. The mitochondrial Ca2+ uniporter was stimulated by kaempferol. Ca2+ dynamics and membrane potential were measured using an epifluorescence microscope, a confocal microscope, and the perforated patch-clamp technique. VA was induced in Langendorff-perfused hearts, and hemodynamic parameters were measured using a microtip transducer catheter. RESULTS: Protein expression of the mitochondrial Ca2+ uniporter, as assessed by its subunit expression, did not change between HF and sham mice. Treatment of cardiomyocytes with kaempferol, isolated from HF mice 28 days after coronary ligation, reduced the appearance of aberrant diastolic [Ca2+]i waves and sparks and spontaneous action potentials. Kaempferol effectively reduced VA occurring in Langendorff-perfused hearts. Intravenous administration of kaempferol did not markedly affect left ventricular hemodynamic parameters. CONCLUSION: The effects of kaempferol in HF of mice implied that mitochondria may have the potential to compensate for abnormal [Ca2+]i. Mechanisms involved in mitochondrial Ca2+ uptake may provide novel targets for treatment of HF-associated VA.
Asunto(s)
Calcio , Insuficiencia Cardíaca , Animales , Arritmias Cardíacas , Calcio/metabolismo , Canales de Calcio , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/etiología , Quempferoles/metabolismo , Quempferoles/farmacología , Ratones , Miocitos Cardíacos/metabolismoRESUMEN
BACKGROUND: Electrical storms (ESs) in patients with structural heart disease (SHD) have been reported to be associated with a poor prognosis. However, the detailed cause of death and influence of implantable cardioverter defibrillator (ICD) therapy in ES patients have not been fully investigated. Therefore, we sought to explore the detailed clinical course after an ES and the impact of the ICD therapy in patients with SHDs. METHODS: We retrospectively analyzed 31 consecutive patients with ESs who had undergone an ICD implantation. ESs were defined as three or more ventricular arrhythmias within 24â¯h. RESULTS: During a mean follow up of 4.5â¯years, 13 patients died. Among them, cardiovascular death (CVD) was observed in 11/13 (85%), and the leading cause of the CVD was end-stage heart failure. A New York Heart Association class ≥III at the time of the ES occurrence (HR 6.51 95% CI 1.94-25.1, pâ¯=â¯0.003) and any shock therapy (HR 5.94 95% CI 1.06-112.2, pâ¯=â¯0.04) were associated with CVD. CONCLUSION: In the current single center study, the major cause of death in ES patients with SHDs was end-stage heart failure. Any shock therapy was associated with CVD. Arrhythmia management to avoid ICD shocks might reduce the mortality in ES patients.
Asunto(s)
Desfibriladores Implantables , Insuficiencia Cardíaca , Taquicardia Ventricular , Desfibriladores Implantables/efectos adversos , Humanos , Estudios Retrospectivos , Taquicardia Ventricular/etiología , Taquicardia Ventricular/terapia , Fibrilación Ventricular/etiología , Fibrilación Ventricular/terapiaRESUMEN
BACKGROUND: Clinical trials for renal artery (RA) ablation have shown limited efficacy. OBJECTIVE: The purpose of this study was to investigate whether the aorticorenal ganglion (ARG) can be targeted for renal denervation. METHODS: Twenty-eight pigs were studied under isoflurane or alpha-chloralose to examine hemodynamic responses and catecholamine release in response to RA or ARG stimulation. To assess the efficacy of ARG ablation, we randomized 16 pigs to either sham, RA, or ARG ablation, followed by occlusion of the left anterior descending coronary artery (LAD). Hemodynamic responses, cardiac electrophysiological parameters, and arrhythmias/sudden cardiac death were assessed following LAD occlusion. Absent hemodynamic responses to stimulation confirmed ARG or RA ablation. In vivo stellate ganglion neural activity was recorded to assess cardiac sympathetic signaling. Cadaveric dissections were performed to localize the ARG in humans for comparison to swine. RESULTS: The ARG is a purely sympathetic ganglion with cholinergic inputs and pass-through sensory afferent fibers. Compared to RA stimulation, ARG stimulation yielded greater hemodynamic responses during alpha-chloralose anesthesia. However, neither site yielded significant responses under isoflurane. Radiofrequency ablation of the ARG eliminated responses to both RA and ARG stimulation, whereas RA ablation did not eliminate responses to ARG stimulation. Ablation of the ARG did not impact the kidneys or adrenal glands. Compared to control and RA ablation, ARG ablation was protective against ventricular arrhythmias and sudden death. Human and swine ARG are similarly located in the aorticorenal region. CONCLUSION: Our findings indicate that the ARG may be a novel target for renal neuromodulation. Further studies are warranted to validate these findings.
Asunto(s)
Arritmias Cardíacas/terapia , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Riñón/inervación , Ganglio Estrellado/cirugía , Simpatectomía/métodos , Animales , Arritmias Cardíacas/fisiopatología , Modelos Animales de Enfermedad , Femenino , Masculino , Ganglio Estrellado/fisiopatología , PorcinosRESUMEN
BACKGROUND: The mechanisms underlying premature ventricular contraction (PVC)-induced cardiomyopathy (PIC) remain unknown. Transient receptor potential vanilloid-1 (TRPV1) afferent fibers are implicated in the reflex processing of cardiac stress. OBJECTIVE: The purpose of this study was to determine whether cardiac TRPV1 afferent signaling promote PIC. METHODS: A PIC swine model (50% PVC burden) was created via an implanted pacemaker. We selectively depleted cardiac TRPV1 afferent fibers using percutaneous epicardial application of resiniferatoxin (RTX). Animals were randomized to PVC only (n = 11), PVC+RTX (n = 11), or control (n = 6). We examined early-stage (4 weeks after implantation; n = 5) and late-stage PIC (8 weeks after implantation; n = 6). At terminal experimentation, animals underwent echocardiography, serum sampling, and physiological and autonomic reflex testing. RESULTS: Depletion of cardiac TRPV1 afferents by RTX treatment was confirmed by absent sensory fibers and absent functional responses to TRPV1 activators. Left ventricular ejection fraction was worse in late-stage than early-stage PIC (P <.01). At 4 weeks (early stage), left ventricular ejection fraction was higher in PVC+RTX vs PVC animals (51.7% ± 1.6% vs 45.0% ± 2.1%; P = .030), whereas no significant difference between PVC and PVC+RTX was observed at 8 weeks (late stage). Histologic studies demonstrated reduced fibrosis in PVC+RTX vs PVC alone at 4 weeks (2.27% ± 0.14% vs 3.01% ± 0.21%; P = .020), suggesting that RTX mitigated profibrotic pathways induced by persistent PVCs. CONCLUSION: TRPV1 afferent depletion alleviates left ventricular dysfunction in early- but not late-stage PIC. This temporal effect suggests that multiple pathways promote PIC, of which TRPV1 afferents are a part.
Asunto(s)
Vías Aferentes/fisiopatología , Cardiomiopatías , Corazón/inervación , Transducción de Señal , Canales Catiónicos TRPV/agonistas , Complejos Prematuros Ventriculares , Animales , Cardiomiopatías/etiología , Cardiomiopatías/patología , Cardiomiopatías/fisiopatología , Diterpenos/farmacología , Ecocardiografía/métodos , Fibrosis , Modelos Animales , Neurotoxinas/farmacología , Volumen Sistólico , Porcinos , Función Ventricular Izquierda , Complejos Prematuros Ventriculares/complicaciones , Complejos Prematuros Ventriculares/fisiopatologíaRESUMEN
Ventricular arrhythmia (VA) is the major cause of death in patients with left ventricular (LV) hypertrophy and/or acute ischemia. We hypothesized that apamin, a blocker of small-conductance Ca2+-activated K+ (SK) channels, alters Ca2+ handling and exhibits anti-arrhythmic effects in ventricular myocardium. Spontaneous hypertensive rats were used as a model of LV hypertrophy. A dual optical mapping of membrane potential (Vm) and intracellular calcium (Cai) was performed during global hypoxia (GH) on the Langendorff perfusion system. The majority of pacing-induced VAs during GH were initiated by triggered activities. Pretreatment of apamin (100 nmol/L) significantly inhibited the VA inducibility. Compared with SK channel blockers (apamin and NS8593), non-SK channel blockers (glibenclamide and 4-AP) did not exhibit anti-arrhythmic effects. Apamin prevented not only action potential duration (APD80) shortening (-18.7 [95% confidence interval, -35.2 to -6.05] ms vs. -2.75 [95% CI, -10.45 to 12.65] ms, P = 0.04) but also calcium transient duration (CaTD80) prolongation (14.52 [95% CI, 8.8-20.35] ms vs. 3.85 [95% CI, -3.3 to 12.1] ms, P < 0.01), thereby reducing CaTD80 - APD80, which denotes "Cai/Vm uncoupling" (33.22 [95% CI, 22-48.4] ms vs. 6.6 [95% CI, 0-14.85] ms, P < 0.01). The reduction of Cai/Vm uncoupling was attributable to less prolonged Ca2+ decay constant and suppression of diastolic Cai increase by apamin. The inhibition of VA inducibility and changes in APs/CaTs parameters caused by apamin was negated by the addition of ouabain, an inhibitor of Na+/K+ pump. Apamin attenuates APD shortening, Ca2+ handling abnormalities, and Cai/Vm uncoupling, leading to inhibition of VA occurrence in hypoxic hypertrophied hearts.NEW & NOTEWORTHY We demonstrated that hypoxia-induced ventricular arrhythmias were mainly initiated by Ca2+-loaded triggered activities in hypertrophied hearts. The blockades of small-conductance Ca2+-activated K+ channels, especially "apamin," showed anti-arrhythmic effects by alleviation of not only action potential duration shortening but also Ca2+ handling abnormalities, most notably the "Ca2+/voltage uncoupling."
Asunto(s)
Antiarrítmicos/farmacología , Arritmias Cardíacas/prevención & control , Señalización del Calcio/efectos de los fármacos , Cardiomegalia/tratamiento farmacológico , Frecuencia Cardíaca/efectos de los fármacos , Hipoxia/tratamiento farmacológico , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/antagonistas & inhibidores , 1-Naftilamina/análogos & derivados , 1-Naftilamina/farmacología , Potenciales de Acción/efectos de los fármacos , Animales , Apamina/farmacología , Arritmias Cardíacas/etiología , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Estimulación Cardíaca Artificial , Cardiomegalia/complicaciones , Cardiomegalia/metabolismo , Cardiomegalia/fisiopatología , Modelos Animales de Enfermedad , Hipoxia/complicaciones , Hipoxia/metabolismo , Hipoxia/fisiopatología , Preparación de Corazón Aislado , Masculino , Ratas Endogámicas SHR , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/metabolismo , Factores de TiempoRESUMEN
Recurrence of atrial tachyarrhythmias (ATA) following catheter ablation for atrial fibrillation (AF) is often associated with the recovery of conduction into previously isolated pulmonary veins (PVs). Little evidence concerning repeat PV isolation (PVI) and non-PV ATA ablation has been reported. This study aimed to explore the clinical outcome of recurrent ATA ablation after PVI and the difference between patients with and without non-PV ATA.A total of 49 patients without structural heart diseases who received catheter ablation for recurrent AF between January 2014 and December 2018 were recruited (prior ablation with PVI only 71.4% and PVI with cavotricuspid isthmus line ablation 28.6%). Patients were divided into two groups according to the presence or absence of non-PV ATA.Most patients (53.1%) experienced very late recurrence with a median duration of 15 months. A total of 15 patients had non-PV ATA and received non-PV ATA ablation whereas 34 patients received only repeat PVI for reconnected PVs. A higher pulmonary arterial systolic pressure (PASP) was associated with non-PV ATA (odds ratio: 1.161; 95% confidence interval: 1.021-1.321; P = 0.023). During 4.7 ± 1 months, 4/15 (26.7%) and 1/34 (2.9%) patients with and without non-PV ATA, respectively, had ATA recurrence (P = 0.011). The cumulative incidence of ATA recurrence after repeat ablation was significantly lower in patients without non-PV ATA (P = 0.013).In our study, a high PASP was associated with non-PV ATA in patients with recurrent AF. Repeat PVI had a high rate of maintenance of sinus rhythm in patients without non-PV ATA.
Asunto(s)
Presión Arterial , Fibrilación Atrial/cirugía , Ablación por Catéter , Arteria Pulmonar/fisiopatología , Venas Pulmonares/cirugía , Taquicardia Atrial Ectópica/epidemiología , Anciano , Fibrilación Atrial/epidemiología , Aleteo Atrial , Ecocardiografía , Femenino , Humanos , Incidencia , Modelos Logísticos , Masculino , Recurrencia , Factores de Riesgo , Factores SexualesRESUMEN
AIMS: Nonsustained ventricular tachycardia (NSVT) occurs frequently in patients with dilated cardiomyopathy (DCM), especially in high-risk patients. The role of rapid-rate NSVT (RR-NSVT) documented by an implantable cardioverter-defibrillator (ICD) in DCM patients has not been fully explored. This study aimed to determine the relationship between RR-NSVT and the occurrence of ventricular tachyarrhythmias (VTAs) in DCM patients with ICD. METHODS: From December 2000 to December 2017, 136 DCM patients received ICD or cardiac resynchronization therapy defibrillator (CRT-D) implantation for primary or secondary prevention of VTAs. Based on the occurrence of documented RR-NSVT, patients were classified into RR-NSVT (-) or RR-NSVT (+) groups. RESULT: During the median follow-up of 4.5 years, 50.0% (68/136) patients experienced ≥1 episode, and 25.0% (34/136) patients experienced ≥3 episodes of RR-NSVT. Event-free survival for VTAs was significantly higher in the RR-NSVT (-) group, whereas those for heart failure admission and cardiovascular mortality were comparable between groups. In the multivariate Cox regression analysis, any RR-NSVT showed a positive association with the occurrence of VTAs (hazard ratio: 5.087; 95% confidence interval: 2.374-10.900; P < .001). In RR-NSVT (+) patients, a cluster (≥3 times/6 months) and frequent pattern (≥3 runs/day) of RR-NSVT were observed in 42.6% (29/68) and 30.9% (21/68) patients, respectively, who showed further increased incidence of VTAs. CONCLUSION: In DCM patients with ICD/CRT-D, 50.0% patients experienced at least one episode of RR-NSVT. RR-NSVT documentation showed a positive association with subsequent occurrence of VTAs, suggesting the importance of constructive arrhythmia management for patients with RR-NSVT.
Asunto(s)
Cardiomiopatía Dilatada/complicaciones , Desfibriladores Implantables , Taquicardia Ventricular/etiología , Taquicardia Ventricular/prevención & control , Cardiomiopatía Dilatada/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Taquicardia Ventricular/fisiopatologíaRESUMEN
Epirubicin-based chemotherapy carries a risk of inducing heart failure, although the frequency is rare. Bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, has recently been widely used in patients with recurrent breast cancer as a first-line chemotherapeutic agent. Heart failure or arterial thromboembolism has been reported as a rare cardiovascular complication of bevacizumab. We herein report a breast cancer patient with reversible cancer therapeutics-related cardiac dysfunction associated with bevacizumab and epirubicin complicating intracardiac thrombi in the left atrium and left ventricle. This case underscores the importance of tailored medical planning according to the individual status in patients receiving anti-cancer therapies.
Asunto(s)
Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Bevacizumab/efectos adversos , Neoplasias de la Mama/tratamiento farmacológico , Epirrubicina/efectos adversos , Insuficiencia Cardíaca/inducido químicamente , Insuficiencia Cardíaca/tratamiento farmacológico , Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bevacizumab/uso terapéutico , Epirrubicina/uso terapéutico , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Resultado del TratamientoRESUMEN
BACKGROUND: Atrial fibrillation (AF) is an important prognostic determinant in heart failure (HF) with preserved ejection fraction (HFpEF). However, it is unclear which HFpEF phenotypes are affected by AF in terms of long-term clinical outcomes because HFpEF is a heterogeneous syndrome with comorbidities such as coronary artery disease (CAD). In this study we determined the differential prognostic significance of AF in HFpEF patients according to CAD status.MethodsâandâResults:Data for 408 hospitalized HFpEF patients enrolled in the Japanese Heart Failure Syndrome with Preserved Ejection Fraction Nationwide Multicenter Registry were analyzed. Patients were divided into 4 groups according to the presence of AF and CAD. The primary outcome was the composite of all-cause death and HF rehospitalization. The incidence of adverse events was higher in the AF-non-CAD than non-AF-non-CAD group (P=0.004). On multivariable Cox regression analysis with prespecified confounders, AF-non-CAD was significantly associated with an increased risk of adverse events than non-AF-non-CAD (adjusted HR, 1.91; 95% CI: 1.02-3.92) regardless of the type of AF. In contrast, risk was comparable between the AF-CAD and non-AF-CAD groups (adjusted HR, 1.24; 95% CI: 0.64-2.47). CONCLUSIONS: In HFpEF patients without CAD, AF was independently related to adverse events, indicating that intensive management of AF would have more beneficial effects particularly in HFpEF patients without CAD.