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1.
Circ Cardiovasc Imaging ; 10(12)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29208596

RESUMEN

BACKGROUND: Recently, we reported that urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), an oxidative stress marker, reflected inflammatory activity in cardiac sarcoidosis (CS). Here, we investigated whether U-8-OHdG levels were associated with ventricular tachycardia (VT) in patients with CS. METHODS AND RESULTS: This prospective cohort study enrolled 62 consecutive patients with CS, of whom 36 were diagnosed as having active CS based on abnormal 18F-flurodeoxyglucose accumulation in the heart on positron-emission tomography/computed tomography. The 36 patients with active CS were subdivided as having CS with sustained VT (CS-VT group; n=18) or CS without sustained VT (CS-nVT group; n=18). Twenty-seven patients diagnosed with idiopathic dilated cardiomyopathy served as heart failure controls. U-8-OHdG, brain natriuretic peptide, cardiac function indices, and immunohistological data from subendomyocardial biopsy samples were compared across groups. Immunohistochemical examination of ventricle biopsy samples revealed that the anti-8-OHdG antibody-positive area of cardiac tissue was significantly greater in CS-VT than in CS-nVT or dilated cardiomyopathy and significantly correlated with U-8-OHdG levels (n=58; R=0.61; P<0.00001), which were significantly higher in CS-VT than in CS-nVT (24.6±7.1 versus 15.2±3.8 ng/mg·Cr; P<0.0001). Other baseline characteristics did not differ between the groups. Multivariate analysis indicated that U-8-OHdG was an independent determinant factor for VT. Receiver operating characteristic curve analysis to identify patients with VT resulted in a U-8-OHdG cutoff value of 17.5 ng/mg·Cr (sensitivity, 89%; specificity, 83%; area under the curve, 0.90). CONCLUSIONS: U-8-OHdG levels are associated with VT in patients with active CS diagnosed by 18F-flurodeoxyglucose positron-emission tomography, providing additive and relevant information about the arrhythmia substrate.


Asunto(s)
Biomarcadores/orina , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/orina , Desoxiguanosina/análogos & derivados , Estrés Oxidativo , Sarcoidosis/diagnóstico por imagen , Sarcoidosis/orina , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/orina , 8-Hidroxi-2'-Desoxicoguanosina , Anciano , Cardiomiopatías/fisiopatología , Desoxiguanosina/orina , Ecocardiografía , Electrocardiografía , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Prospectivos , Radiofármacos , Sarcoidosis/fisiopatología , Taquicardia Ventricular/fisiopatología
2.
Heart Rhythm ; 14(1): 120-127, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27771553

RESUMEN

BACKGROUND: Calmodulin (CaM) is a key modulator of the channel gating function of the ryanodine receptor (RyR). OBJECTIVE: The purpose of this study was to investigate the pathogenic role of RyR-bound CaM in diastolic Ca2+ leakage from the sarcoplasmic reticulum and arrhythmogenesis in pressure-overloaded heart failure. METHODS: Pressure overload was induced in 12-week-old mice by transverse aortic constriction (TAC) using a 27-gauge needle. RESULTS: TAC operation for 8 weeks produced a significant increase in left ventricular end-diastolic diameter and frequent occurrence of lethal arrhythmias after infusion of epinephrine and caffeine in TAC mice. The amount of RyR-bound CaM decreased significantly in TAC mice compared with sham mice. The apparent affinity of CaM binding to RyR decreased in pressure-overloaded cells compared with sham cells and untreated cells. High-affinity calmodulin (HA-CaM; ie, CaM whose binding affinity to RyR was significantly increased) restored a normal level of CaM-RyR binding properties in pressure-overloaded cells. HA-CaM corrected abnormally increased Ca2+ spark frequency in the pressure-overloaded cells to the level seen in the sham cells. The frequency of spontaneous Ca2+ transients in TAC cells during and after 1-5 Hz of field stimulation was 44%, whereas it was significantly attenuated by HA-CaM but not with CaM. CONCLUSION: Several disorders in the RyR channel function characteristic of pressure-overloaded cells (increased spontaneous Ca2+ leakage, delayed afterdepolarization, triggered activity, Ca2+ spark frequency, spontaneous Ca2+ transients) are caused by deteriorated CaM binding to RyR2. These disorders could be rectified by restoring normal CaM binding to RyR2.


Asunto(s)
Calmodulina/metabolismo , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/terapia , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Taquicardia Ventricular/diagnóstico , Animales , Mapeo del Potencial de Superficie Corporal/métodos , Canales de Calcio/metabolismo , Señalización del Calcio , Células Cultivadas , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/mortalidad , Ratones , Ratones Endogámicos , Miocitos Cardíacos/metabolismo , Distribución Aleatoria , Valores de Referencia , Retículo Sarcoplasmático/metabolismo , Sensibilidad y Especificidad , Taquicardia Ventricular/mortalidad , Taquicardia Ventricular/terapia
3.
PLoS One ; 11(9): e0163250, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27657534

RESUMEN

Catecholamines induce intracellular reactive oxygen species (ROS), thus enhancing diastolic Ca2+ leakage through the ryanodine receptor during heart failure (HF). However, little is known regarding the effect of atrial natriuretic peptide (ANP) on ROS generation and Ca2+ handling in failing cardiomyocytes. The aim of the present study was to clarify the mechanism by which an exogenous ANP exerts cardioprotective effects during HF. Cardiomyocytes were isolated from the left ventricles of a canine tachycardia-induced HF model and sham-operated vehicle controls. The degree of mitochondrial oxidized DNA was evaluated by double immunohistochemical (IHC) staining using an anti-VDAC antibody for the mitochondria and an anti-8-hydroxy-2'-deoxyguanosine antibody for oxidized DNA. The effect of ANP on ROS was investigated using 2,7-dichlorofluorescin diacetate, diastolic Ca2+ sparks assessed by confocal microscopy using Fluo 4-AM, and the survival rate of myocytes after 48 h. The double IHC study revealed that isoproterenol (ISO) markedly increased oxidized DNA in the mitochondria in HF and that the ISO-induced DNA damage was markedly inhibited by the co-presence of ANP. ROS production and Ca2+ spark frequency (CaSF) were increased in HF compared to normal controls, and were further increased in the presence of ISO. Notably, ANP significantly suppressed both ISO-induced ROS and CaSF without changing sarcoplasmic reticulum Ca2+ content in HF (p<0.01, respectively). The survival rate after 48 h in HF was significantly decreased in the presence of ISO compared with baseline (p<0.01), whereas it was significantly improved by the co-presence of ANP (p<0.01). Together, our results suggest that ANP strongly suppresses ISO-induced mitochondrial ROS generation, which might correct aberrant diastolic Ca2+ sparks, eventually contributing to the improvement of cardiomyocyte survival in HF.

4.
Int J Cardiol ; 212: 206-13, 2016 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-27043062

RESUMEN

BACKGROUND: We investigated whether urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), a marker of oxidative DNA damage, is a prognosticator of cardiovascular-related death in patients with cardiac sarcoidosis (CS). METHODS AND RESULTS: In this prospective study, 30 consecutive patients were divided into the active CS (n=20) and non-active CS (n=10) groups, based on abnormal isotope accumulation in the heart on (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography ((18)F-FDG PET/CT) imaging. Nineteen patients in the active CS group underwent corticosteroid therapy. Before corticosteroid therapy initiation, U-8-OHdG, brain natriuretic peptide (BNP), other biomarkers, and indices of cardiac function were measured. Patients were followed-up for a median of 48months. The primary endpoint was the incidence of cardiovascular-related death. During the follow-up period, in the corticosteroid-treated active CS group, 7 of 19 patients experienced cardiovascular-related death. By contrast, in the non-active CS group, 1 of 10 patients died from cardiovascular-related causes. Univariate and multivariate analyses showed that U-8-OHdG and BNP were independent predictors for cardiovascular-related death. The cut-off values for predicting cardiovascular death in corticosteroid-treated patients with active CS were 19.1ng/mg·Cr and 209pg/mL for U-8-OHdG and BNP, respectively. Patients with a U-8-OHdG concentration ≥19.1ng/mg·Cr or a BNP concentration ≥209pg/mL had a significantly higher cardiovascular-related death risk, but U-8-OHdG had better predictive value compared with BNP. CONCLUSION: These findings suggested that U-8-OHdG was a powerful predictor of cardiovascular-related death in patients with CS, suggesting that active CS patients with elevated U-8-OHdG levels might be resistant to corticosteroid therapy.


Asunto(s)
Corticoesteroides/uso terapéutico , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/orina , Desoxiguanosina/análogos & derivados , Sarcoidosis/tratamiento farmacológico , Sarcoidosis/orina , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Anciano , Biomarcadores/orina , Cardiomiopatías/mortalidad , Desoxiguanosina/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/orina , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sarcoidosis/mortalidad , Análisis de Supervivencia , Resultado del Tratamiento
5.
Int J Cardiol ; 190: 319-28, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25935620

RESUMEN

BACKGROUND: Inflammation and oxidative stress play a crucial role in the pathogenesis of cardiac sarcoidosis (SAR). We investigated whether urinary (U) 8-hydroxy-2'-deoxyguanosine (8-OHdG)--an oxidative DNA damage marker--was related to SAR inflammatory activity. METHODS: U-8-OHdG levels were measured in 31 SAR patients, classified as active (n=17) or non-active (n=14) based on (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET/CT), 28 dilated cardiomyopathy (DCM) patients, and 30 controls. In active SAR patients, U-8-OHdG levels were reexamined and compared with (18)F-FDG-PET/CT results at 6 months after corticosteroid treatment to assess therapeutic response. RESULTS: Immunohistochemical examination of left ventricle (LV) autopsy samples from SAR patients revealed positive 8-OHdG staining in cardiomyocyte nuclei from LV sections showing (18)F-FDG accumulation on PET/CT, while serum 8-OHdG levels were significantly higher in the coronary sinus than in the aortic root only in active SAR patients. U-8-OHdG levels in SAR patients were higher than those in controls, and significantly higher in active SAR patients than in non-active SAR and DCM patients. U-8-OHdG was a powerful predictor of active SAR in receiver operating characteristic curve analysis (AUC, 0.98; 95% CI, 0.94-1.02; optimal cutoff value, 13.1 ng/mg creatinine), with a sensitivity of 88.2% and a specificity of 92.9%. U-8-OHdG levels in responders significantly decreased at 6 months after corticosteroid treatment initiation, in proportion with the decrease in the focal cardiac uptake of (18)F-FDG. CONCLUSIONS: U-8-OHdG is a potentially clinically useful biomarker for evaluating inflammatory activity and monitoring the effectiveness of corticosteroid therapy in SAR patients.


Asunto(s)
Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/orina , Desoxiguanosina/análogos & derivados , Sarcoidosis/diagnóstico por imagen , Sarcoidosis/orina , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Anciano , Biomarcadores/orina , Estudios de Cohortes , Desoxiguanosina/orina , Femenino , Humanos , Inflamación/diagnóstico por imagen , Inflamación/orina , Masculino , Persona de Mediana Edad , Cintigrafía
6.
PLoS One ; 10(1): e0114314, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25614983

RESUMEN

OBJECTIVES: The purpose of this study was to investigate whether adding a low-dose ß1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism. BACKGROUND: The molecular mechanism underlying how the combination of low-dose ß1-blocker and milrinone affects intracellular Ca(2+) handling in heart failure remains unclear. METHODS: We investigated the effect of milrinone plus landiolol on intracellular Ca(2+) transient (CaT), cell shortening (CS), the frequency of diastolic Ca(2+) sparks (CaSF), and sarcoplasmic reticulum Ca(2+) concentration ({Ca(2+)}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB). RESULTS: In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca(2+)}SR. Co-administration of ß1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca(2+)}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes. CONCLUSION: A low-dose ß1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca(2+) leak.


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/farmacología , Calcio/metabolismo , Cardiotónicos/farmacología , Milrinona/farmacología , Miocitos Cardíacos/metabolismo , Retículo Sarcoplasmático/metabolismo , Animales , Señalización del Calcio , Células Cultivadas , Perros , Miocitos Cardíacos/efectos de los fármacos , Canal Liberador de Calcio Receptor de Rianodina/metabolismo
7.
Biochem Biophys Res Commun ; 448(1): 1-7, 2014 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-24755079

RESUMEN

AIMS: Calmodulin (CaM) plays a key role in modulating channel gating in ryanodine receptor (RyR2). Here, we investigated (a) the pathogenic role of CaM in the channel disorder in CPVT and (b) the possibility of correcting the CPVT-linked channel disorder, using knock-in (KI) mouse model with CPVT-associated RyR2 mutation (R2474S). METHODS AND RESULTS: Transmembrane potentials were recorded in whole cell current mode before and after pacing (1-5 Hz) in isolated ventricular myocytes. CaM binding was assessed by incorporation of exogenous CaM fluorescently labeled with HiLyte Fluor(®) in saponin-permeabilized myocytes. In the presence of cAMP (1 µM) the apparent affinity of CaM binding to the RyR decreased in KI cells (Kd: 140-400 nM), but not in WT cells (Kd: 110-120 nM). Gly-Ser-His-CaM (GSH-CaM that has much higher RyR-binding than CaM) restored normal binding to the RyR of cAMP-treated KI cells (140 nM). Neither delayed afterdepolarization (DAD) nor triggered activity (TA) were observed in WT cells even at 5Hz pacing, whereas both DAD and TA were observed in 20% and 12% of KI cells, respectively. In response to 10nM isoproterenol, only DAD (but not TA) was observed in 11% of WT cells, whereas in KI cells the incidence of DAD and TA further increased to 60% and 38% of cells, respectively. Addition of GSH-CaM (100 nM) to KI cells decreased both DADs and TA (DAD: 38% of cells; TA: 10% of cells), whereas CaM (100 nM) had no appreciable effect. Addition of GSH-CaM to saponin-permeabilized KI cells decreased Ca(2+) spark frequency (+33% of WT cells), which otherwise markedly increased without GSH-CaM (+100% of WT cells), whereas CaM revealed much less effect on the Ca(2+) spark frequency (+76% of WT cells). Then, by incorporating CaM or GSH-CaM to intact cells (with protein delivery kit), we assessed the in situ effect of GSH-CaM (cytosolic [CaM]=~240 nM, cytosolic [GSH-CaM]=~230 nM) on the frequency of spontaneous Ca(2+) transient (sCaT, % of total cells). Addition of 10nM isoproterenol to KI cells increased sCaT after transient 5 Hz pacing (37%), whereas it was much more attenuated by GSH-CaM (9%) than by CaM (26%) (P<0.01 vs CaM). CONCLUSIONS: Several disorders in the RyR channel function characteristic of the CPVT-mutant cells (increased spontaneous Ca(2+) leak, delayed afterdepolarization, triggered activity, Ca(2+) spark frequency, spontaneous Ca(2+) transients) can be corrected to a normal function by increasing the affinity of CaM binding to the RyR.


Asunto(s)
Calmodulina/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Taquicardia Ventricular/tratamiento farmacológico , Potenciales de Acción/efectos de los fármacos , Animales , Técnicas de Sustitución del Gen , Isoproterenol/farmacología , Ratones , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/fisiología , Canal Liberador de Calcio Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Taquicardia Ventricular/fisiopatología
8.
Cardiology ; 127(2): 105-13, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24296610

RESUMEN

OBJECTIVE: Recently, we reported that low-dose landiolol (1.5 µg·kg(-1)·min(-1)), an ultra-short-acting ß-blocker, safely decreased the heart rate (HR) in patients with acute decompensated heart failure (ADHF) and sinus tachycardia, thereby improving cardiac function. We investigated whether low-dose landiolol effectively decreased the HR in ADHF patients with rapid atrial fibrillation (AF). METHODS: We enrolled 23 ADHF patients with rapid AF (HR ≥120 beats·min(-1) and New York Heart Association class III-IV) and systolic heart failure (SHF: n = 12) or diastolic heart failure (DHF: n = 11) who received conventional therapy with diuretics, vasodilators, and/or low-dose inotropes. They were administered continuous intravenous infusion of low-dose landiolol (1.0-2.0 µg·kg(-1)·min(-1)), and their electrocardiograms and blood pressures were monitored for 24 h thereafter. RESULTS: Two hours after starting landiolol, the HR was reduced significantly (22%), without a reduction in blood pressure, and remained constant thereafter. The HR reduction 2 h after landiolol administration was significantly greater in the DHF group than in the SHF group. No incidence of hypotension was recorded. CONCLUSIONS: Digitalis or amiodarone is currently recommended for HR control in ADHF patients with rapid AF. Our results showed that continuous infusion of low-dose landiolol may also be useful as first-line therapy in these patients.


Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Fibrilación Atrial/tratamiento farmacológico , Insuficiencia Cardíaca/tratamiento farmacológico , Frecuencia Cardíaca/efectos de los fármacos , Morfolinas/administración & dosificación , Urea/análogos & derivados , Enfermedad Aguda , Anciano , Fibrilación Atrial/fisiopatología , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Urea/administración & dosificación
9.
J Echocardiogr ; 12(3): 89-97, 2014 09.
Artículo en Inglés | MEDLINE | ID: mdl-27276892

RESUMEN

BACKGROUND: Left ventricular (LV) rotation plays an important role in cardiac function both at rest and during exercise in sinus rhythm. The kinetics of rotation during exercise and the relation between exercise tolerance and rotation-related parameters in patients with atrial fibrillation (AF) are unknown. METHODS: Twenty-nine patients (age 62 ± 13 years, 6 females) with AF and preserved LV ejection fraction (LVEF) were studied using two-dimensional speckle tracking echocardiography at rest and during exercise with a supine bicycle ergometer (20 W, 10 min). We measured the systolic rotation (Rot) and the peak rotation rate in systole and early diastole (eRotR) at the apical and basal levels of the LV. All patients underwent cardiopulmonary exercise testing to obtain their percent achieved of the predicted peak oxygen consumption (% peak VO2) value. RESULTS: During exercise, apical Rot-related indices were significantly increased only in the preserved % peak VO2 group. In contrast, E/e' was significantly elevated only in the reduced % peak VO2 group. Multivariable stepwise regression analysis showed that apical ΔRot was independently associated with % peak VO2 (ß = 0.72; p < 0.01). Apical ΔeRotR, which could not be selected as an independent predictor of % peak VO2, had a good linear correlation with apical ΔRot (r = 0.81, p < 0.01). CONCLUSIONS: The augmentation of apical rotation in response to exercise may coincide with an increase of the apical derotation rate, and apical rotation reserve may reflect exercise tolerance in patients with AF and preserved LVEF.


Asunto(s)
Fibrilación Atrial/fisiopatología , Ecocardiografía , Tolerancia al Ejercicio , Función Ventricular Izquierda , Anciano , Prueba de Esfuerzo , Femenino , Humanos , Cinética , Masculino , Persona de Mediana Edad , Rotación , Volumen Sistólico
10.
BMC Anesthesiol ; 13: 14, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23837943

RESUMEN

BACKGROUND: Currently, in the field of general anesthesia, balanced anesthesia in combination with analgesic, hypnotic, and muscle relaxant is commonly used. Remifentanil is the standard analgesic used in balanced anesthesia, and has contributed greatly to reduce the physical stress of the patient during surgery. We compared the stress response suppression effect of remifentanil by measuring stress hormones in 2 groups treated with different analgesic doses in orthopedic surgery using a tourniquet. METHODS: Twenty patients were randomly divided into 2 groups (10 patients each) undergoing maintenance of general anesthesia with 0.25 µg/kg/min remifentanil and sevoflurane (Group A) and 1.0 µg/kg/min remifentanil and sevoflurane (Group B). Hemodynamic changes, adrenocorticotropic hormone (ACTH), cortisol, antidiuretic hormone (ADH), adrenaline (Ad), noradrenaline (NAd), dopamine (DOA), insulin, and blood glucose were measured at the initiation of general anesthesia,10 minutes after the initiation of tourniquet application, and immediately before and 10 minutes after the completion of tourniquet application. RESULTS: ACTH, CORTISOL, ADH, AD, AND NAD LEVELS IN GROUP B WERE SIGNIFICANTLY LOWER (ACTH AND CORTISOL: P < 0.01, ADH, Ad, and NAd: P < 0.05) than those in Group A. No significant differences were noted in DOA, insulin, or blood glucose levels between the groups. CONCLUSION: Anesthesia management with high-dose remifentanil (1.0 µg/kg/min) suppressed intraoperative tourniquet pain-induced stress hormone release, suggesting its usefulness in stabilizing hemodynamics. TRIAL REGISTRATION: JMA-IIA00094.

11.
Cardiovasc Res ; 96(3): 433-43, 2012 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22893680

RESUMEN

AIMS: The channel function of the cardiac ryanodine receptor (RyR2) is modulated by calmodulin (CaM). However, the involvement of CaM in aberrant Ca(2+) release in diseased hearts remains unclear. Here, we investigated the pathogenic role of defective CaM binding to the RyR2 in the channel dysfunction associated with heart failure. METHODS AND RESULTS: The involvement of CaM in aberrant Ca(2+) release was assessed in normal and pacing-induced failing canine hearts. The apparent affinity of CaM for RyR2 was considerably lower in failing sarcoplasmic reticulum (SR) compared with normal SR. Thus, the amount of CaM bound to RyR2 was markedly decreased in failing myocytes. Expression of the CaM isoform Gly-Ser-His-CaM (GSH-CaM), which has much higher binding affinity than wild-type CaM for RyR1, restored normal CaM binding to RyR2 in both SR and myocytes of failing hearts. The Ca(2+) spark frequency (SpF) was markedly higher and the SR Ca(2+) content was lower in failing myocytes compared with normal myocytes. The incorporation of GSH-CaM into the failing myocytes corrected the aberrant SpF and SR Ca(2+) content to normal levels. CONCLUSION: Reduced CaM binding to RyR2 seems to play a critical role in the pathogenesis of aberrant Ca(2+) release in failing hearts. Correction of the reduced CaM binding to RyR2 stabilizes the RyR2 channel function and thereby restores normal Ca(2+) handling and contractile function to failing hearts.


Asunto(s)
Calmodulina/metabolismo , Insuficiencia Cardíaca/metabolismo , Contracción Miocárdica , Miocitos Cardíacos/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Animales , Señalización del Calcio , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Estimulación Cardíaca Artificial , Modelos Animales de Enfermedad , Perros , Activación Enzimática , Insuficiencia Cardíaca/fisiopatología , Retículo Sarcoplasmático/metabolismo , Factores de Tiempo
12.
Circ J ; 76(7): 1646-53, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22481100

RESUMEN

BACKGROUND: The purpose of this study was to determine whether a low-dose ß-blocker, in combination with milrinone, improves cardiac function in acute decompensated heart failure (ADHF) with tachycardia. METHODS AND RESULTS: Twenty ADHF patients (New York Heart Association classification III, n=1, and IV, n=19; heart rate [HR], 107±12 beats/min; left ventricular ejection fraction, 24±7%; cardiac index [CI], 2.2±0.6 L·min(-1)·m(-2); pulmonary capillary wedge pressure [PCWP], 26±8 mmHg) were enrolled in this study. The patients first underwent conventional therapy with milrinone, vasodilators and diuretics; landiolol (1.5-6.0 µg·kg(-1)·min(-1); i.v.), which is an ultra-short-acting ß(1)-selective blocker, was then added to the treatment regimen to study its effect on hemodynamics. Low-dose landiolol (1.5 µg·kg(-1)·min(-1)) significantly reduced HR by 11% without changing blood pressure (BP) and CI, whereas higher doses (≥3.0 µg·kg(-1)·min(-1)) tended to decrease BP and CI while increasing PCWP and systemic vascular resistance. After treatment with landiolol (1.5 µg·kg(-1)·min(-1)), hemodynamic parameters such as PCWP, stroke volume index, SvO(2), rate pressure product, filling time/RR, E/e', and Tei index were significantly improved. CONCLUSIONS: A low-dose ß-blocker in combination with milrinone improved cardiac function in ADHF patients with tachycardia; therefore, it may be considered as an adjunct therapy for use when standard therapy with milrinone is not effective at slowing HR.


Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Arritmias Cardíacas/tratamiento farmacológico , Cardiotónicos/administración & dosificación , Insuficiencia Cardíaca/tratamiento farmacológico , Hemodinámica/efectos de los fármacos , Milrinona/administración & dosificación , Morfolinas/administración & dosificación , Urea/análogos & derivados , Disfunción Ventricular Izquierda/tratamiento farmacológico , Función Ventricular Izquierda/efectos de los fármacos , Enfermedad Aguda , Adulto , Anciano , Arritmias Cardíacas/etiología , Arritmias Cardíacas/fisiopatología , Distribución de Chi-Cuadrado , Quimioterapia Combinada , Femenino , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Japón , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Presión Esfenoidal Pulmonar/efectos de los fármacos , Recuperación de la Función , Volumen Sistólico , Factores de Tiempo , Resultado del Tratamiento , Urea/administración & dosificación , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/fisiopatología
13.
Circ J ; 76(1): 117-26, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22008315

RESUMEN

BACKGROUND: The authors recently reported that urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) derived from cardiac tissue reflects clinical status and cardiac dysfunction severity in patients with chronic heart failure (CHF). The aim of the present study was to investigate whether U8-OHdG levels can accurately predict cardiac events in CHF patients and their response to ß-blocker treatment. METHODS AND RESULTS: Plasma brain natriuretic peptide (BNP) and U8-OHdG levels were measured in 186 consecutive CHF patients before discharge. Patients were then prospectively followed (median follow-up, 649 days) with endpoints of cardiac death or hospitalization due to progressive heart failure. From receiver operating characteristic curve analysis, cut-offs were 12.4ng/mg creatinine (Cr) for U8-OHdG and 207pg/ml for BNP. On multivariate Cox analysis, U8-OHdG and BNP were independent predictors of cardiac events. Patients were classified into 4 groups according to U8-OHdG and BNP cut-offs. The hazard ratio for cardiac events in patients with BNP ≥207pg/ml and U8-OHdG ≥12.4ng/mg Cr was 16.2 compared with approximately 4 for patients with only 1 indicator above its respective cut-off. Furthermore, carvedilol therapy was initiated in 30 CHF patients. In responders (≥10% increase in left ventricular ejection fraction [LVEF] or ≥1 class decrease in New York Heart Association [NYHA] class), U8-OHdG levels decreased significantly along with improved NYHA class, LVEF, and BNP levels after treatment. CONCLUSIONS: U8-OHdG may be a useful biomarker for predicting cardiac events and evaluating ß-blocker therapy effectiveness in CHF patients.


Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Carbazoles/uso terapéutico , Muerte Súbita Cardíaca/epidemiología , Desoxiguanosina/análogos & derivados , Insuficiencia Cardíaca Sistólica/tratamiento farmacológico , Insuficiencia Cardíaca Sistólica/mortalidad , Propanolaminas/uso terapéutico , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Anciano , Biomarcadores/sangre , Biomarcadores/orina , Carvedilol , Enfermedad Crónica , Desoxiguanosina/orina , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca Sistólica/orina , Humanos , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/sangre , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , Resultado del Tratamiento
14.
J Med Ultrason (2001) ; 38(3): 157-9, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27278503

RESUMEN

A 35-year-old woman was admitted for progressive dyspnea with lower limb edema. Transthoracic echocardiography showed severe left ventricular hypertrophy (LVH) and heart failure with preserved ejection fraction (HFPEF). Electron microscopy of an endomyocardial biopsy sample revealed a high density of mitochondria of abnormal size and shape. We report a case of mitochondrial disease with severe LVH and HFPEF.

15.
Masui ; 59(9): 1185-9, 2010 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-20857679

RESUMEN

BACKGROUND: Transversus abdominis plane block (TAP block) is useful for lower abdominal operations. Recently, ultrasound guided nerve block has been performed with ultrasound scanning. METHODS: We investigated the effectiveness of TAP block in 64 pediatric patients (aged 5-12 years, F/M = 21/43) receiving bone graft from the ilium to the alveolar cleft. We compared the dosages for postoperative analgesics between the groups of TAP block and non-TAP block. RESULTS: In the TAP block group, the frequency of using the postoperative analgesics was lower compared with non TAP block group (P < 0.05). CONCLUSIONS: We concluded that TAP block was effective in pediatric patients receiving bone graft to the alveolar cleft.


Asunto(s)
Proceso Alveolar/anomalías , Trasplante Óseo , Bloqueo Nervioso/métodos , Músculos Abdominales/inervación , Proceso Alveolar/cirugía , Alveoloplastia , Preescolar , Femenino , Humanos , Masculino , Estudios Retrospectivos
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