RESUMEN
Wnt/ß-catenin signalling controls adult heart remodelling in part via regulation of cardiac progenitor cell (CPC) differentiation. An enhanced understanding of mechanisms controlling CPC biology might facilitate the development of new therapeutic strategies in heart failure. We identified and characterized a novel cardiac interaction between Krueppel-like factor 15 and components of the Wnt/ß-catenin pathway leading to inhibition of transcription. In vitro mutation, reporter assays and co-localization analyses revealed that KLF15 requires both the C-terminus, necessary for nuclear localization, and a minimal N-terminal regulatory region to inhibit transcription. In line with this, functional Klf15 knock-out mice exhibited cardiac ß-catenin transcriptional activation along with functional cardiac deterioration in normal homeostasis and upon hypertrophy. We further provide in vivo and in vitro evidences for preferential endothelial lineage differentiation of CPCs upon KLF15 deletion. Via inhibition of ß-catenin transcription, KLF15 controls CPC homeostasis in the adult heart similar to embryonic cardiogenesis. This knowledge may provide a tool for reactivation of this apparently dormant CPC population in the adult heart and thus be an attractive approach to enhance endogenous cardiac repair.
Asunto(s)
Diferenciación Celular , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica , Corazón/fisiología , Células Madre/fisiología , Factores de Transcripción/metabolismo , Proteínas Wnt/biosíntesis , beta Catenina/biosíntesis , Animales , Regulación hacia Abajo , Factores de Transcripción de Tipo Kruppel , Ratones , Ratones Noqueados , Transcripción Genética , Proteínas Wnt/antagonistas & inhibidores , Vía de Señalización Wnt , beta Catenina/antagonistas & inhibidoresRESUMEN
AIMS: Mortality in chronic heart failure (CHF) patients with left bundle branch block (LBBB) is high. Cardiac resynchronization therapy (CRT) reduces symptoms and mortality in CHF patients with LBBB. Whether CRT promotes or prevents ventricular tachycardia (VT)/ventricular fibrillation (VF) remains controversial, however. Therefore, we aimed to analyse arrhythmia-related CRT effects and characterized the VT/VF incidence in CRT-defibrillator patients and matched controls with conventional implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden cardiac death. METHODS AND RESULTS: We enrolled 134 patients [110 men, left ventricular ejection fraction (LVEF) 24 ± 8%, 71 coronary artery disease, CRT-ICD 67, conventional ICD matched controls 67, follow-up 31 ± 17 months] and monitored overall survival and the time to a first VT/VF episode. Controls did not have LBBB. They were otherwise matched for age, LVEF, and follow-up duration. Gender and underlying disease did not differ between the groups. Kaplan-Meier analysis revealed more favourable arrhythmia-free survival in CRT-ICD vs. conventional ICD patients [hazard ratio (HR) 2.26, confidence interval (CI) 1.09-4.67, log rank P = 0.023]. The difference persisted in the multivariate Cox regression analysis (HR 3.25, CI 1.18-8.93, P= 0.022). Overall survival was similar in both groups (HR 1.45, CI 0.55-3.82, P = 0.45). CONCLUSIONS: Chronic heart failure patients with LBBB treated with CRT-ICD, experience less and delayed VT/VF episodes compared with matched controls without LBBB receiving conventional ICD. In the long-term, CRT appears to exert antiarrhythmic effects and to attenuate the particularly high arrhythmia-related risk of CHF patients with LBBB. The incremental benefit of adding the ICD option to CRT pacing in LBBB patients appears questionable.
Asunto(s)
Bloqueo de Rama/prevención & control , Terapia de Resincronización Cardíaca/estadística & datos numéricos , Desfibriladores Implantables/estadística & datos numéricos , Taquicardia Ventricular/prevención & control , Fibrilación Ventricular/prevención & control , Bloqueo de Rama/mortalidad , Estudios de Casos y Controles , Terapia Combinada/estadística & datos numéricos , Comorbilidad , Supervivencia sin Enfermedad , Femenino , Alemania/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Prevalencia , Medición de Riesgo , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Taquicardia Ventricular/mortalidad , Fibrilación Ventricular/mortalidadRESUMEN
BACKGROUND: The combination of intravenous propofol and midazolam is frequently used to provide unconscious sedation during catheter ablation of atrial fibrillation (AF), but only a very few reports are available on the influence of prolonged propofol infusion on arterial blood gas, blood pressure, and anesthesia-associated complications during ablation of AF. The purpose of this study was to assess tolerance and safety of unconscious sedation with intravenous propofol and midazolam during catheter ablation of AF. METHODS: A total of 316 consecutive patients (age 59 ± 10 years, 68% men) presenting to our center for catheter ablation of symptomatic AF were enrolled prospectively. A total number of 424 procedures were performed under unconscious sedation with propofol and midazolam. SaO(2), electrocardiogram, arterial blood pressure, and arterial blood gases were monitored throughout the procedure. RESULTS: Mean procedure duration was 235 ± 48 minutes. Patients received 1.125 ± 684 mg propofol, 9.5 ± 3 midazolam, and 1.963 ± 813 mL NaCl infusion. Complications during the procedure were identified in eight patients (2.5%, one × coronary air embolization, one × myocardial infarction, four × pericardial effusion, two × pericardial tamponade). All eight patients were symptomatic (distress, report of pain); none of the complications was attributable to unconscious sedation itself. CONCLUSION: Unconscious sedation with propofol and midazolam in AF ablation procedures lasting 3-5 hours did not result in severe changes of vital parameters or serum electrolytes. Anesthesia-associated problems were not observed. Propofol and midazolam can be safely used during catheter ablation of AF.
Asunto(s)
Fibrilación Atrial/epidemiología , Fibrilación Atrial/cirugía , Ablación por Catéter/estadística & datos numéricos , Sedación Profunda/estadística & datos numéricos , Midazolam , Propofol , Combinación de Medicamentos , Femenino , Alemania/epidemiología , Humanos , Hipnóticos y Sedantes , Masculino , Persona de Mediana Edad , Medición de Riesgo , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: Guideline-recommended beta-blocker (BB) target doses for patients with chronic heart failure can often not be reached. This secondary analysis of the CIBIS-ELD trial was carried out to better understand reasons for not achieving target doses. METHODS: Changes in heart rate (HR) and other parameters during a 12-week up-titration period in 302 BB naïve patients were evaluated in the subgroups achieving 12.5, 25, 50, and 100% of the target dose (groups 1, 2, 3, and 4, respectively). RESULTS: Achieved doses predominantly depended on baseline HR (means 68, 74, 76, and 84 bpm in groups 1-4, respectively, P<0.001). HR was consistently reduced with each dose level to 65, 63, and 62 bpm in groups 1-3 and to 71 bpm in group 4 (P<0.001). When adjusted for baseline, HR reduction achieved in group 3 was better than in group 4 (difference -5.4 bpm, P<0.05). More patients in groups 3/4 than in groups 1/2 improved in NYHA class (P = 0.01). NTproBNP increased by 38% in group 4 (P<0.01) but not in the others (P<0.05 between groups). Changes in blood pressure, six-minute walk distance and self-rated health were comparable in all groups. CONCLUSIONS: The desired effect of HR reduction appears to be a predominant limitation for BB up-titration. Vice versa, achieving the target dose may be a sign of insufficient response rather than successful treatment. In view of these results and the well-known importance of HR for survival, not target doses, but HR control should be given priority in BB treatment for heart failure.
Asunto(s)
Antagonistas Adrenérgicos beta/administración & dosificación , Antagonistas Adrenérgicos beta/sangre , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Bisoprolol/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Carbazoles/administración & dosificación , Carvedilol , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Sistemas de Liberación de Medicamentos/métodos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Propanolaminas/administración & dosificación , Resultado del TratamientoRESUMEN
OBJECTIVES: We hypothesized that infarct transmurality assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) predicts arrhythmic events in patients with chronic myocardial infarction. BACKGROUND: Patients with decreased left ventricular function due to chronic myocardial infarction are at increased risk for life-threatening arrhythmias related to infarcted tissue. LGE-CMR accurately detects infarct morphology. METHODS: We prospectively enrolled 52 patients with chronic myocardial infarction referred for primary preventive implantable cardioverter-defibrillator (ICD) implantation following MADIT (Multicenter Automatic Defibrillator Implantation Trial) study criteria. Using LGE-CMR, left ventricular volumes, function, and infarct morphology were assessed including calculation of total and relative infarct mass, infarct border, infarct border zone, and infarct transmurality. RESULTS: Patients were followed for 1,235 ± 341 days. The primary combined endpoint including appropriate device therapy (ICD discharge or antitachycardia pacing) or death from cardiac cause occurred in 16 individuals resulting in an annual event rate of 4.7%. Six patients received an appropriate shock, 7 patients received recurrent appropriate antitachycardia pacing for sustained ventricular tachycardia, and 3 patients died of cardiac cause. There was a significant association to relative infarct mass (38 ± 8% vs. 28 ± 14%, p = 0.02), infarct transmurality (24 ± 8 g vs. 16 ± 12 g, p = 0.02), and relative infarct transmurality (RIT) (63 ± 12% vs. 48 ± 23%, p = 0.01). In separate logistic regression models, no variable emerged as significant when combined with RIT. As a single effect, RIT emerged as a predictor of the primary endpoint (p = 0.02). A RIT cutoff at 43% resulted in a sensitivity of 88%, a specificity of 50%, a positive predictive value of 44%, and a negative predictive value of 90%. CONCLUSIONS: In patients with chronic myocardial infarction scheduled for primary preventive ICD implantation, infarct transmurality as defined by LGE-CMR identifies a subgroup with increased risk for life-threatening arrhythmias and cardiac death.
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Arritmias Cardíacas/etiología , Medios de Contraste , Gadolinio DTPA , Imagen por Resonancia Cinemagnética , Infarto del Miocardio/diagnóstico , Miocardio/patología , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/mortalidad , Arritmias Cardíacas/patología , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/prevención & control , Desfibriladores Implantables , Supervivencia sin Enfermedad , Cardioversión Eléctrica/instrumentación , Alemania , Humanos , Estimación de Kaplan-Meier , Modelos Logísticos , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/mortalidad , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/terapia , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Volumen Sistólico , Factores de Tiempo , Resultado del Tratamiento , Función Ventricular IzquierdaRESUMEN
OBJECTIVE: We hypothesized that in patients with heart failure with normal left ventricular (LV) ejection fraction (HFNEF), the same fibrotic processes that affect the subendocardial layer of the LV could also alter the subendocardial fibers of the right ventricle (RV). Consequently, these alterations and to a lesser extent chronically elevated pulmonary arterial pressures would lead to both systolic and diastolic subendocardial dysfunction of the RV (i.e., impaired RV longitudinal systolic and diastolic function) in patients with HFNEF. METHODS: Patients with HFNEF and a control group consisting of asymptomatic patients with LV diastolic dysfunction (asymptomatic LVDD) matched by age, gender, and LV ejection fraction were studied by two-dimensional speckle-tracking echocardiography. RESULTS: A total of 565 patients were included (201 with HFNEF and 364 with asymptomatic LVDD). RV longitudinal diastolic (RV global longitudinal early-diastolic strain rate [RV-SRe]) and systolic (RV global longitudinal systolic strain [RV-Strain]) function were significantly more impaired in patients with HFNEF than in patients with asymptomatic LVDD (HFNEF: RV-Strain -14.41% ± 3.80% and RV-SRe 0.86 ± 0.33 s(-1); asymptomatic LVDD: RV-Strain -16.90% ± 4.28% and RV-SRe 1.02 ± 0.34 s(-1); all P < .0001). On multiple regression analysis, LV global longitudinal systolic strain was the most important independent predictor of RV longitudinal systolic and diastolic function, in contrast with pulmonary arterial systolic pressure, which was weakly related to these functions. Furthermore, in patients with HFNEF the subendocardial function of both the LV and RV were significantly impaired in similar proportions. In that regard, in patients with HFNEF the prevalences of RV longitudinal systolic and diastolic dysfunction were 75% and 48%, whereas the rates of LV longitudinal systolic and diastolic dysfunction were 80% and 60%, respectively. In addition, patients with both systolic and diastolic longitudinal dysfunction of the RV presented worse New York Heart Association functional class. CONCLUSION: In patients with HFNEF, RV subendocardial systolic and diastolic dysfunction are common and possibly associated with the same fibrotic processes that affect the subendocardial layer of the LV and to a lesser extent with RV pressure overload. Furthermore, our findings suggest that RV longitudinal systolic and diastolic dysfunction could contribute to the symptomatology of patients with HFNEF.
Asunto(s)
Diástole , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Volumen Sistólico , Sístole , Disfunción Ventricular Derecha/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Algoritmos , Estudios de Casos y Controles , Ecocardiografía , Femenino , Insuficiencia Cardíaca/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores de Riesgo , Disfunción Ventricular Derecha/fisiopatologíaRESUMEN
AIMS: Low-dose epoetin-ß improved neo-angiogenesis and cardiac regeneration in experimental models of ischaemic cardiomyopathy without raising haemoglobin. No clinical study has tested this approach to date. METHODS AND RESULTS: We performed a randomized, placebo-controlled, double-blind, single-centre study of 35 IU/kg body weight epoetin-ß given subcutaneously once weekly for 6 months started within 3 weeks after successful percutaneous coronary intervention (PCI). Patients were included if they presented with a lesion within the proximal segment of the left anterior descending artery, the right coronary artery, or circumflex and had symptomatic heart failure. Patients with ST-segment elevation due to an acute myocardial infarct were excluded. The outcome variables were measured at baseline and at 6 months. Primary outcome measure was individual change in ejection fraction; secondary outcome was safety, change in N-terminal pro-brain natriuretic peptide, and peak VO(2). Twenty-four patients completed the 6-month treatment course. No adverse event related to the treatment occurred. Low-dose epoetin-ß following PCI significantly improved global ejection fraction as measured by echocardiography (EPO: ΔEF 5.2 ± 2.0%, P= 0.013; placebo: ΔEF 0.3 ± 1.6%, P= 0.851; P= 0.019 for the inter-group difference) and cardiac magnetic resonance (EPO: ΔEF 3.1 ± 1.6%, P= 0.124; placebo: -1.9 ± 1.2%, P= 0.167; P= 0.042 for the inter-group difference). N-terminal pro-brain natriuretic peptide levels decreased in both groups without significant inter-group differences. Peak VO(2) levels increased significantly by 3.9 ± 1.1% (P< 0.05) in the EPO group, whereas in the placebo group the increase did not reach statistical significance (Δpeak VO(2) 3.0 ± 1.6, P = ns). No significant difference regarding peak VO(2) was observed between the EPO and placebo groups. CONCLUSIONS: Low-dose epoetin-ß treatment following PCI is safe and feasible, and has possible beneficial effects on global ejection fraction and measures of exercise capacity. Extended low-dose epoetin-ß treatment warrants further mechanistic studies as well as larger clinical trials. CLINICAL TRIAL REGISTRATION INFORMATION: NCT00568542.
Asunto(s)
Eritropoyetina/administración & dosificación , Insuficiencia Cardíaca/tratamiento farmacológico , Algoritmos , Angioplastia Coronaria con Balón , Método Doble Ciego , Eritropoyetina/sangre , Tolerancia al Ejercicio , Femenino , Insuficiencia Cardíaca/complicaciones , Hemoglobinas/análisis , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Consumo de Oxígeno , Proyectos Piloto , Proteínas Recombinantes , Volumen Sistólico , Función Ventricular IzquierdaRESUMEN
BACKGROUND: The authors hypothesized that in patients with heart failure with normal left ventricular (LV) ejection fraction (HFNEF), the same fibrotic processes that affect the subendocardial layer of the left ventricle could also alter the subendocardial fibers of the left atrium. Consequently, these fibrotic alterations, together with chronically elevated LV filling pressures, would lead to both systolic and diastolic subendocardial dysfunction of the left atrium (i.e., impaired left atrial [LA] longitudinal systolic and diastolic function) in patients with HFNEF. METHODS: Patients with HFNEF and a control group consisting of asymptomatic patients with LV diastolic dysfunction (LVDD) matched by age, gender, and LV ejection fraction were studied using two-dimensional speckle-tracking echocardiography. RESULTS: A total of 420 patients were included (119 with HFNEF and 301 with asymptomatic LVDD). LA longitudinal systolic (LA late diastolic strain rate) and diastolic (LA systolic strain and strain rate) function was significantly more impaired in patients with HFNEF (LA late diastolic strain rate, -1.17 ± 0.63 s(-1); LA systolic strain, 19.9 ± 7.3%; LA systolic strain rate, 1.17 ± 0.46 s(-1)) compared with those with asymptomatic LVDD (-1.80 ± 0.70 s(-1), 30.8 ± 11.4%, and 1.67 ± 0.59 s(-1), respectively) (all P values < .0001). On multiple regression analysis, LV global longitudinal systolic strain and diastolic strain rate were the most important independent predictors of LA longitudinal systolic and diastolic function, in contrast to noninvasive LV filling pressures (i.e., mitral E/e' average septal-lateral ratio), which were modestly related to LA longitudinal systolic and diastolic function. Furthermore, in patients with HFNEF, the subendocardial function of both the left atrium and the left ventricle was significantly impaired in high proportions. In that regard, in patients with HFNEF, the rate of LA longitudinal systolic and diastolic dysfunction was 65.5% and 28.5%, whereas the prevalence of LV longitudinal systolic and diastolic dysfunction was 81.5% and 58%, respectively. In addition, patients with both systolic and diastolic longitudinal dysfunction of the left atrium presented worse NYHA functional class as compared with those with normal LA longitudinal function. CONCLUSIONS: In patients with HFNEF, LA subendocardial systolic and diastolic dysfunction is common and possibly associated with the same fibrotic processes that affect the subendocardial fibers of the left ventricle and to a lesser extent with elevated LV filling pressures. Furthermore, these findings suggest that LA longitudinal systolic and diastolic dysfunction could be related to reduced functional capacity during effort in patients with HFNEF.
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Función del Atrio Izquierdo , Ecocardiografía/métodos , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Anciano , Distribución de Chi-Cuadrado , Diástole , Femenino , Humanos , Masculino , Estadísticas no Paramétricas , Volumen Sistólico , SístoleRESUMEN
AIMS: Various beta-blockers with distinct pharmacological profiles are approved in heart failure, yet they remain underused and underdosed. Although potentially of major public health importance, whether one agent is superior in terms of tolerability and optimal dosing has not been investigated. The aim of this study was therefore to compare the tolerability and clinical effects of two proven beta-blockers in elderly patients with heart failure. METHODS AND RESULTS: We performed a double-blind superiority trial of bisoprolol vs. carvedilol in 883 elderly heart failure patients with reduced or preserved left ventricular ejection fraction in 41 European centres. The primary endpoint was tolerability, defined as reaching and maintaining guideline-recommended target doses after 12 weeks treatment. Adverse events and clinical parameters of patient status were secondary endpoints. None of the beta-blockers was superior with regards to tolerability: 24% [95% confidence interval (CI) 20-28] of patients in the bisoprolol arm and 25% (95% CI 21-29) of patients in the carvedilol arm achieved the primary endpoint (P= 0.64). The use of bisoprolol resulted in greater reduction of heart rate (adjusted mean difference 2.1 b.p.m., 95% CI 0.5-3.6, P= 0.008) and more, dose-limiting, bradycardic adverse events (16 vs. 11%; P= 0.02). The use of carvedilol led to a reduction of forced expiratory volume (adjusted mean difference 50 mL, 95% CI 4-95, P= 0.03) and more, non-dose-limiting, pulmonary adverse events (10 vs. 4%; P < 0.001). CONCLUSION: Overall tolerability to target doses was comparable. The pattern of intolerance, however, was different: bradycardia occurred more often in the bisoprolol group, whereas pulmonary adverse events occurred more often in the carvedilol group. This study is registered with controlled-trials.com, number ISRCTN34827306.
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Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Bisoprolol/uso terapéutico , Carbazoles/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Propanolaminas/uso terapéutico , Antagonistas Adrenérgicos beta/efectos adversos , Bisoprolol/efectos adversos , Carbazoles/efectos adversos , Carvedilol , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Europa (Continente) , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Propanolaminas/efectos adversos , Resultado del TratamientoRESUMEN
Evidence-based treatment for heart failure (HF) comprises beta-blockers, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone receptor antagonists (ARA). Diuretics (DR) are prescribed in acute and chronic HF, but their impact on survival and ventricular tachyarrhythmias (VT/VF) is unclear. The present observational study aims to examine the influence of DR and ARA on survival and appropriate cardioverter/defibrillator (ICD) treatment episodes in routine ICD patients. In 352 consecutive ICD patients (291 men, 60 ± 12 years, LVEF 34 ± 15%, follow-up 37 ± 19 months) overall survival and the time to a first appropriate VT/VF episode were assessed. Electrograms were validated. Potassium and creatinine serum levels and the medical treatment regimen for heart failure were documented at baseline. Multivariate Cox regression analyses revealed significantly worse survival for patients with DR compared to those without DR (OR 0.24, CI 0.08-0.76, P= 0.016), whereas the group with ARA had better survival compared to patients without (OR 2.05, CI 1.02-4.10, P= 0.04). Patient groups did not differ regarding survival without incident VT/VF (DR+ vs. DR- OR 1.10, CI 0.67-1.83, P= 0.70; OR 0.66, CI 0.40-1.09, P= 0.10). Long-term survival appears to be compromised in ICD patients receiving concomitant DR, but is favorably influenced by ARA, although VT/VF incidence does not differ. Randomized analyses are warranted to assess long-term prognostic effects of DR in HF.
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Desfibriladores Implantables , Diuréticos/uso terapéutico , Insuficiencia Cardíaca/mortalidad , Antagonistas de Receptores de Mineralocorticoides/uso terapéutico , Taquicardia Ventricular/epidemiología , Fibrilación Ventricular/epidemiología , Adulto , Anciano , Enfermedad Crónica , Creatinina/sangre , Femenino , Insuficiencia Cardíaca/terapia , Humanos , Incidencia , Masculino , Persona de Mediana EdadAsunto(s)
Depresores del Sistema Nervioso Central/envenenamiento , Etanol/envenenamiento , Miocardio/patología , Adulto , Consumo de Bebidas Alcohólicas , Biomarcadores/sangre , Femenino , Humanos , Inflamación/inducido químicamente , Imagen por Resonancia Magnética , Masculino , Función Ventricular Izquierda/efectos de los fármacos , Adulto JovenRESUMEN
BACKGROUND: In magnetic resonance (MR) imaging, T1, T2 and T2* relaxation times represent characteristic tissue properties that can be quantified with the help of specific imaging strategies. While there are basic software tools for specific pulse sequences, until now there is no universal software program available to automate pixel-wise mapping of relaxation times from various types of images or MR systems. Such a software program would allow researchers to test and compare new imaging strategies and thus would significantly facilitate research in the area of quantitative tissue characterization. RESULTS: After defining requirements for a universal MR mapping tool, a software program named MRmap was created using a high-level graphics language. Additional features include a manual registration tool for source images with motion artifacts and a tabular DICOM viewer to examine pulse sequence parameters. MRmap was successfully tested on three different computer platforms with image data from three different MR system manufacturers and five different sorts of pulse sequences: multi-image inversion recovery T1; Look-Locker/TOMROP T1; modified Look-Locker (MOLLI) T1; single-echo T2/T2*; and multi-echo T2/T2*. Computing times varied between 2 and 113 seconds. Estimates of relaxation times compared favorably to those obtained from non-automated curve fitting. Completed maps were exported in DICOM format and could be read in standard software packages used for analysis of clinical and research MR data. CONCLUSIONS: MRmap is a flexible cross-platform research tool that enables accurate mapping of relaxation times from various pulse sequences. The software allows researchers to optimize quantitative MR strategies in a manufacturer-independent fashion. The program and its source code were made available as open-source software on the internet.
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Algoritmos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Programas Informáticos , Humanos , Lenguajes de Programación , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Familial recurrence of atrial fibrillation (AF) is reported in up to 15% of patients with lone AF. Recently, it was proposed that congenital defects in the morphogenesis of the pulmonary vein myocardium are involved in genetic pathogenesis of lone AF. GATA4 is a cardiac transcription factor essentially involved in myocardial development. Mutations in GATA4 are associated with congenital cardiac malformations. To investigate whether GATA4 mutations represent a genetic origin for AF the coding region of GATA4 was sequenced in 96 patients with lone AF. We found a GATA4 mutation (M247T) in a patient with familial lone AF and atrial septal aneurysm without interatrial shunts. The mutation affects a deeply conserved domain adjacent to the first zinc finger domain of GATA4 and was not reported before. A second GATA4 mutation (A411V) was found in a female patient with sporadic lone AF. This variant was previously reported in patients with cardiac septal defects. However, no anomalies of the atrial or ventricular septa were noted in the AF patient harboring A411V. We report for the first time that mutations in the cardiac transcription factor GATA4 may represent a genetic origin of lone AF. The study proposes that lone AF may share a common genetic origin with congenital cardiac malformations.
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Fibrilación Atrial/genética , Factor de Transcripción GATA4/genética , Defectos de los Tabiques Cardíacos/genética , Mutación/genética , Adulto , Anciano , Secuencia de Aminoácidos , Fibrilación Atrial/patología , Femenino , Defectos de los Tabiques Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Linaje , Homología de Secuencia de AminoácidoRESUMEN
BACKGROUND: Agonistic autoantibodies to the alpha(1)-adrenergic receptor occur in nearly half of patients with refractory hypertension; however, their relevance is uncertain. METHODS/PRINCIPAL FINDINGS: We immunized Lewis rats with the second extracellular-loop peptides of the human alpha(1A)-adrenergic receptor and maintained them for one year. Alpha(1A)-adrenergic antibodies (alpha(1A)-AR-AB) were monitored with a neonatal cardiomyocyte contraction assay by ELISA, and by ERK1/2 phosphorylation in human alpha(1A)-adrenergic receptor transfected Chinese hamster ovary cells. The rats were followed with radiotelemetric blood pressure measurements and echocardiography. At 12 months, the left ventricles of immunized rats had greater wall thickness than control rats. The fractional shortening and dp/dt(max) demonstrated preserved systolic function. A decreased E/A ratio in immunized rats indicated a diastolic dysfunction. Invasive hemodynamics revealed increased left ventricular end-diastolic pressures and decreased dp/dt(min). Mean diameter of cardiomyocytes showed hypertrophy in immunized rats. Long-term blood pressure values and heart rates were not different. Genes encoding sarcomeric proteins, collagens, extracellular matrix proteins, calcium regulating proteins, and proteins of energy metabolism in immunized rat hearts were upregulated, compared to controls. Furthermore, fibrosis was present in immunized hearts, but not in control hearts. A subset of immunized and control rats was infused with angiotensin (Ang) II. The stressor raised blood pressure to a greater degree and led to more cardiac fibrosis in immunized, than in control rats. CONCLUSIONS/SIGNIFICANCE: We show that alpha(1A)-AR-AB cause diastolic dysfunction independent of hypertension, and can increase the sensitivity to Ang II. We suggest that alpha(1A)-AR-AB could contribute to cardiovascular endorgan damage.
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Autoinmunidad/inmunología , Corazón/fisiopatología , Miocardio/patología , Receptores Adrenérgicos alfa 1/inmunología , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Autoanticuerpos/inmunología , Autoanticuerpos/farmacología , Presión Sanguínea , Células CHO , Cricetinae , Cricetulus , Diástole , Electrocardiografía , Ensayo de Inmunoadsorción Enzimática , Perfilación de la Expresión Génica , Humanos , Inmunoglobulina G/inmunología , Masculino , Datos de Secuencia Molecular , Miocardio/inmunología , Miocardio/metabolismo , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/fisiología , Ratas , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Accumulating evidence indicates that Visinin-like protein-1 (VILIP-1), a member of the family of neuronal calcium sensor proteins (NCS), modulates a variety of processes in extra-neuronal tissues. In this study, we describe VILIP-1 expression in the human heart, rat cardiomyocytes, and H9c2 cells, and demonstrate that VILIP-1 regulates the cell surface localization of natriuretic peptide receptor B (NPR-B). In preparations from failing hearts, we observed VILIP-1 downregulation and reduced NPR-B signalling. In conclusion, VILIP-1 deficiency may be responsible for the reduced efficiency of the natriuretic peptide system in cardiac hypertrophy and heart failure and may therefore serve as pharmacological target.
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Miocitos Cardíacos/metabolismo , Neurocalcina/fisiología , Receptores del Factor Natriurético Atrial/metabolismo , Animales , Western Blotting , Línea Celular , Células Cultivadas , Electroforesis en Gel de Poliacrilamida , Hemodinámica , Humanos , Inmunohistoquímica , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Neurocalcina/deficiencia , Neurocalcina/genética , Neurocalcina/metabolismo , Reacción en Cadena de la Polimerasa , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/fisiología , Ratas , Ratas Sprague-Dawley , Receptores del Factor Natriurético Atrial/genéticaRESUMEN
BACKGROUND: Stimulation of collateral artery growth is a promising therapeutic option for patients with coronary artery disease. External counterpulsation is a non-invasive technique suggested to promote the growth of myocardial collateral arteries via increase of shear stress. The Art.Net.2 Trial tests invasively and functionally for the first time the hypothesis whether a treatment course with external counterpulsation (over 7 weeks) can induce the growth of myocardial collateral arteries. METHODS: This study is designed as a prospective, controlled, proof-of-concept study. Inclusion criteria are (1) age 40 to 80 years, (2) stable coronary disease, (3) a residual significant stenosis of at least one epicardial artery and (4) a positive ischemic stress-test for the region of interest. As primary endpoint serves the pressure-derived collateral flow index (CFIp), the invasive gold-standard to assess myocardial collateral pathways. CFIp is determined by simultaneous measurement of mean aortic pressure (Pa, mm Hg), distal coronary occlusive (wedge) pressure (Pw, mm Hg) and central venous pressure (Pv, mm Hg). The index is calculated as CFIp=(Pw-Pv)/(Pa-Pv). The pressure derived fractional flow reserve (FFR) and the index of microcirculatory resistance (IMR) are assessed as secondary invasive endpoints to investigate the effect of ECP on the myocardial vasculature. The non-invasive secondary endpoints include symptoms (CCS and NYHA classification), treadmill-testing and analysis of shear-stress related soluble proteins. CONCLUSIONS: The Art.Net.-2 Trial will report within the next months whether direct evidence can be brought that ECP promotes coronary collateral growth in patients with stable angina pectoris.
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Circulación Colateral/fisiología , Enfermedad de la Arteria Coronaria/fisiopatología , Enfermedad de la Arteria Coronaria/terapia , Circulación Coronaria/fisiología , Contrapulsación , Adulto , Anciano , Anciano de 80 o más Años , Presión Venosa Central/fisiología , Vasos Coronarios/fisiología , Prueba de Esfuerzo , Humanos , Persona de Mediana Edad , Pletismografía , Estudios Prospectivos , Resistencia Vascular/fisiologíaRESUMEN
A proper interaction between the endocardial-derived ligand Neuregulin-1 and the myocardial "Human Epidermal growth factor Receptor 2" (HER2) is essential for maintaining heart function. The shed extracellular domain (ECD) of HER2 circulates in blood and serves as a surrogate marker for breast cancer. Altered cardiac loading conditions are accompanied by dysregulation of the myocardial HER2 gene expression. We studied 193 controls with preserved ejection fraction (EF>55%) and 572 patients with different degrees of systolic heart failure: 98 had EF 45-55%, 138 patients EF 35-44%, and 336 patients, EF <35%, respectively. The corresponding mean HER2 levels were 6.44 ± 0.46 ng/mL, 6.07 ± 0.76 ng/mL and 6.57 ± 0.87 ng/mL, and 6.17 ± 0.71 ng/mL, respectively. Furthermore, there was no significant association between plasma HER2 levels and left ventricular filling pressures or the left ventricular wall thickness. The HER2 plasma levels do not reflect the cardiac function and are therefore not useful as a biomarker for heart failure.
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Insuficiencia Cardíaca/sangre , Pruebas de Función Cardíaca , Hipertrofia Ventricular Izquierda/sangre , Receptor ErbB-2/sangre , Anciano , Biomarcadores/sangre , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Persona de Mediana EdadRESUMEN
Takayasu arteritis (TA) is a chronic vasculitis, affecting young women in 80-90% of cases with greatest prevalence in Asians. As exudative pericarditis is an extremely rare, but a possible manifestation of TA, we report on a young women who presented with recurrent febrile pericardial effusion as primary manifestation of TA.
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Derrame Pericárdico/diagnóstico , Arteritis de Takayasu/diagnóstico , Adulto , Diagnóstico Diferencial , Ecocardiografía Transesofágica , Femenino , Humanos , Derrame Pericárdico/diagnóstico por imagen , Arteritis de Takayasu/diagnóstico por imagenRESUMEN
Heart failure (HF) has been identified as one of the most threatening diseases for the western civilisation, posing a risk to health for a rising number of patients. Acknowledging the medical problem of HF to be both economically and socially threatening the German Federal Ministry of Research and Education (BMBF) initiated a nationwide research network aiming to find new ways in prevention, alleviation and treatment of the widespread disease. The "Competence Network Heart Failure" (CNHF), initiated in 2003, bundles the scientific expertise in a large-scale research network; its aims are the coordination of basic and applied clinical research as well as dissemination of findings into clinical practice in order to consolidate and perpetuate the achieved improvements. The scope of this paper is to introduce the CNHF and to provide an overview of the tasks and hitherto attained achievements to a broad spectrum of health care providers.
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Redes Comunitarias/normas , Insuficiencia Cardíaca/terapia , Redes Comunitarias/tendencias , Alemania/epidemiología , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/prevención & control , HumanosRESUMEN
BACKGROUND: Ostium secundum atrial septal defects (ASDII) account for approximately 10% of all congenital heart defects (CHD), and mutations in cardiac transcription factors, including TBX20, were identified as an underlying cause for ASDII. However, very little is known about disease penetrance in families and functional consequences of inherited TBX20 mutations. METHODS: The coding region of TBX20 was directly sequenced in 170 ASDII patients. Functional consequences of one novel mutation were investigated by surface plasmon resonance, CD spectropolarymetry, fluorescence spectrophotometry, luciferase assay and chromatin immunoprecipitation. RESULTS: We found a novel mutation in a highly conserved residue in the T-box DNA binding domain (I121M) segregating with CHD in a three generation kindred. Four mutation carriers revealed cardiac phenotypes in terms of cribriform ASDII, large patent foramen ovale or cardiac valve defects. Interestingly, tertiary hydrophobic interactions within the mutant TBX20 T-box were significantly altered leading to a more dynamic structure of the protein. Moreover, Tbx20-I121M resulted in a significantly enhanced transcriptional activity, which was further increased in the presence of co-transcription factors GATA4/5 and NKX2-5. Occupancy of DNA binding sites on target genes was also increased. CONCLUSIONS: We suggest that TBX20-I121M adopts a more fluid tertiary structure leading to enhanced interactions with cofactors and more stable transcriptional complexes on target DNA sequences. Our data, combined with that of others, suggest that human ASDII may be related to loss-of-function as well as gain-of-function TBX20 mutations.