Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Circ Genom Precis Med ; 16(5): 434-441, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37593875

RESUMEN

BACKGROUND: Variants in RBM20 are reported in 2% to 6% of familial cases of dilated cardiomyopathy and may be associated with fatal ventricular arrhythmia and rapid heart failure progression. We sought to determine the risk of adverse events in RBM20 variant carriers and the impact of sex on outcomes. METHODS: Consecutive probands and relatives carrying RBM20 variants were retrospectively recruited from 12 cardiomyopathy units. The primary end point was a composite of malignant ventricular arrhythmia (MVA) and end-stage heart failure (ESHF). MVA and ESHF end points were also analyzed separately and men and women compared. Left ventricular ejection fraction (LVEF) contemporary to MVA was examined. RBM20 variant carriers with left ventricular systolic dysfunction (RBM20LVSD) were compared with variant-elusive patients with idiopathic left ventricular systolic dysfunction. RESULTS: Longitudinal follow-up data were available for 143 RBM20 variant carriers (71 men; median age, 35.5 years); 7 of 143 had an MVA event at baseline. Thirty of 136 without baseline MVA (22.0%) reached the primary end point, and 16 of 136 (11.8%) had new MVA with no significant difference between men and women (log-rank P=0.07 and P=0.98, respectively). Twenty of 143 (14.0%) developed ESHF (17 men and 3 women; log-rank P<0.001). Four of 10 variant carriers with available LVEF contemporary to MVA had an LVEF >35%. At 5 years, 15 of 67 (22.4%) RBM20LVSD versus 7 of 197 (3.6%) patients with idiopathic left ventricular systolic dysfunction had reached the primary end point (log-rank P<0.001). RBM20 variant carriage conferred a 6.0-fold increase in risk of the primary end point. CONCLUSIONS: RBM20 variants are associated with a high risk of MVA and ESHF compared with idiopathic left ventricular systolic dysfunction. The risk of MVA in male and female RBM20 variant carriers is similar, but male sex is strongly associated with ESHF.


Asunto(s)
Insuficiencia Cardíaca , Disfunción Ventricular Izquierda , Adulto , Femenino , Humanos , Masculino , Arritmias Cardíacas , Insuficiencia Cardíaca/genética , Estudios Retrospectivos , Volumen Sistólico , Disfunción Ventricular Izquierda/genética , Función Ventricular Izquierda
2.
ESC Heart Fail ; 10(1): 234-244, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36193570

RESUMEN

AIMS: Wild-type transthyretin cardiac amyloidosis (ATTRwt) is an infiltrative cardiomyopathy with a poor prognosis. The condition is associated with carpal tunnel syndrome (CTS), which often precedes the ATTRwt diagnosis by several years. The aim of the study was (i) to screen patients with a recent history of CTS for ATTRwt using red flags, (ii) to determine whether patients with screened ATTRwt had less advanced disease compared with patients with clinical ATTRwt, and (iii) to assess the sensitivity and specificity of known red flags in ATTRwt. METHODS AND RESULTS: Patients aged ≥60 years at the time of CTS surgery were invited for screening. Red flags were defined as elevated biomarker levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) or cardiac troponin, an electrocardiogram pattern associated with ATTRwt, left ventricular hypertrophy (LVH), and impaired longitudinal strain with apical sparring. All patients with a red flag were referred for a diagnostic scintigraphy. Patients with ATTRwt diagnosed by screening were compared with patients with clinical ATTRwt (n = 51) matched by age, gender, and CTS surgery. Among the 120 enrolled subjects (mean age 74.5 years, 90% male), the suspicion of ATTR was raised in 67 (55.8%), and 10 (8.3%) were diagnosed with ATTRwt. Patients identified with ATTRwt were predominantly asymptomatic and had mildly elevated NT-proBNP, mildly increased LVH, preserved left ventricular ejection fraction, and systolic longitudinal function, which differed significantly from clinical ATTRwt controls (P < 0.001). CONCLUSIONS: The study found an ATTRwt prevalence of 8.3% in a population of age and gender-selected patients with a recent history of CTS. The identified patients with ATTRwt had less structural and functional cardiac involvement than clinical ATTRwt controls.


Asunto(s)
Amiloidosis , Síndrome del Túnel Carpiano , Anciano , Femenino , Humanos , Masculino , Amiloidosis/complicaciones , Síndrome del Túnel Carpiano/complicaciones , Síndrome del Túnel Carpiano/epidemiología , Síndrome del Túnel Carpiano/cirugía , Hipertrofia Ventricular Izquierda , Prealbúmina , Volumen Sistólico , Función Ventricular Izquierda
3.
J Am Soc Echocardiogr ; 36(2): 196-204, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36444740

RESUMEN

BACKGROUND: Patients with obstructive hypertrophic cardiomyopathy (HCM) often experience symptoms of heart failure upon exertion despite having normal left ventricular (LV) ejection fractions. Longitudinal strain (LS) may be a more sensitive marker of systolic dysfunction in patients with LV hypertrophy. The aims of this study were to characterize LV segmental LS and global LS (GLS) at rest and during exercise and to assess if first-line treatment with ß-blockers improves LV systolic performance. METHODS: Twenty-nine patients with obstructive HCM and New York Heart Association functional class ≥ II symptoms were enrolled in a double-blind, placebo-controlled, randomized crossover trial. Patients received metoprolol 150 mg or placebo for two consecutive 2-week periods in random order. Echocardiographic assessment with speckle-tracking-derived LS was performed at rest and during peak exercise at the end of each treatment period. RESULTS: During placebo treatment, resting values of segmental LS showed an apical-basal difference of -10.3% (95% CI, -12.7% to -7.8%; P < .0001), with a severely abnormal value of the basal segment of -9.3 ± 4.2%. Treatment with metoprolol was associated with more negative LS values of the apical segment (-2.8%; 95% CI, -4.2% to -1.3%; P < .001) and the mid segment (-1.1%; 95% CI, -2.0% to -0.3%; P = .007). During peak exercise there was a deterioration in LV GLS, but treatment with metoprolol was associated with more negative peak exercise LV GLS (-1.3 %; 95% CI, -2.6% to -0.1%; P = .03). CONCLUSIONS: Systolic performance assessed by LV GLS showed impaired values at rest and during exercise, with severely depressed values of the basal and mid segments. Treatment with metoprolol improved LV GLS upon exercise, indicating a beneficial effect of ß-blocker treatment on LV systolic function.


Asunto(s)
Cardiomiopatía Hipertrófica , Disfunción Ventricular Izquierda , Humanos , Metoprolol/uso terapéutico , Cardiomiopatía Hipertrófica/diagnóstico por imagen , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Ventrículos Cardíacos/diagnóstico por imagen , Ecocardiografía , Función Ventricular Izquierda , Antagonistas Adrenérgicos beta/farmacología , Antagonistas Adrenérgicos beta/uso terapéutico , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/tratamiento farmacológico
4.
ESC Heart Fail ; 9(5): 2978-2987, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35733407

RESUMEN

BACKGROUND: Prognostic markers of survival have been identified in wild-type transthyretin amyloidosis (ATTRwt), but limited data exist with respect to hospitalizations with worsening heart failure (WHF). Predictive markers of WHF have yet to be identified. METHODS: From April 2017 to February 2021, 104 patients with ATTRwt were diagnosed and prospectively followed from the time of diagnosis to the time of death or the censoring date of 1 February 2021. Baseline patient characteristics, biomarkers, and advanced echocardiography were used to predict hospitalization with WHF. RESULTS: During the median follow-up period of 23 months, 51% of patients were hospitalized due to WHF. Seventy-three per cent of patients with WHF were admitted at least twice. Patients with WHF during the first year had significantly poorer survival (P < 0.001). Independent predictors of WHF during follow-up were pacemaker implantation prior to diagnosis (PMI, P = 0.037) and right atrial volume index (RAVi, P = 0.008). Patients with PMI had a higher left ventricular mass index and poorer left ventricular and right ventricular systolic function indicating a more advanced stage of amyloid disease. CONCLUSIONS: A high incidence and recurrence of hospital admissions with WHF were demonstrated in contemporary patients with ATTRwt, which was associated with reduced survival. Patients with pacemaker devices prior to ATTRwt diagnosis experienced more frequent hospitalizations with WHF. PMI and right atrial enlargement were identified as independent predictors of WHF during follow-up.


Asunto(s)
Neuropatías Amiloides Familiares , Insuficiencia Cardíaca , Humanos , Prealbúmina , Incidencia , Neuropatías Amiloides Familiares/complicaciones , Neuropatías Amiloides Familiares/diagnóstico , Neuropatías Amiloides Familiares/epidemiología , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/etiología , Ecocardiografía
5.
J Am Coll Cardiol ; 79(16): 1565-1575, 2022 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-35450573

RESUMEN

BACKGROUND: The relationship between exercise hemodynamics, loading conditions, and medical treatment in patients with obstructive hypertrophic cardiomyopathy (HCM) is incompletely understood. OBJECTIVES: This study aimed to investigate the effect of metoprolol on invasive hemodynamic parameters at rest and during exercise in patients with obstructive HCM. METHODS: This randomized, double-blind, placebo-controlled crossover trial enrolled 28 patients with obstructive HCM and New York Heart Association functional class ≥II. Patients were randomized to initiate either metoprolol 150 mg or placebo for 2 consecutive 2-week periods. Right-heart catheterization and echocardiography were performed at rest and during exercise at the end of each treatment period. The primary outcome was the difference in pulmonary capillary wedge pressure (ΔPCWP) between peak exercise and rest. RESULTS: No treatment effect on ΔPCWP was observed between metoprolol and placebo treatment (21 ± 9 mm Hg vs 23 ± 9 mm Hg; P = 0.12). At rest, metoprolol lowered heart rate (P < 0.0001), left ventricular outflow tract (LVOT) gradient (P = 0.01), and increased left ventricular end-diastolic volume (P = 0.02) and stroke volume (SV) (+6.4; 95% CI: 0.02-17.7; P = 0.049). During peak exercise, metoprolol was associated with a lower heart rate (P < 0.0001), a lower LVOT gradient (P = 0.0005), lesser degree of mitral regurgitation (P = 0.004), and increased SV (+9 mL; 95% CI: 2-15 mL; P = 0.008). CONCLUSIONS: In patients with obstructive HCM, exercise was associated with an abnormal rise in PCWP, which was unaffected by metoprolol. However, metoprolol increased SV at rest and peak exercise following changes in end-diastolic volume, LVOT gradient, and degree of mitral regurgitation. (The Effect of Metoprolol in Patients With Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).


Asunto(s)
Cardiomiopatía Hipertrófica , Insuficiencia de la Válvula Mitral , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/diagnóstico por imagen , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Hemodinámica/fisiología , Humanos , Metoprolol/farmacología , Metoprolol/uso terapéutico , Insuficiencia de la Válvula Mitral/complicaciones , Volumen Sistólico/fisiología
6.
J Am Coll Cardiol ; 78(25): 2505-2517, 2021 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-34915981

RESUMEN

BACKGROUND: The use of ß-adrenergic receptor blocking agents in symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) rests on clinical experience and observational cohort studies. OBJECTIVES: This study aimed to investigate the effects of metoprolol on left ventricular outflow tract (LVOT) obstruction, symptoms, and exercise capacity in patients with obstructive HCM. METHODS: This double-blind, placebo-controlled, randomized crossover trial enrolled 29 patients with obstructive HCM and New York Heart Association (NYHA) functional class II or higher symptoms from May 2018 to September 2020. Patients received metoprolol or placebo for 2 consecutive 2-week periods in random order. The effect parameters were LVOT gradients, NYHA functional class, Canadian Cardiovascular Society (CCS) angina class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and cardiopulmonary exercise testing. RESULTS: Compared with placebo, the LVOT gradient during metoprolol was lower at rest (25 mm Hg [interquartile range (IQR): 15-58 mm Hg] vs 72 mm Hg [IQR: 28-87 mm Hg]; P = 0.007), at peak exercise (28 mm Hg [IQR: 18-40 mm Hg] vs 62 mm Hg [IQR: 31-113 mm Hg]; P < 0.001), and postexercise (45 mm Hg [IQR: 24-100 mm Hg] vs 115 mm Hg [IQR: 55-171 mm Hg]; P < 0.0001). During metoprolol treatment, 14% of patients were in NYHA functional class III or higher compared with 38% of patients receiving placebo (P < 0.01). Similarly, no patients were in CCS class III or higher during metoprolol treatment compared with 10% during placebo treatment (P < 0.01). These findings were confirmed by higher KCCQ-OSS during metoprolol treatment (76.2 ± 16.2 vs 73.8 ± 19.5; P = 0.039). Measures of exercise capacity, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide did not differ between the study arms. CONCLUSIONS: Compared with placebo, metoprolol reduced LVOT obstruction at rest and during exercise, provided symptom relief, and improved quality of life in patients with obstructive HCM. Maximum exercise capacity remained unchanged. (The Effect of Metoprolol in Patients with Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Metoprolol/uso terapéutico , Obstrucción del Flujo Ventricular Externo/tratamiento farmacológico , Antagonistas de Receptores Adrenérgicos beta 1/farmacología , Anciano , Cardiomiopatía Hipertrófica/complicaciones , Estudios Cruzados , Método Doble Ciego , Tolerancia al Ejercicio/efectos de los fármacos , Femenino , Humanos , Masculino , Metoprolol/farmacología , Persona de Mediana Edad , Obstrucción del Flujo Ventricular Externo/etiología
7.
J Med Genet ; 58(12): 832-841, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-33106378

RESUMEN

BACKGROUND: Truncating variants in titin (TTNtv) are the most common cause of dilated cardiomyopathy (DCM). We evaluated the genotype-phenotype correlation in TTNtv-DCM, with a special focus on long-term outcomes, arrhythmias, response to treatment and sex-related presentation. METHODS: Data on patient characteristics and outcomes were collected retrospectively from electronic health records of patients genotyped at two Danish heart transplantation centres. RESULTS: We included 115 patients (66% men). At diagnosis of DCM, mean age was 46±13 years and left ventricular ejection fraction (LVEF) was 28%±13%. During a median follow-up of 7.9 years, 26% reached a composite outcome of left ventricular assist device implantation, heart transplantation or death. In 20% an arrhythmia preceded the DCM diagnosis. In total, 43% had atrial fibrillation (AF) and 23% had ventricular arrhythmias. Long-term left ventricular reverse remodelling (LVRR; LVEF increase ≥10% points or normalisation) was achieved in 58% and occurred more frequently in women (72% vs 51%, p=0.042).In multivariable proportional hazards analyses, occurrence of LVRR was a strong independent negative predictor of the composite outcome (HR: 0.05 (95% CI 0.02 to 0.14); p<0.001). Female sex independently predicted lower rates of ventricular arrhythmias (HR: 0.33 (95% CI 0.11 to 0.99); p=0.05), while the location of the TTNtv was not associated with cardiovascular outcomes. CONCLUSION: DCM caused by TTNtv presented in midlife and was associated with a high burden of AF and ventricular arrhythmias, which often preceded DCM diagnosis. Furthermore, LVRR occurred in a high proportion of patients and was a strong negative predictor of the composite outcome. Female sex was positively associated with occurrence of LVRR and longer event-free survival.


Asunto(s)
Arritmias Cardíacas/genética , Cardiomiopatía Dilatada/genética , Conectina/genética , Predisposición Genética a la Enfermedad/genética , Mutación , Adulto , Anciano , Arritmias Cardíacas/fisiopatología , Cardiomiopatía Dilatada/fisiopatología , Cardiomiopatía Dilatada/terapia , Dinamarca , Femenino , Estudios de Asociación Genética/métodos , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/fisiopatología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud/métodos , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Estudios Retrospectivos , Factores Sexuales , Función Ventricular Izquierda/genética
8.
J Am Soc Echocardiogr ; 33(12): 1465-1473, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32919852

RESUMEN

BACKGROUND: The aim of this study was to investigate the preoperative prevalence, relation to symptoms, and prognostic implications of elevated left ventricular (LV) apical-to-basal strain ratio (ABr) in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement. METHODS: A total of 499 contemporary consecutive patients with AS treated with transcatheter aortic valve replacement were retrospectively included. Patients were included if they underwent preoperative echocardiography with adequate image quality for assessment of LV global longitudinal strain. Baseline clinical and echocardiographic data were collected and analyzed in ABr subgroups. From two-dimensional echocardiographic apical images, ABr was calculated as mean longitudinal strain of the five LV apical segments divided by the mean of the six basal segments. RESULTS: Median follow-up time was 743 days. Mean age was 79.8 ± 7 years. The prevalence of severely increased ABr ≥4 was 16% (n = 78). Patients with ABr ≥4 had higher preoperative New York Heart Association functional class; 77% of those with ABr ≥4 were in New York Heart Association functional class III or IV compared with 59% of those with ABr of 0 to 1.9 (P < .01). Median preoperative N-terminal pro-brain natriuretic peptide level in patients with ABr ≥4 was 1,781 pmol/L, compared with 876 pmol/L in those with ABr of 0 to 1.9 (P = .003). N-terminal pro-brain natriuretic peptide levels at 3-month follow-up remained considerably elevated in patients with ABr ≥4 (the median in patients with ABr ≥4 was 1,262 pmol/L vs 645 pmol/L in those with ABr of 0 to 1.9, P < .01). AS severity was comparable across ABr subgroup levels. Overall, increased ABr ≥4 was associated with poor survival, as overall 3-year survival was 67% among patients with ABr ≥4 compared with 83% in those with ABr of 2 to 3.9 and 86% in those with ABr of 0 to 1.9 (P = .04). CONCLUSION: Among patients with increased ABr ≥4, pre- and postoperative New York Heart Association functional class, serum N-terminal pro-brain natriuretic peptide level, and mortality were significantly increased, and ABr may thus serve as a new echocardiographic marker of high mortality risk among patients with AS treated with transcatheter aortic valve replacement.


Asunto(s)
Estenosis de la Válvula Aórtica , Reemplazo de la Válvula Aórtica Transcatéter , Anciano , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/cirugía , Humanos , Péptido Natriurético Encefálico , Prevalencia , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Función Ventricular Izquierda
9.
Int J Cardiol ; 304: 138-143, 2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32033783

RESUMEN

AIM: To determine the diagnostic delay in patients with wild-type transthyretin cardiac amyloiodosis (ATTRwt). To determine the clinical and echocardiogtraphic characteristics of patients with an early and a late diagnosis and to study the suspected diagnoses and identification of diagnostic "red flags" before the ATTRwt diagnosis was established. METHODS: In 50 consecutive patients with ATTRwt diagnosed from 2017 to 2019, clinical and echocardiographic patient characteristics were investigated based on electronic patient charts and echocardiographic database review at Aarhus University Hospital, Denmark. RESULTS: The median diagnostic delay was 13 months (2-47 months) and a diagnostic delay above 3 months was associated with more advanced symptoms and left ventricular (LV) diastolic dysfunction at the time of the diagnosis. Thirty patients (60%) were investigated for at least two non-ATTRwt diagnoses during the time period from the first cardiac examination to the time of the confirmed diagnosis. ATTR red flags were significantly less used in patients with the longest diagnostic delay (p < 0.001). Abormal LV global longitudinal strain (LV-GLS < 18%) and apical sparring ratio (APSR ≥ 1.5) were present in 96% and 94% of the ATTRwt patients, respectively. CONCLUSION: The diagnostic delay in ATTRwt was substantial and a prolonged diagnostic delay was associated with more advanced symptoms and LV diastolic dysfunction at the time of the diagnosis. Established ATTR red flags are poorly utilized in the diagnostic process. Echocardiographic analysis of LV-GLS and APSR contributes significantly to the evaluation of LV myocardial performance and helps raise the suspicion of ATTRwt.


Asunto(s)
Neuropatías Amiloides Familiares , Cardiomiopatías , Neuropatías Amiloides Familiares/diagnóstico por imagen , Cardiomiopatías/diagnóstico por imagen , Diagnóstico Tardío , Ecocardiografía , Ventrículos Cardíacos , Humanos , Prealbúmina
10.
BMJ Case Rep ; 20162016 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-27605198

RESUMEN

A 47-year-old woman had been treated with high-dose simvastatin for several years. After systemic treatment with the antifungal agent itraconazole, she developed muscle pain and highly elevated levels of creatine kinase and myoglobin. Muscle biopsy was compatible with statin-associated rhabdomyolysis, probably caused by a drug-drug interaction between simvastatin and itraconazole. The patient made full recovery. Three commonly used statins-simvastatin, atorvastatin and lovastatin-are metabolised by the liver enzyme CYP3A4. Several potent inhibitors of this enzyme are known, for example, azole antifungal agents such as itraconazole and posaconazole. If antifungal treatment is indicated in a patient using a CYP3A4-metabolised statin, we recommend (1) topical administration of the antifungal agent if possible, (2) the use of a non-CYP3A4-inhibiting antifungal drug such as terbinafine or (3) temporary discontinuation of statin treatment.


Asunto(s)
Anticolesterolemiantes/efectos adversos , Antifúngicos/efectos adversos , Itraconazol/efectos adversos , Rabdomiólisis/inducido químicamente , Simvastatina/efectos adversos , Interacciones Farmacológicas , Femenino , Humanos , Persona de Mediana Edad , Polifarmacia
11.
Ugeskr Laeger ; 174(13): 865-70, 2012 Mar 26.
Artículo en Danés | MEDLINE | ID: mdl-22456174

RESUMEN

The role of lymphadenectomy in the treatment of epithelial ovarian cancer has been the object of controversy for years. The effect regarding stage and prognosis has been systematically reviewed through the existing literature. Lymphadenectomy gives a better clinical staging and is correlated with a better survival, but causes more surgical complications. It is advisable that all women with epithelial ovarian cancer have lymphadenectomy performed, thus ensuring a correct staging and thereby the optimal treatment.


Asunto(s)
Escisión del Ganglio Linfático , Neoplasias Glandulares y Epiteliales/cirugía , Neoplasias Ováricas/cirugía , Progresión de la Enfermedad , Femenino , Humanos , Escisión del Ganglio Linfático/efectos adversos , Metástasis Linfática , Estadificación de Neoplasias , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Ováricas/patología , Pronóstico , Tasa de Supervivencia , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA