***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective Dilated cardiomyopathy is the end result of chronic iron overload in patients with beta thalassemia major . The objective of the present study was to evaluate the safety and efficacy of Carvedilol in patients with beta thalassemia major and dilated cardiomyopathy . Methods During a six-month period , fourteen patients with beta-thalassemia major and heart failure without diabetes mellitus referred to pediatric cardiology clinic enrolled in this double blind , r and omly assigned study . All patients were on anti failure therapy with Digoxin , Captopril and Furosemide . Carvedilol was started at a dosage of 3.12 mg bid and for patients who had a systolic blood pressure > 100 mmHg , heart rate > 60/min and no signs of low cardiac output the dosage was increased every two weeks to a maximum of 25 mg bid . Clinical signs and symptoms , systolic and diastolic echocardiographic indexes and Tissue Doppler Imaging ( TDI ) data were collected from each patient . Findings Eight patients received Carvedilol ( Group 1 ) and six received placebo ( Group 2 ) . The mean age of patients in Group1 and 2 were 16±0.7 years and 17±3 years respectively . Only one patent in Group 1 tolerated increasing Carvedilol dosage to more than 6.25 mg bid . Changes in New York Heart Association ( NYHA ) classification , Ejection fraction , End diastolic dimension changes , TDI systolic(S ) , early ( Ea ) and late ( Aa ) diastolic waves were not statistically significant in these two Groups ( P>0.05 ) . Pulse Doppler E/A wave ratio of mitral valve in Group1 and Group 2 changed from 1.1±0.37 m/s to 1.8±0.40 m/s and from 1.34±0.30 m/s to 2.6±0.23 m/s respectively ( P=0.04 ) . Conclusion Patients with thalassemia and dilated cardiomyopathy have poor tolerance to increasing Carvedilol dosage and develop decreased systolic blood pressure during advancement of the drug dosage . Carvedilol can be effective in prevention of progression of diastolic dysfunction in these patients The objective of this study was to evaluate the safety and efficacy of carvedilol in pediatric patients with stable moderate heart failure . We performed a single-arm prospect i ve drug trial at three academic medical centers and the results were compared to historical controls . Patients were 3 months to 17 years old with an ejection fraction < 40 % in the systemic ventricle for at least 3 months on maximal medical therapy including ACE inhibitors .  Treated patients were started on 0.1 mg/kg/day and uptitrated to 0.8 mg/kg/day or the maximal tolerated dose .  Echocardiographic parameters of function were prospect ively measured at entry and at 6 months . Two composite endpoints were recorded : severe decline in status and significant clinical change . Adverse events were review ed by a safety committee . Data were also collected from untreated controls with dilated cardiomyopathy meeting entry criteria , assessed over a similar time frame . Twenty patients [ 12 dilated cardiomyopathy ( DCM ) and 8 congenital ] with a median age of 8.4 years ( range , 8 months to 17.8 years ) were treated with carvedilol .  Three patients discontinued the drug during the study . At entry , there was no statistical difference in age , weight , or ejection fraction between the treated group and controls . The ejection fraction of the treated DCM group improved significantly from entry to 6 months ( median , 31 to 40 % , p = 0.04 ) , with no significant change in ejection fraction in the control group [ median , 29 to 27 % , p = not significant ( NS ) ] . The median increase in ejection fraction was larger for the treated DCM group than for the untreated DCM controls ( 7 vs 0 % , p = 0.05 ) . By Kaplan – Meier analysis , time to death or transplant tended to be longer in treated patients ( p = 0.07 ) . The difference in the proportion of patients with severe decline in status or significant clinical change in the treated group was not significant compared to the controls ( 5 vs 12 % , p = NS ) . We conclude that in this prospect i ve protocol of pediatric patients , the use of adjunct carvedilol in the DCM group improved ejection fraction compared to untreated controls and trended toward delaying time to transplant or death Background and Objectives In Duchenne and Becker muscular dystrophies , cardiac function deteriorates with time result ing in heart failure which is often fatal . We prospect ively evaluated the effect of enalapril and carvedilol on left ventricular ( LV ) dysfunction in middle childhood and adolescent patients with muscular dystrophy . Subjects and Methods Twenty-three patients with LV dysfunction ( 22 with Duchenne muscular dystrophy , 1 with Becker muscular dystrophy ) were enrolled . We prescribed enalapril ( 13 patients ) or carvedilol ( 10 patients ) r and omly from July 2008 to August 2010 and followed up the patients until September 2011 . The changes in LV function parameters before and after the treatment were evaluated by echocardiography . Results The mean age at the start of treatment with enalapril or carvedilol  was 12.6±3.7 years ( median 13 years ) , and mean follow-up duration was 20.1±8.9 months . In the enalapril group , LV fractional shortening ( FS ) increased from 25.8±2.1 to 26.6±3.0 ( p=0.241 ) . In the carvedilol group , LV FS increased from 26.4±1.1 to 28.6±4.2 ( p=0.110 ) . In all 23 patients , LV FS significantly increased from 26.1±1.7 ( before ) to 27.6±3.7 ( after treatment ) ( p<0.046 ) . Indexed LV dimension at end diastole and LV end-diastolic volume decreased slightly , but without statistical significance by tri-plane volumetry . LV diastolic functional parameters were maintained during follow-up period . Conclusion Enalapril or carvedilol could improve LV systolic function in middle childhood and adolescent patients with muscular dystrophy without significant adverse effects The aim of this study was to assess the effect ofmetoprolol on cardiac function in children with heart failure . This r and omized double-blind placebo controlled clinical trial was performed in children with heart failure due to left ventricle volume overload structural heart disease such as VSD , PDA , AI and MR who referred to pediatric cardiology clinics in sari in 2007 . The patients divided into case and control groups . All cases were matched as viewpoints of age , sex , weight , kinds of primary disease and cardiac drugs ( except for metoprolol).Metoprolol with single daily dose of 1 mg kg(-1 ) and placebo were given to patients in case and control groups respectively . Echocardiography with cardiac indices of systolic and diastolic function was done as baseline and monthly for 3 months in all the patients . Data were analyzed using SPSS software and statistical t-test . Thirty patients ( 16 cases and 14 controls ) were enrolled in the study .  CI , MPI and dv/dt ( dt ) decreased significantly at first month . Significant changes in LVEF and EPSS appeared on the second month and in E wave and E/A appeared on the third month . The results were in favor of systolic and diastolic improvement .  Metoprolol causes improvement of cardiac systolic and diastolic function in children with heart failure due to cardiac defect . Therefore , metoprolol is recommended in patients with heart failure in above mentioned diseases that have not been controlled adequately in spite of receiving st and ard cardiac failure drug therapy such as an inotrope , a diuretic and a vasodilator agent OBJECTIVE The objective was to determine the dosing , efficacy , and side effects of the nonselective beta-blocker carvedilol for the management of heart failure in children . STUDY DESIGN Carvedilol use in addition to st and ard medical therapy for pediatric heart failure was review ed at 6 centers . RESULTS Children with dilated cardiomyopathy ( 80 % ) and congenital heart disease ( 20 % ) , age 3 months to 19 years ( n = 46 ) , were treated with carvedilol . The average initial dose was 0.08 mg/kg , uptitrated over a mean of 11.3 weeks to an average maintenance dose of 0.46 mg/kg . After 3 months on carvedilol , there were improvements in modified New York Heart Association class in 67 % of patients ( P = .0005 , chi2 analysis ) and improvement in mean shortening fraction from 16.2 % to 19.0 % ( P = .005 , paired t test ) . Side effects , mainly dizziness , hypotension , and headache , occurred in 54 % of patients but were well tolerated . Adverse outcomes ( death , cardiac transplantation , and ventricular-assist device placement ) occurred in 30 % of patients . CONCLUSIONS Carvedilol as an adjunct to st and ard therapy for pediatric heart failure improves symptoms and left ventricular function . Side effects are common but well tolerated . Further prospect i ve study is required to determine the effect of carvedilol on survival and to clearly define its role in pediatric heart failure therapy OBJECTIVE Endocardial fibroelastosis ( EFE ) , a common pediatric cardiovascular disease , often results in chronic heart failure ( CHF ) and death . Clinical trials have shown that the regimen of combining beta-adrenoreceptor blocker with traditional medicines against CHF can improve left ventricular function and prevent the ventricle from remodeling in patients with CHF . The present study aim ed to observe the effect of carvedilol on concentration of plasma brain-type natriuretic peptide ( BNP ) , and safety in children with EFE . METHODS Twenty-one children with EFE were r and omly divided into two groups : ( 1 ) treated with traditional regimen ( digoxin , prednisone and /or diuretics ) ( n = 10 ) ; ( 2 ) treated with carvedilol plus traditional regimen ( n = 11 ) . Measurement of plasma concentration of BNP by ELISA , cardiac function by ultrasound were performed before and after 6 months of treatment . The changes in clinical symptom , heart rate , heart function , side effect and maximal tolerance dose after treatment with carvedilol were observed . RESULTS Plasma concentration of BNP was much higher in the group of patients with EFE [ ( 865 + /- 702 ) ng/L ] than that of control group [ ( 154 + /- 78 ) ng/L ] ( P < 0.01 ) , and there was a positive correlation between plasma concentration of BNP and cardiac function classification , and cardiac function grade s II , III , and IV corresponded to plasma concentration of BNP ( 286 + /- 125 ) ng/L , ( 437 + /- 386 ) ng/L , ( 1673 + /- 859 ) ng/L respectively in children with EFE . Compared with the group treated with traditional medicines , plasma concentration of BNP [ ( 403 + /- 216 ) ng/L vs. ( 219 + /- 87 ) ng/L ] significantly decreased , the clinical symptom was significantly improved , cardio-thoracic ratio ( CTR ) ( 0.60 + /- 0.05 vs. 0.54 + /- 0.06 ) ( P < 0.05 ) and heart rate [ ( 115 + /- 20 ) bpm vs. ( 90 + /- 14 ) bpm ] ( P < 0.01 ) decreased , ejection fraction ( EF ) ( 46.6 % + /- 13.4 % vs. 54.5 % + /- 12.9 % ) , fractional shortening ( 21.6 % + /- 8.1 % vs. 24.1 % + /- 7.5 % ) , mean velocity of circumferential fiber shortening [ ( 0.8 + /- 0.5 ) cir/s vs. ( 0.9 + /- 0.4 ) cir/s ] were significantly increased ( P < 0.01 ) , left ventricular end-systolic dimension [ ( 34.0 + /- 8.6 ) mm vs. ( 32.2 + /- 9.1 ) mm ] ( P < 0.05 ) , left ventricular mass [ ( 65.9 + /- 34.1 ) g vs. ( 65.9 + /- 34.1 ) g ] , interventricular septal thickness at end-systole [ ( 6.0 + /- 1.0 ) mm vs ( 5.5 + /- 1.1 ) mm ] were notably decreased ( P < 0.01 ) after treatment with carvedilol . CONCLUSION These data indicated that plasma concentration of BNP significantly increased in children with EFE , carvedilol can decrease plasma concentration of BNP , inhibit the remodeling of ventricle , significantly improve the cardiac function in children with EFE . Carvedilol is effective and safe in treatment of children with EFE OBJECTIVE Our purpose was to evaluate the clinical effect of carvedilol among pediatric patients with congestive heart failure ( CHF ) who did not respond to st and ard therapy and to assess the  pharmacokinetics of  carvedilol  among these children . METHODS In this prospect i ve , open intervention trial with blinded interpretation of selected end points , patients with CHF who did 
    Output:
    
A larger study with 161 participants showed no evidence of benefit over placebo in a composite measure of heart failure outcomes .
The included studies showed no significant difference in mortality or heart transplantation rates between the beta-blocker and control groups .
No significant adverse events were reported with beta-blockers , apart from one episode of complete heart block .
A meta- analysis of left ventricular ejection fraction ( LVEF ) and fractional shortening ( LVFS ) data showed a very small improvement with beta-blockers .
There is not enough evidence to support or discourage the use of beta-blockers in children with congestive heart failure , or to propose a paediatric dosing scheme .
However , the sparse data available suggested that children with congestive heart failure might benefit from beta-blocker treatment .