Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure .
Using mean values in these trials , the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification .
The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy .
The results of the 6MWT were concordant with changes in symptoms , suggesting that it may be used as supportive evidence for symptom benefit .
AIMS The 6 min walk test ( 6MWT ) is commonly used in clinical trials to assess treatments for heart failure , but its ability to distinguish between effective and ineffective treatments is question able .
The aim of this study is to investigate , using a systematic literature review , the utility of the 6MWT as a measure of the effectiveness of treatment in r and omized controlled trials of heart failure .
Atriobiventricular pacing improves exercise capacity in patients with heart failure and intraventricular conduction delay.
OBJECTIVES We sought to assess the efficacy of biventricular pacing with respect to both peak and submaximal measures of exercise in patients with New York Heart Association class III heart failure ( HF ) and intraventricular conduction delay in a r and omized , blinded study . BACKGROUND Submaximal and maximal changes in exercise capacity need evaluating in this patient population with this novel therapy . METHODS Grade d exercise and 6-min walk tests were performed in patients r and omized to three months each of active ( atrio-biventricular ) and inactive pacing .  Minute ventilation ( VE ) , oxygen uptake ( VO(2 ) ) , ventilated carbon dioxide ( VCO(2 ) ) and heart rate were measured in patients achieving a respiratory quotient > 1 ( n = 30 ) . Oxygen pulse , anaerobic threshold ( AT ) and ventilatory efficiency ( VE/VCO(2 ) ) were calculated . RESULTS Active biventricular pacing increased peak VO(2 ) ( 15.8 + /- 4.3 vs. 14.4 + /- 4.6 ml/kg/min , p = 0.02 ) , exercise time ( 501 + /- 223 s vs. 437 + /- 233 s , p < 0.001 ) and oxygen pulse ( 9.3 + /- 2.8 vs. 8.1 + /- 3.1 ml/beat , p < 0.01 ) compared with inactive pacing . The submaximal measures of exercise capacity significantly increased with active pacing : AT ( 11.2 + /- 4.1 ml/kg/min vs. 9.5 + /- 2.3 ml/kg/min , p = 0.02 ) and 6-min walk ( 414 + /- 94 m vs. 359 + /- 94 m , p = 0.001 ) . Minute ventilation/ventilated carbon dioxide improved ( 32 + /- 9 vs. 36 + /- 11 , p = 0.03 ) with normalization of the VE/VCO(2 ) slope in 59 % of patients ( chi-square test , p = 0.002 ) with active pacing . CONCLUSIONS Biventricular pacing may improve maximal and submaximal exercise capacity in patients with advanced HF and intraventricular conduction delay
Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure .
Using mean values in these trials , the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification .
The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy .
The results of the 6MWT were concordant with changes in symptoms , suggesting that it may be used as supportive evidence for symptom benefit .
AIMS The 6 min walk test ( 6MWT ) is commonly used in clinical trials to assess treatments for heart failure , but its ability to distinguish between effective and ineffective treatments is question able .
The aim of this study is to investigate , using a systematic literature review , the utility of the 6MWT as a measure of the effectiveness of treatment in r and omized controlled trials of heart failure .