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 .
Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: prospective haemodynamic study
Objective : To compare clinical and haemodynamic variables between left ventricular and biventricular pacing in patients with severe heart failure ; and to analyse haemodynamic changes during daily life and maximum exercise during chronic left ventricular and biventricular pacing . Design : Prospect i ve single blinded r and omised study with crossover . Setting : University hospital ( tertiary referral centre ) . Patients and methods : 13 patients ( mean ( SD ) age , 62 ( 6 ) years ) with chronic atrial fibrillation , severe heart failure ( mean ejection fraction 24 (8)% ) , and QRS prolongation of ≥ 140 ms had His bundle ablation and installation of a pacemaker providing left ventricular and biventricular pacing . The pacemaker was equipped with a peak endocardial acceleration ( PEA ) sensor . The PEA pattern was used as a haemodynamic marker during exercise as it is highly correlated with left ventricular dP/dt . After a baseline period of right ventricular pacing , all patients had two months of left ventricular pacing and two months of biventricular pacing in r and om order . At the end of each phase , an echocardiogram , a haemodynamic analysis at rest and on exercise during a six minute walk test , and a cardiopulmonary exercise test were performed . Results : PEA values were higher with left ventricular pacing ( 0.58 ( 0.38 ) m/s ) and biventricular pacing ( 0.62 ( 0.24 ) m/s ) than at baseline ( 0.49 ( 0.18 ) m/s ) ( p < 0.05 ) . The six minute walk test showed similar performance in both pacing modes , but patients had more symptoms with left ventricular pacing at the end of the test ( p = 0.035 ) . On cardiopulmonary exercise testing , there was a greater increase in mean percentage variation of PEA with biventricular pacing than with left ventricular pacing ( 125 (18)% v 97 (36)% , respectively ; p = 0.048 ) and better performance figures ( 92 ( 34 ) W v 77 ( 23 ) W ; p = 0.03 ) . Conclusions : During symptom limited and daily life exercise tests , chronic biventricular pacing  provides better haemodynamic performance  than left ventricular pacing . In heart failure patients with wide QRS complexes , the interventricular dyssynchronisation induced by left ventricular pacing may impair myocardial function during exercise
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 .