Clinical results
Table 2shows the results for the 69 patients who completed the crossover period. With active pacing, peak Vo2 increased 1.37 ml/min/kg (95% confidence interval [CI] 1.99 to 0.76; p < 0.001) (Fig. 2A), and Vo2 at the anaerobic threshold increased 0.87 ml/min/kg (95% CI 1.35 to 0.40; p < 0.001), compared with inactive pacing. The distance walked in 6 min was 26 m longer with active pacing (95% CI 48 to 5; p = 0.021). The quality-of-life score improved 4.7 points with active pacing (95% CI 8.5 to 0.9; p = 0.015). The NYHA functional class significantly improved by 0.25 class points with active pacing (95% CI 0.38 to 0.11; p = 0.001). No carryover or period effects were observed. There were no significant differences in any end point improvement between patients with a pacemaker and patients with an ICD, or between patients paced with LV coronary vein leads and those with epicardial screw-in leads.