Orsbourn et al. also reported on the use of dual-chamber pacing in seven of the 23 patients they studied.42 Lepillier et al. followed eight patients with complete heart block and heart failure who had temporary dual-chamber pacemakers placed and observed an improvement in heart failure symptoms and brain natriuretic peptide levels.40 Level of activity was reported in 10 studies (Table 4). This evidence concerns the gene NPPB and heart failure.