Beta-blocker therapy in chronic heart failure: how do we treat patients With bradycardia?

Upward titration of beta-blockers in patients with chronic heart failure(CHF) is often limited by bradycardia. It is, however, controversial whether we should implant a pacemaker solely to achieve higher doses of beta-blockers or to give up the upward titration because conventional ventricular pacing causes asynchronous contraction. Therefore, we studied the prognosis in stable CHF patients treated with beta-blockers and who had bradycardia before or during the upward titration. A total of 20 CHF patients(NYHA class II-III) with bradycardia were retrospectively reviewed and were devided into two groups: In 11 patients, upward titration of beta-blockers was stopped due to bradycardia(B group). In 9 patients, pacemakers were implanted before or during upward titration(P group). All patients had a left ventricular ejection fraction of 40% or less and were followed up for 12-40 months(mean 23months). The baseline characteristics of the patients were similar in the two groups. The final doses of beta-blockers were higher in P group than in B group. The rate of hospitalization for worsening heart failure was significantly higher in P group than in B group although there is no difference in all-cause mortality between two groups.Conclusions:(1) The beneficial effects of beta-blockers may not overcome unfavorable effects of conventional ventricular pacemakers in mild to moderate CHF patients. (2) Cardiac resynchronization therapy may be a good option for CHF patients with bradycardia.