A short-term course of beta-blocker treatment reduced both resting and exercise heart rate in atrial fibrillation patients, according to a new study investigating the impact on heart rate response during a 6-minute walk test.
The decrease in exercise heart rate was not as pronounced in patients with a lower resting heart rate who did not receive beta-blockers, even though both groups ended up with similar resting heart rates after treatment, according to a study published in Annals of Noninvasive Electrocardiology.
Investigators evaluated 74 atrial fibrillation (AF) patients before and after beta-blocker treatment and included a comparative analysis with 74 age- and sex-matched AF patients not receiving beta-blocker treatment, as well as 74 sinus rhythm patients that were not receiving beta-blocker treatment. The regimen included metoprolol or bisoprolol administered over 3-6 days to achieve a resting heart rate of less than 110 beats per minute.
Treatment significantly reduced both resting heart rate and exercise heart rate in AF patients. However, the treatment did not adequately attenuate the exercise heart rate rise compared to AF patients without beta-blocker treatment, even when resting heart rate levels were similar. Specifically, the increased amplitude was higher in the beta-blocker-treated group (28.2%) compared to the non-beta-blocker group (22%) and sinus rhythm group (6.9%).
The study's limitations included the short treatment duration and the nonrandomization of patients, noted investigators.
They reported no potential conflicts of interest.