In heart failure management, what is a safety concern regarding beta-blocker use?

The concern regarding the use of beta-blockers in heart failure management relates to their effect on heart rate. Beta-blockers can lower heart rate, which is beneficial in cases of tachycardia, but if the heart rate drops too low—specifically to a pulse under 50 beats per minute—this can lead to bradycardia. Bradycardia can result in inadequate cardiac output and may exacerbate heart failure or lead to detrimental symptoms such as dizziness or syncope. Therefore, monitoring the pulse rate is critical, and initiating or continuing beta-blocker therapy should be approached with caution when the resting heart rate is below this threshold.

While other concerns exist, such as the potential for development of peripheral edema or considerations related to renal function, the most immediate and directly related safety concern for heart failure patients starting or continuing beta-blockers is the risk associated with a low pulse rate.