Does calcium channel blockers lower heart rate
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
The Impact of Calcium Channel Blockers on Heart Rate
Introduction to Calcium Channel Blockers and Heart Rate
Calcium channel blockers (CCBs) are a class of medications commonly used to manage hypertension and various cardiovascular conditions. They function by inhibiting the influx of calcium ions into cardiac and smooth muscle cells, which leads to vasodilation and reduced cardiac contractility. This article explores whether CCBs have a significant effect on lowering heart rate, drawing on insights from multiple research studies.
Effect of Calcium Channel Blockers on Heart Rate in Hypertension
Several studies have investigated the impact of CCBs on heart rate in patients with hypertension. A systematic review and meta-analysis found that CCBs effectively lower blood pressure in both sexes, with a more pronounced effect in females. Specifically, the study noted a decrease in heart rate by 1.8 beats per minute (bpm) in females, while no significant change was observed in males. This suggests that CCBs may have a modest heart rate-lowering effect, particularly in female patients.
Comparison with Beta-Blockers in Atrial Fibrillation
In patients with atrial fibrillation (AF), the effectiveness of CCBs in controlling heart rate has been compared to that of beta-blockers. Data from the AFFIRM trial indicated that both non-dihydropyridine CCBs and beta-blockers were equally effective in achieving a resting heart rate of less than 110 bpm during AF episodes. However, CCBs were associated with a lower incidence of bradycardia during sinus rhythm compared to beta-blockers . This finding highlights that while both drug classes are effective for rate control in AF, CCBs may offer an advantage in reducing the risk of bradycardia.
Efficacy in Permanent Atrial Fibrillation
A study comparing the effects of different rate-reducing drugs in patients with permanent AF found that diltiazem, a non-dihydropyridine CCB, was the most effective in reducing the 24-hour mean heart rate compared to other drugs, including beta-blockers. Diltiazem significantly lowered the heart rate and reduced arrhythmia-related symptoms more effectively than verapamil, metoprolol, and carvedilol. This suggests that certain CCBs, particularly diltiazem, may be superior in managing heart rate in patients with permanent AF.
Combination Therapy and Heart Rate
The combination of CCBs with beta-blockers has been explored for managing chronic stable angina and other cardiovascular conditions. Studies have shown that while this combination can lead to a further reduction in heart rate and blood pressure, it also carries a risk of additive adverse cardiac effects, such as bradycardia and increased cardiac filling pressures. Therefore, while combination therapy can be beneficial, it requires careful patient selection and monitoring.
Conclusion
In summary, calcium channel blockers can lower heart rate, particularly in female patients with hypertension and in patients with atrial fibrillation. Non-dihydropyridine CCBs like diltiazem are particularly effective in reducing heart rate in patients with permanent AF. However, the use of CCBs, especially in combination with beta-blockers, should be approached with caution due to the potential for adverse cardiac effects. Further research is needed to optimize the use of CCBs in various patient populations and to fully understand their impact on heart rate.
Sources and full results
Most relevant research papers on this topic