Cilnidipine is a blood pressure medication that generally does not directly slow down the heart's electrical conduction, unlike some other heart drugs. However, because you have a right bundle branch block and an irregular heartbeat, it is very important to consult your cardiologist before taking it. Any changes in blood pressure can gently affect how your heart beats. Your doctor can perform a quick check to ensure this medication is perfectly safe and tailored for your specific heart rhythm. Please rest assured.