Hello. Thank you for asking on HCM. I understand your concerns. The pacemaker is mostly placed in cases where the electrical impulse cannot be generated and/or conducted by the heart s specialized structures to do so. It works in the way that it is stimulated any time that heart structures fail to do so. I suppose that calcium channel blockers which you are taking to controll your hypertension are from the fraction that do not act on atrioventricular (AV) node (the dipins ). Even if they are from the group that strongly inhibit conduction in the AV node (verapamil, diltiazem), it does not matter, because the implanted pacemaker would act by producing a beat. My opinion is that you should consult the doctor who periodically controls the functioning of your pacemaker. If you remain on AV block, after havin a dual-chamber pacemaker implantation, the highest probability is that it is not functioning properly (end-of-life battery, lead dislodgment, pacemaker dislodgment in the subclavian pocket, etc.) I hope I was helpful. Take care.