Are there any specific treatments for heart diseases relating to sinus bradycardia?

Depends: It depends on the cause and if there are any symptoms from the bradycardia. Many athletes have a resting bradycardia. This reflects their excellent conditioning and requires no treatment. In other cases a slow heart rate can be seen with hypothyroidism which is treated by adding thyroid meds. Others may have a slow heart rate indicating a conduction system abnormality and require a pacemaker.

I think NOT: Many options... A] discontinuing the medications, thats causing it b] treat underlying diseases...[hypothyroidism/adrenal dysfunction....] c] make sure there is no underlying coronary artery disease d be active and exercise daily...[aerobic] e] finally, may need a "pacemaker".