Study Overview: This study is testing a new way to use a pacemaker to help control blood pressure. A pacemaker is a small device put in the chest to help the heart beat regularly. The special method being tested is called atrioventricular interval modulation (AVIM), which is a technique that adjusts how the heart's upper and lower chambers communicate. The study uses Medtronic Astra/Azure pacemakers that are already in place.

The study lasts for three years. It starts with a screening phase, then a one-year phase where neither the doctors nor patients know who gets the special treatment, and finally a two-year phase where everyone knows what treatment they receive. Only people who got their pacemaker within the last 90 days and have high blood pressure that isn't well controlled can join.

• The study lasts for three years with different phases.
• You need a Medtronic Astra/Azure pacemaker implanted recently to join.
• You will receive standard care or the new method during the study.