My Father Who Is 91 Has Been Having Great Difficulty

My father who is 91 has been having great difficulty in keeping his blood pressure stabile. He experiences fainting, dizziness and has fallen and pulling a chip off of his hip 2 years ago. Today he was laying in the sun and became unresponsive. My mother called 911 and my brother did some car until he came to. Para medics took him to the hospital. Test were run, IV fluids administered. They released him and he is resting at home. This is about the fourth time for this type of episode. He is seeing a new doctor and has been seen by a cardiologist. They have been trying to adjust his blood pressure melds for the last 4 months. My question is does a heart rhythm problem cause blood pressure spikes and drops and would a pacemaker solve the pressure problem.