###Human: What is the reason for fluctuating BP a year after heart attack? ###Assistant: Hello. I would like to explain that the head spinning could be a sign of blood pressure fluctuations. Other possible causes to consider would be an inner ear disorder or low blood flow to the brain (vertebro-basilar insufficiency). For this reason, I would recommend consulting with his attending physician and performing some further tests. A cardiac ultrasound to examine his heart function, a Doppler ultrasound of the carotid and vertebral arteries to examine the blood flow to the brain, thyroid hormone levels, complete blood count for anemia, blood electrolytes, fasting glucose, kidney, and liver function tests. A head-up tilt test is necessary to investigate for orthostatic hypotension.