A relative of mine has had a BP reading of 250/150 and is concerned about heart. Does anyone know about this?

Seek immediate atten. These levels are severely elevated and will very rapidly lead to kidney failure. They also associated with intracranial bleeds (strokes), heart attacks and aneurysmal ruptures. Get help without delay!
Seek help now. This is an unaccepable blood pressure. The patient should be taken to the er immediately.