IMO, and I could be wrong, but the drive from Minn/St Paul, other than the Mall of America in Minneapolis, has nothing of interest until you get to the Badlands, Custer STate Park, Crazy HOrse, Mt Rushmore area. Deadwood SD for a day and night, I found to be of interest.
Sinoatrial node is located at the junction of the superior vena cava with the right atrium.
While the sinoatrial node typically regulates the heartbeat during normal sinus rhythm, PACs occur when another region of the atria depolarizes before the sinoatrial node and thus triggers a premature heartbeat.