<prompt> A 62-year-old male with underlying COPD develops a viral upper respiratory infection and begins taking an over-the-counter decongestant. Sholy thereafter he experiences palpitations and presents to the emergency room, where the given rhythm strip is obtained, demonstrating:Junctional tachycardiaAtrial flutterParoxysmal atrial tachycardiaComplete hea block  <response>: ECG reveals saw tooth waves of atrial flutter with variable AV block. 