A 70-year-old man with a history of chronic obstructive pulmonary disease (COPD), treated with inhalers, presents to his pulmonologist with worsening shortness of breath which he thinks is related to COPD. He has noted intermittent palpitations. His physician checks his blood pressure, which is 100/70 mm Hg, and notes a rapid heart rate, prompting an ECG.
Figure 1. Courtesy of Philip J. Podrid, MD.