What Is the Rhythm?

Published:October 31, 2022DOI:
      An 88-year-old white man presented to our hospital for a regadenoson stress test. He had a history of coronary artery disease and had stents placed in both the left anterior descending and the left circumflex arteries 7 years earlier. He was taking metoprolol succinate 25 mg/day. He was not taking digoxin or any antiarrhythmic drugs. A recent echocardiogram showed normal left ventricular systolic function and mild aortic stenosis. The nursing staff noticed severe bradycardia. Blood pressure was normal, and the patient was asymptomatic. Heart block was suspected on baseline electrocardiogram (ECG) (Figure 1). The patient told the staff that he had declined placement of a permanent pacemaker in the past. He had no history of syncope or dizziness. The patient's cardiologist was contacted. The stress test was canceled, and the patient was sent to the emergency room for evaluation and management. A repeat ECG (Figure 2) was obtained.
      Figure 1
      Figure 1ECG obtained on presentation.
      Figure 2
      Figure 2ECG obtained in the emergency room 1 hour after presentation.
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