A 74-year-old woman with dyslipidemia presented to the emergency department after 3 days of shortness of breath, generalized weakness, and light-headedness without syncope. She was found to have pulmonary vascular congestion, mild hypoxia, and bradycardia. Her blood pressure was 125/80 mm Hg, and her heart rate was regular at 44 beats per minute (bpm). An electrocardiogram (ECG) was obtained (Figure 1).