High Risk Versus Futility in Revascularization of Patients With SIHD
A 65-year-old man with a past medical history of diabetes, hypertension, hyperlipidemia, and coronary artery disease status post bypass grafting in 2012 (left internal mammary artery to first obtuse marginal, right internal mammary artery to left anterior descending coronary artery, saphenous vein graft to right posterior descending artery) presented for routine follow-up with exertional dyspnea and fatigue. He stated that he leaves his apartment on most days and is able to walk up to five blocks prior to stopping to rest. He felt he was able to walk farther a few months ago. He was also less capable of performing his usual activities around the house due to lack of energy. His current medication regimen included aspirin 81 mg daily, atorvastatin 80 mg at bedtime, metoprolol succinate 50 mg daily, and isosorbide mononitrate sustained release 60 mg daily. His vitals were as follows: heart rate 53 bpm, blood pressure 138/77 mmHg, and oxygen saturation 99% on room air. His physical exam was unremarkable. His electrocardiogram (ECG) in clinic showed sinus bradycardia with voltage criteria for left ventricular hypertrophy and a left bundle branch block.
Which of the following is the best initial step in evaluation and management of his symptoms?