A 67-year-old man with a 30 pack-year history of cigarette smoking, who has hypertension, diabetes, and mild chronic obstructive pulmonary disease presents to the emergency department with left-sided hemiparesis and sensory loss for the past 6 hours.

Physical examination performed in the emergency department reveals a regular heart rhythm with otherwise normal heart sounds. Lungs are clear to auscultation, but left-sided weakness and sensory loss is noted. Lower extremity examination shows trace ankle edema.

Significant laboratory results included a normal brain natriuretic protein level, elevated cardiac troponin level, and no evidence of metabolic disturbance. 

An electrocardiogram is ordered and reveals sinus rhythm with deep lateral T-wave inversions. Computed tomography scan of the brain shows a small acute infarct in the territory of the right middle cerebral artery with no evidence of hemorrhage. He is treated with thrombolytics and started on aspirin prior to hospital discharge.

What would be the next best step in the diagnostic workup for this patient?

A. Transthoracic echocardiography to evaluate for thrombus or patent foramen ovale

B. Transesophageal echocardiography to evaluate for thrombus or patent foramen ovale

C. Exercise nuclear myocardial perfusion imaging  

D. 24-hour telemetry monitoring followed by 10-day Holter monitoring to evaluate for episodes of atrial fibrillation

E. Cardiac catheterization because of the elevated troponin level and deep T-wave inversions