Evaluation of patients for paroxysmal atrial fibrillation after ischemic stroke.

A n 84-year-old woman with a medical history significant for hypertension and hyperlipidemia presented with aphasia and was found to have a left parietal subacute infarct with hemorrhagic conversion and a remote right parietal lobe infarct, not previously recognized on computed tomography of the head. Workup included a transthoracic echocardiogram that showed normal left ventricular size, an ejection fraction >65%, and abnormal left ventricular diastolic filling. The left atrium was mild to moderately dilated. There was mild mitral regurgitation, mild pulmonary hypertension, and no evidence of patent foramen ovale with agitated saline. She complained of intermittent palpitations (every few weeks) and was placed on telemetry during her inpatient stay, with no significant arrhythmia detected. After her inpatient admission, she was treated with aspirin and had a 30-day event monitor that showed no episodes of atrial fibrillation. One year later, she presented at the office of her primary care physician with complaints of palpitations and shortness of breath. She was found to be in atrial fibrillation and was subsequently treated with warfarin. Atrial fibrillation is a common cause of ischemic stroke; overall, one sixth of cerebral infarcts are attributed to atrial fibrillation. As patients age, that proportion increases. Between 50 and 59 years of age, 1.5% of strokes are attributed to atrial fibrillation, but between 80 and 89 years of age the proportion increases to 23.5%. 1 In patients with rheumatic heart disease, the incidence is even higher, 17× that of patients without atrial fibrillation. 2 Atrial fibrillation can be persistent (lasting >7 days) or paroxysmal (spontaneously terminating in <7 days). Diagnosing paroxysmal atrial fibrillation can be a challenge but an important endeavor in patients suspected of cardioembolic stroke. All patients with prior stroke, transient ischemic attack, or thromboembolism receive at least 2 points on the CHADS 2 (congestive heart failure, hypertension, age, diabetes, stroke) score and CHA 2 DS 2-VASc (CHADS 2 + additional vascular risk factors of vascular disease and female sex) score and are considered high risk for recurrent stroke. There is clear evidence that anticoagulation is the treatment of choice for these patients. 3 Atrial fibrillation is caused by uncoordinated atrial activation , leading to deterioration of mechanical function. The ventricular response depends on the electrophysiological properties of the atrioventricular node and conduction system. Atrial fibrillation is often associated with structural heart disease. Factors correlated with the development of atrial fibrilla-tion include left atrial size, valvular disease …