[Risk factors of cerebral embolism in patients with atrial fibrillation]

Cerebral embolism is one of the major complications of atrial fibrillation (Af). We studied patients with Af, retrospectively, as to the factors related to cerebral embolism. We examined 82 cases with transthoracic echocardiography (TTE) and trans-esophageal echocardiography (TEE) as well as ambulatory (Holter) ECG and 12 leads ECG. Thirty-three patients had cerebral ischemic attack (CIA), including 14 patients with mitral stenosis (MS) and 19 patients with other heart disease or lone Af (NonMS). The CIA group of NonMS were older than other groups. Both the CIA and NonCIA groups had the same frequency of paroxysmal and chronic Af. In the CIA group, there was a tendency of small amplitude of f wave and longer RR interval than the NonCIA group with ambulatory ECG. The CIA group also had larger left atrial cavity size and aortic diameter with TTE. TEE revealed thrombus formation in 29 cases, and the CIA group had a higher occurrence rate of thrombus than NonCIA group. TEE also detected a fuzzy echo in the left atrium in 88% of the CIA group and 42% of the NonCIA group. The risk factors of cerebral embolism could not be made clear in this study, but a fuzzy echo and thrombus in the left atrium with TEE are specific findings of cerebral embolism. Therefore, older patients with paroxysmal Af, large LAD, AOD, small f wave or long RR interval need to be examined by TEE to detect LA thrombus or a fuzzy echo, which are probably major risk factors of cerebral embolism.