Embolic Stroke Diagnosed by Elevated D-Dimer in a Patient With Negative TEE for Cardioembolic Source

Abstract

We report a case of cerebrovascular accident with thromboembolic stroke etiology in a patient who had atrial flutter and negative transesophageal echocardiography (TEE) results. The increased D-dimer levels (1877 ng/mL) initiated referral for magnetic resonance imaging and magnetic resonance angiography of the brain that showed classic recanalization of an embolic thrombus in the angular branch of the left middle cerebral distribution. The D-dimer level of this patient was normalized after 3 months of anticoagulation therapy. Although TEE is considered the gold standard for evaluation of cardiac source of embolism, exclusion of intracardiac thrombus with TEE alone does not eliminate the risk of thromboembolic events. This case highlights the utility of D-dimer as a potential adjunct in the decision-making process to guide investigation of thromboembolism, determine subsequent therapy, and hence reduce the risk of embolic stroke recurrence.

Keywords: D-dimer; atrial thrombosis; stroke; transesophageal echocardiography.

Figure 1.

(A) CT head without contrast found no evidence of acute intracranial process such as thrombus, hemorrhage, mass effect, or hydrocephalus. (B, C) TEE images showed no evidence of thrombus in the left atrial appendage nor valvular vegetations. It showed a normal left ventricular function with ejection fraction of greater than 55% and secondum ASD (8.2 mm size with qp:qs ratio of 1.6:1).

Figure 2.

(A) Brain MRI showed a small acute left motor cortex infarct with spotty subcortical white matter ischemic lesions. The lesion in the left precentral gyrus correlated with the history of right upper extremity weakness. (B) MRA suggested the presence of an embolic stroke by identifying irregular segmental narrowing of the angular branch of the left middle cerebral artery, of concern for recanalization stenosis with either spontaneous fragmentation or lysed thrombus fragmentation.