Background: Cardioembolism is the cause of cerebral infarct in 15 to 30% of cases. The aim of the present work is to detect, by transesophageal echocardiography (TEE), potential cardioembolic sources in patients with cerebral ischemia without atherosclerotic carotid disease at duplex carotid ultrasound examination.
Methods: From 1991 onwards, 420 consecutive patients who presented with cerebral ischemia, detected by computerized axial tomography, underwent an echotomography examination of the cerebral afferent vessels and a transthoracic echocardiogram (TTE). Three hundred and thirty out of these patients were excluded since they had carotid plaques; of the remaining 90, 80 (mean age 61.6 years range: 25-86, 50 males and 30 females) underwent a transesophageal examination. The patients were studied with an HP Sonos 1000 system with 2.5 and 3.5 MHz frequency probes for TTE; 7.5 and 5 MHz probes were used for echotomography and TEE respectively.
Results: The TEE identified cardioembolic sources in 81% of the cases, versus 46.2% using TTE (p < 0.0001) with a significant statistical difference for thrombus, spontaneous echo contrast and paradoxic shunt (p < 0.0001). When the patients with cerebral ischemic events (group A) were compared with the 156 cardiac patients (group B) (mean age: 59.7, range: 19-86, 92 males and 64 females), without ischemic events, group A showed a significant higher prevalence of thrombus, spontaneous echo contrast, calcification of the mitral anulus, interatrial aneurysm and paradoxic shunt.
Conclusions: Our experience confirms that TEE is very useful and more sensitive than TTE for diagnosing cardioembolic sources; so, this new diagnostic tool should become a useful part of the diagnostic iter for patients with ischemic stroke and normal carotid vessels. The prevalence of some heart conditions in the stroke group poses the problem of whether to advise anticoagulant or antiplatelet therapy and, in selected cases, a surgical approach. The absence of heart and vascular conditions in the extracranial regions of patients who have had a cerebral stroke, suggests an intracranial condition and the problem of performing an angiographic examination arises.