Background: The importance of cardiogenic embolism as a cause of cerebral ischaemic events may be underestimated if potential cardiac sources of embolism remain undetected. Transoesophageal echocardiography (TOE) is more sensitive in detecting such abnormalities than earlier methods and may result in more frequent recognition of cardiogenic embolism.
Aims: To establish in an unselected stroke population the prevalence of potential cardiac sources of embolism detectable on TOE and their relationship to atrial fibrillation and carotid stenosis.
Methods: One hundred and thirty-five consecutive patients with cerebral ischaemic events were studied using transthoracic and monoplane transoesophageal contrast echocardiography and carotid Duplex imaging or cerebral angiography.
Results: Thirty patients (22%) had atrial fibrillation. In 43 patients (32%), no cardiac source of embolism was identified; in eight echocardiography was normal. At least one potential cardiac source of embolism was identified in 92 patients (68%) with multiple findings in 41; these patients were older (70 +/- 9 years vs 61 +/- 14 years; p = 0.0001), more frequently in atrial fibrillation (28/92 vs 2/43; p = 0.0017) and more frequently had cortical or large subcortical stroke (71/92 vs 23/43; p = 0.005). Carotid stenoses were detected in 55% of patients, not significantly different in those with and without cardiac abnormalities.
Conclusion: When bias in selection of patients is avoided, TOE detects a potential cardiac source of embolism in most patients with cerebral ischaemia, particularly those older and in atrial fibrillation. Multiple cardiac abnormalities and coexistent carotid disease are common. The implication of these findings for prevention of stroke awaits age-matched controlled studies.