Abstract 18768: Diagnosis of Occult Atrial Fibrillation in Patients With Embolic Stroke of an Undetermined Source Based on Left Atrial Strain

Introduction and Hypothesis: A late electrocardiographic evaluation of patients with embolic stroke of an undetermined source (ESUS) can show atrial fibrillation as a potential cause of embolic stroke. Existing literature has highlighted that left atrial dysfunction can lead to the development of paroxysmal atrial fibrillation (PAF) and subsequent embolism. Our study sought to evaluate the diagnosis of occult atrial fibrillation in patients with embolic stroke of an undetermined source based on abnormalities in the left atrial strain.

Methods: 230 patients were included in our multi-center, observational study with the mean age as 56.4 years and 26% females. We followed up on these patients for the occurrence of paroxysmal atrial fibrillation and recurrent ischemic stroke. Trans thoracic echocardiography (TTE) was done, and images were subsequently analyzed for spackle tracing deformation patterns. Primary and secondary outcomes included plotting these atrial strain values against PAF and recurrent ischemia, respectively.

Results: 198 patients completed the study. Patients with newly diagnosed PAF had more abnormal left atrial reservoir strain (LASr; 27.3% ± 12.2%, P<0.05) and left atrial conduit strain (LAScd; -13.7% ± 6.2%, P<0.05) compared with patients who had normal rhythm. Multivariable logistic regression analysis showed that LAScd was associated with occult PAF (adjusted odds ratio [aOR] = 1.212, 95% CI, 1.043-1.314, P<0.05) and the composite outcome of AF and recurrent ischemic stroke (OR = 1.146, 95% CI, 1.023-1.185, P<0.05).

Conclusions: Our study concluded that abnormal left atrial strain is associated with the detection of occult AF in patients admitted with embolic stroke of undetermined origin. Early detection of etiology by determining left atrial strain can lead to better prognosis and good clinical outcomes.