Association between electrocardiographic and echocardiographic atrial abnormalities and prognosis in cryptogenic stroke

Abstract

Background and purpose: The role of atrial fibrillation in cryptogenic stroke (CS) is well known. However, the usefulness of left atrial (LA) electrical and morphological abnormalities to identify more disabling strokes in sinus rhythm patients is less studied. We evaluated the association between electrocardiographic P-wave abnormalities and echocardiographic LA measures with neurological disability in patients with cryptogenic stroke.

Methods: In a retrospective cohort, we included all consecutive hospitalized patients with cryptogenic stroke. Patients were classified according to modified Rankin scale at hospital discharge and at 3 months. LA abnormalities were identified by electrocardiographic (ECG) P-wave, axis and LA enlargement criteria, and by bidimensional echocardiograph through left atrial diameter and volume index.

Results: Among the 143 patients with CS (63.4 ± 14.2 years, 53% women), 70 patients were classified as non-disabling stroke (Rankin score < 2) and 73 patients as disabling stroke (Rankin score ≥ 2) at hospital discharge. On echocardiogram, more patients with disabling stroke presented with enlarged LA volume index (48% vs. 25%; p = 0.01). This difference remained significant after adjustment for age, gender, CHA₂DS₂-VASc and NIHSS scores (p = 0.02) and even when the LA volume index was analyzed as a continuous variable (p = 0.055). Also, enlarged LA volume index was more prevalent (52% vs. 25%; p = 0.03) among those with disabling stroke at 3 months after hospital discharge. Among ECG criteria, only the LA enlargement assessed by downward deflection was more prevalent in disabling stroke.

Conclusion: Our study demonstrated an association between left atrial enlargement, assessed by downward deflection from ECG and volume index from echocardiogram, and more disabling cryptogenic strokes. This information could help to identify patients with poorer prognosis, or a subgroup where atrial cardiopathy may play a role in cardioembolic pathway.

Keywords: Cryptogenic stroke; Echocardiography; Electrocardiography; Left atrium.