Abnormal P-Wave Axis and Ischemic Stroke: The ARIC Study (Atherosclerosis Risk In Communities)

Area of Science:

• Cardiology
• Neurology
• Electrocardiography

Background:

• Abnormal P-wave axis (aPWA) is associated with atrial fibrillation and mortality.
• The relationship between aPWA and ischemic stroke risk has not been previously reported.

Purpose of the Study:

• To investigate the association between aPWA and incident ischemic stroke.
• To determine if aPWA is an independent risk factor for stroke, even in the absence of atrial fibrillation.

Main Methods:

• Analysis of 15,102 participants from the Atherosclerosis Risk In Communities (ARIC) study.
• Definition of aPWA using 12-lead ECGs (values outside 0 to 75°).
• Incident ischemic stroke cases identified via computer algorithm and physician review, analyzed using multivariable Cox regression.

Main Results:

• A significant association was found between aPWA and a 1.50-fold increased risk of ischemic stroke.
• The association was stronger for cardioembolic stroke (2.04-fold increased risk) and also observed for thrombotic stroke (1.32-fold increased risk).
• These associations remained significant even after adjusting for atrial fibrillation and other stroke risk factors.

Conclusions:

• Abnormal P-wave axis is an independent predictor of ischemic stroke.
• The findings suggest that altered atrial electrical activation may predispose individuals to cardiac thromboembolism, independent of diagnosed atrial fibrillation.