A Prolonged Atrial Electromechanical Interval is Associated with a Stroke in Patients with Paroxysmal Atrial Fibrillation

Introduction: Paroxysmal Atrial Fibrillation (PAF) is associated with an increased risk of an embolic stroke. The atrial electromechanical interval (PA-PDI) determined by the transthoracic echocardiogram reflects the total atrial electrical activation time and is associated with the CHADS2 score. This study aimed to evaluate whether the PA-PDI interval was useful in identifying patients at risk of a stroke. Hypothesis: PA-PDI interval is useful in identifying patients at risk of a stroke. Methods: A total of 148 patients (75% male, mean age 66±11 years) with PAF who underwent catheter ablation at our hospital from April 2011 to April 2014 were enrolled in this study. The PA-PDI interval was determined as the time interval from the initiation of the P wave deflection to the peak of the mitral flow A wave on pulse wave Doppler imaging. A logistic regression analysis was used for a multivariate analysis to identify the factors associated with a history of a stroke. Factors such as an age≧75, hypertension, diabetes mellitus, congestive heart failure, and structural heart disease were included in the model. Results: Fourteen patients had histories of strokes. Patients with strokes had a longer PA-PDI interval compared to those without (168±16ms vs. 153±23ms, P=0.006). In the univariate analysis, a history of a stroke was associated with a prolonged PA-PDI interval (P=0.03) and structural heart disease (P=0.03). In the multivariate analysis, only the PA-PDI interval was associated with a history of a stroke. At a cutoff point of 150ms identified by an ROC curve, the positive and negative predictive values of the PA-PDI interval for a history of a stroke were 13.4% and 98.0%, respectively. Conclusions: Our results suggested that the PA-PDI was a useful tool to identify patients with high risk of a stroke.