Abstract
Introduction
Around 25% of all ischaemic strokes have no known cause despite standard investigations. Most of these cases are suspected to have an embolic source for ischaemia, leading to the moniker of Embolic Stroke of Undetermined Source (ESUS). Recent studies suggest that abnormalities of the left atrium, in the form of atrial cardiopathy, can lead to increased risk of stroke even in the absence of atrial fibrillation (AF), which may be either as precursors to AF or as independent risk factors for the development of left atrial thrombus and subsequent stroke.
Purpose
The aim of this study was to measure LA electromechanical dissociation, LA volumes and P-wave dispersion as markers of atrial cardiopathy in patients with ESUS to determine whether atrial cardiopathy may be in the causal pathway of ESUS.
Methods
28 patients presenting with ischaemic stroke and fulfilling the criteria for ESUS were enrolled into this cross-sectional, observational study. All patients had 24-hour Holter monitoring done to rule out the presence of AF. The control group consisted of 28 age- and gender-matched apparently healthy individuals. On ECG, P-wave Dispersion (PWD) was calculated by subtracting minimum P-wave duration from maximum P-wave duration. On echocardiography, time intervals from the beginning of P-wave to beginning of A' wave from the lateral mitral annulus in tissue doppler imaging was measured as the atrial electromechanical delay. LA volumes were recorded using the Modified Biplane Simpson's method. Statistical analysis was performed using student's t-test, chi-square test, and Pearson's test.
Results
Baseline demographic and laboratory characteristics were similar between the two groups. Increased PWD (34.14±9.89 ms vs. 27.32±8.95 ms; p=0.01), atrial electromechanical delay (73.32±16.31 ms vs. 63.63±13.59 ms; p=0.02) and LA volumes were observed in patients with ESUS as compared to controls. A significant correlation was also found between these parameters (p<0.01).
Discussion
According to the results of our study, PWD, atrial electromechanical delay and LA volumes may be novel predictors for ESUS. Atrial cardiopathy is a unique mechanism of thrombo-embolism in ESUS patients and our data establishes its association with ESUS. Further studies will be needed to shed more light on its role in the causality of stroke in the ESUS population.
Measurement of electromechanical delay
Funding Acknowledgement
Type of funding source: None
Forge AHEAD with stricter criteria in future trials of embolic stroke of undetermined source
