الفهرس 
Atrial functional anatomyOnly 14 pages are availabe for public view
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Abstract
Left atrial (LA) enlargement by 2-dimensional (2-D) echocardiography predicts adverse cardiovascular outcomes. Electrocardiographic (ECG) criteria for LA enlargement are based on M-mode echocardiographic LA diameter, which is inferior to 2-D–derived LA volumes.
This study compared established ECG criteria for LA enlargement with atrial volume obtained by 2-D echocardiography to determine if traditional ECG criteria accurately represent LA chamber enlargement, therefore offering a low-cost screening tool.
Our study included thirty patients selected randomly from adult patients underwent transthoracic echocardiographic study for any indication at cardiology department Ain Shams university hospital (Demerdash).
For every patient the following has been done:
Complete history taking. Clinical evaluation includes; General examination with special regard to blood pressure, pulse, weight and height. Standard resting 12-lead electrocardiogram was performed for all patients using one channel fukuda denshi device. All patients under went Transthoracic echocardiographic study using (Vivid 5, GE Vingmed) echocardiographic machine Using 2.5-MHz, phased-array probe. Electrocardiograms were assessed manually with calipers by another operator rather than who did echocardiography, measuring leading edge to leading edge. Echocardiography was measured by Simpson’s method of discs, from the apical 4 chamber view with enlargement defined as 32 ml/m2.
We found that P-wave duration ≥110 seconds in limb leads I, II and III showed good correlation between ECG finding of left atrial enlargement &left atrial volume derived by 2 D echocardiography from the apical 4 chamber view (r 0.441&p-value0.015)
There was a significant linear relationship between the indexed left atrial volume and p wave duration ≥110 seconds with sensitivity 77.3%, specifity 75% and accuracy 81%.
Other ECG signs for LA enlargement correlate poorly with 2-D echocardiographic volume which showed non significant relation between negative terminal P wave in v1>40ms and LA max. volume indexed >32ml ( p value 0.271). with sensitivity 27.27% and specifity87.5% and accuracy 43.33%.
also showed a non significant relation between Biphasic P wave in v1>40ms& LA max. volume indexed (>32)with sensitivity 13.64 %, specifity 100 %&accuracy 36.67%.
Our study demonstrates that, of the previously defined ECG criteria for assessing LAE, P-wave duration and in lead II show the best correlation with echocardiographically defined indexed LAV, yet these indicators are rather insensitive. The ECG may therefore be considered a semiquantitative tool in the evaluation of LAE. We found M-mode left atrial dimension and LAV do correlate, and the relationship is linear.
We recommended that more studies are needed to assess the relation of P-wave abnormalities to 2-D LA volume.
Future directions for investigation might include the examination of LAV to P-wave morphology in patients with extremes of LAV (children and lesions causing massive atrial enlargement) and the effect of the atrial geometric axis on p wave morphology.