Suppressed left atrial function in PAF

Abstract

We thank Dr Li and his colleagues for their correspondence and for highlighting the differences between our published study in IJC [ [1] Henein M. Zhao Y. Henein M.Y. Lindqvist P. Disturbed left atrial mechanical function in paroxysmal atrial fibrillation: a speckle tracking study. Int J Cardiol. Mar 12 2012; 155: 437-441 Google Scholar ] and theirs [ [2] Li et al. Two-dimensional speckle tracking echocardiography: a novel approach to evaluate left atrial mechanical function. Int J Cardiol. Mar 22 2012; 155: 481-482 Google Scholar ]. Our study aimed at assessing left atrial contractile function using speckle tracking echocardiography in a group of paroxysmal atrial fibrillation (PAF) patients over a month after the last episode. The results showed clear evidence for reduced left atrial systolic function as shown by strain and strain rate measurements of the whole cavity mainly involving as well the lateral wall. These findings are in agreement with Dr Li's results in a similar group of PAF patients (as stated in his letter). Despite their study being unpublished and therefore difficult to compare the main difference between the two studies was our control group which consisted of healthy age and gender matched subjects with no risk factors compared to hypertensives with no PAF in Dr Li's study. An additional interesting finding was the time to peak longitudinal strain which was delayed in Dr Li's patients. Although we did not measure this time interval, such finding concurs with our previously published work where we found atrial electromechanical delay, measured from M-mode recordings of the atrial function, significantly prolonged in patients prone to atrial arrhythmia [ 3 Li W. Xiao H.B. Henein M.Y. Somerville J. Gibson D.G. Progressive ECG changes before the onset of atrial flutter in adult congenital heart disease patients. Heart. Jun 2001; 85: 703 Google Scholar , 4 Li W. Somerville J. Gibson D.G. Henein M.Y. Disturbed atrioventricular electromechanical function long after Mustard operation for transposition of great arteries: a potential contributing factor to atrial flutter. J Am Soc Echocardiogr. Nov 2001; 14: 1088-1093 Google Scholar ]. Furthermore, using STE with its limited frame rate (commonly less than 100 f/s) limits the accuracy of time interval measurements.