LAUSR

We have read the clinical research article by Y.S. Chen et al. with great interest, wherein the authors have described about atrial and ventricular response to treatment of premature ventricular complexes (PVC). 1 Chen et al. suggested that PVC therapy effectively reduced ventricular arrhythmic burden. This may prevent left atrium dilation and impaired cardiac function. We agree with the authors regarding the important roles of PVC treatment. However, we have some reservations about the potential detrimental effect from atrial arrhythmia. Simultaneously, we would like to discuss some additional prognostic factors, guiding us whether the PVC therapy is indicated or not. In this study, there was a statistically significant difference in atrial burden between observation and treatment group, and atrial burden in observation group is higher than that in the treatment group (Table 1). Previous studies have reported that increased atrial burden was associated with decrease in left ventricle ejection fraction. 2,3 Moreover, atrial burden was also associated with the risk of atrial fibrillation (AF) and left atrium dilatation. 4 Treatment of PVCs may prevent some cardiomyopathies and left ventricle dysfunction. However, the changes of left atrium and left ventricle ejection fraction can also be caused by underlying frequent atrial burden in patients without treatment. For assessment of left atrium enlargement, it may be unreliable and inaccurate to measure the linear dimension of left atrium, because the left atrium is not only three-dimensional structure with symmetric shape. The enlargement of the left atrium may not occur in a uniform manner. One-dimensional assessment is not sensitive to evaluate the change of left atrial size. Measurement of left atrial volume by two-dimensional or three-dimensional echocardiography can evaluate the change of left atrial size more accurately, and the result are more quantitatively reproducible. 5