XDH and congestive heart failure: According to recent reports increased production of serum uric acid through activation of xanthine oxidase (XO) from xanthine and hypoxanthine was found in the patients of chronic heart failure (CHF).5 XO also generates free radicals including reactive oxygen species (ROS) which may participate in oxidative damage in the myocardium.6 However, ROS also play a crucial role during cardiomyocytes apoptosis.7 In addition, inadequate ROS levels were also found in human cardiac valve dysfunction during apoptosis.