Heart rate variability in patients with thalassemia major.

Cardiac dysfunction, including congestive heart failure and fatal arrhythmia, is a frequent cause of death among children with thalassemia major (TM). Autonomic nervous system activity typically is measured by a series of cardiovascular autonomic function tests, but these tests are unsuitable for young patients because they are invasive or complex. Heart rate variability assessment is a technique that measures the beat-to-beat variability in R-R intervals. This variability reflects changes in autonomic activity and their impact on cardiovascular function. This study examined 32 patients with TM to evaluate heart rate variability (HRV) in a preclinical phase of cardiac involvement. The study patients showed no evidence of heart failure or signs of peripheral or autonomic neuropathy. All HRV parameters were significantly reduced in the TM patient group compared with the control group. The results of this study can be interpreted as evidence of early cardiac autonomic neuropathy in young thalassemic patients. Therefore, all TM patients should be screened using HRV analysis for that complication.