Assessment of heart rate variability by using different commercially available systems

We conclude that the results of HRV analysis of the same Holter tape by using different commercially available systems are statistically noncomparable. These findings may be due to different levels of accuracy in removing ectopic beats and artifacts or to different algorithms for HRV analysis. One should keep this in mind when projecting and evaluating clinical trials. Standards for proper assessment of HRV are urgently needed to avoid conflicting data due to different methodological approaches.