Evaluation of effects of antiarrhythmics on ventricular premature contraction

Although subjective symptoms and brief recording of ECG have been used for an efficacy evaluation of new antiarrhythmics on ventricular premature contraction (VPC), incidence of subjective complaints in VPC was under 25% and number of VPC for 3 min did not correlate enough to those for 24 hours, indicating these parameters are not appropriate for such a trial. Number of VPC automatically counted by DECG (continuous ECG recording for 24 hours) showed high accuracy, while day to day variation of VPC arose as the next problem. While cases of more than about 7,000/day showed very little day to day variation, cases of less than about 1,000/day had poor reproducibility, indicating that the former group can be used for the trials of new antiarrhythmics, but not the latter group. For cases with medium magnitude of VPC variation, DECG should be recorded twice during the period without drug administration and application of the paired t-test for number of VPC in each corresponding hour may bring a good evaluation.