Indexing repetitive to single ventricular premature complexes: A new concept in acute drug testing

The clinical application of acute drug testing for the treatment of ventricular arrhythmias is limited by epidemiologic, statistical and therapeutic uncertainties. The suppression of ventricular premature complexes (VPCs) is confounded by statistical analyses that require high-grade suppression simply to confirm a true response^1,2 and by the lack of clinical evidence of efficacy with respect to mortality.³ Repetitive forms of VPCs are generally considered more important than single VPCs,⁴ and improved clinical outcome has been associated with the high-grade suppression of repetitive forms in selected high-risk subgroups.⁵ However, the spontaneous variability of repetitive forms is frequently even more marked than single VPCs, rendering statistical analysis nearly impossible.⁶ Although these uncertainties have directed attention to the suppression of sustained and nonsustained ventricular tachycardia, both in drug development and therapies, there remains a clinical need to test acutely the efficacy of antiarrhythmic drugs against manifest ventricular arrhythmias. We report a new approach to this evaluation.