Specific patterns of premature beats tend to initiate ventricular tachyarrhythmias in human patients

Introduction. Previously, we demonstrated that certain patterns of abnormal rapid beats, notably “short-long-short-short” (SLSS) patterns, tend to produce action potential block in computer models, and tend to initiate VF in in vivo canine experiments, consistent with our theory based on electrical restitution. Here we present evidence that these same patterns often precede VF in human ECG recordings. Methods. Thirty-four ECG recordings from just prior to and during tachyarrhythmic events were obtained from ICDs implanted in several human patients. The distributions of the first four abnormal RR intervals prior to arrhythmia onset were fit to single-gaussian and dual-gaussian distributions. Results. Dual-gaussian distributions were obtained for the second and third abnormal beats, while single gaussian distributions were obtained for the first and fourth. These distributions are consistent with the tendency of the SLSS pattern of premature beats, as well as SLLS and SSSS patterns, to precede the tachyarrhythmic event, as described by our computer model. Conclusions. The results provide further evidence that electrical restitution theory, the basis for both our theory and computer model, although imperfect, is sufficient to both predict and understand the manner in which premature beats initiate VF. This understanding may, in the future, lead to new methods for preventing VF, through the imposition of stimuli designed to avoid the dangerous premature beat patterns described in this study.