Mechanism of heart-rate turbulence

Recently, two post-myocardial-infarction risk predictors were introduced that are superior to all other presently available indicators: turbulence onset (TO) and turbulence slope (TS). These new parameters characterize the behavior of instantaneous heart rate after a ventricular premature beat (VPB), i.e., they describe the reestablishing of heart rate control after an acute perturbation. We propose that the dysfunction of an important cardiovascular control mechanism-the arterial baroreflex-is the mechanism behind these new potent markers. The hypothesis is tested by means of a mathematical model. The results of the model indicates that the recently established risk parameters TO and TS characterize baroreflex function, a known risk stratifier in patients.