Dispersion in ventricular repolarization in the human, canine and porcine heart

The relation between local repolarization and T-wave morphology in heart failure patients

“…The flat to moderately positive TD-TR relations are comparable to those observed in patients with aortic stenosis [4] and in patients with arrhythmias [17]. In contrast, negative TD-TR relations have been reported in relatively normal hearts [1,4,18]. Altogether these data seem to indicate that in healthy hearts the sequence of repolarization is opposite to the sequence of depolarization (negative TD-TR slope) whereas in various kinds of compromised hearts repolarization follows depolarization (slope N 0), albeit that the dispersion of repolarization is generally smaller than that of depolarization (slope b +1).…”

“…The previous studies were mostly limited to the LV [1,4,17,18], or RV [17] alone, whereas in the present study most patients with wide QRS complex were mapped in both ventricles, thus providing a more comprehensive view on repolarization. The first studies in this field used epicardial mapping [1,4,18] but later studies also used endocardial mapping [17,18] showing no significant differences in the TD-TR relation with epicardial mapping.…”

“…This concordance can only be understood if the main direction of repolarization is opposite to that of the preceding depolarization, in other words, that the latest depolarizing regions repolarize first. Indeed, many studies in animals and relatively healthy humans observed an inverse relation between the time of depolarization (TD) and repolarization (TR) of a region [1][2][3]. Less negative or even positive TD-TR relations have been observed in small groups of patients with aortic valve stenosis, coinciding with smaller or discordant T-waves [4,5].…”

Ventricular stimulus site influences dynamic dispersion of repolarization in the intact human heart

“…Dispersion of repolarization is an important factor in the genesis of ventricular arrhythmia (7), especially in cases of functional reentry. Although regional dispersion of repolarization alone is not sufficient to establish a reentrant circuit (12, 38), it is a recognized substrate for the development of reentry (8). This raises questions as to whether epicardial ectopy may be more arrhythmogenic than ectopy from endocardial sites.…”

Mechanisms linking electrical alternans and clinical ventricular arrhythmia in human heart failure

“…For example, spatial repolarization patterns vary between human hearts 19 , where patients with large spatial repolarization gradients may be more prone to arrhythmogenic RT-ALT. Thus, electrical alternans pacing protocols may have significantly different results depending on pre-existing repolarization gradients.…”