Differential Modulation of Electrocardiographic Indices of Ventricular Repolarization Dispersion Depending on the Site of Pacing During Premature Stimulation

Abstract

A differential behavior of the modulation of dispersion of repolarization was found as a function of the site of stimulation.

Role of Dipolar and Nondipolar Components of the T Wave in Determining the T Wave Residuum in an Isolated Rabbit Heart Model

“…We consider this to be an important limitation of the study. Nevertheless, it has been well established by others that with either very close ventricular premature beats 8 or exposure to d‐sotalol doses >10 μM, 17, 18 a significant increase in ventricular repolarization dispersion actually was induced.…”

“…The flow rate of the Langendorff perfusion apparatus was adjusted using a variable‐speed roller pump (Extracorporeal M2102 Infusion Pump) to maintain a perfusion pressure of at least 80 mmHg. The general characteristics of our preparation were described previously 17 . The Tyrode's solution was of the following composition (in mM): 140 NaCl, 5 KCl, 1 MgCl 2 , 0.33 NaH 2 PO 4 , 5 HEPES, 11.1 glucose, and 2.2 CaCl 2 .…”

Quantification of Ventricular Repolarization Dispersion Using Digital Processing of the Surface ECG

“…Later, Arini et al, using an animal heart model with multiple electrode recording system, showed a differential behavior in the modulation of VRD depending on whether premature ventricular stimulation (PVS) were elicited at the right or left ventricle. They concluded that different ventricles anisotropic properties, dissimilar wall thickness and fiber orientation partially contribute to the explanation of results (Arini et al, 2001). More controversial issues came up with Lee et al (see Table 1), and Macfarlane et al who simultaneously showed that QT D calculated from 12-ECG leads derived from the orthogonal XYZ leads (without any regional information) was similar to that obtained from the standard ECG.…”

Evaluation of ventricular repolarization dispersion during acute myocardial ischemia: spatial and temporal ECG indices

“…Fuller et al [17] found in isolated-perfuse canine hearts that induced VrD determined from electrograms was strongly correlated with t-wave width at the electrocardiogram (ECg). By inducing VrD artificially in an in vitro rabbit heart model, we have previously concluded that ECg t-wave widening can result from a combination of apex-base and transmural aPD heterogeneities caused by differential shortening or lengthening of the aPD in some myocardial areas [3][4][5].…”