Premature ventricular contractions originating from the right ventricular outflow tract: three-dimensional distribution of the target sites and their electrocardiographic characteristics.
ABSTRACT 1. The purpose of the present study was to explore the relationship between electrocardiogram (ECG) patterns of right ventricular outflow tract (RVOT) premature ventricular contractions and the three-dimensional distribution of the target sites. 2. Thirty-three consecutive patients were included in the study. The target sites were identified by non-contact mapping and confirmed by successful ablation. The distribution of the target sites in the three-dimensional reconstructed geometry of the RVOT was classified in three directions: (i) anterior (A)/posterior (P); (ii) free wall (F)/septal (Se); and (iii) superior (Su)/inferior (I). The ECG characteristics were then analysed according to the three-dimensional distribution of the target sites. 3. The following indices were helpful to identify the position of the target site: (i) QRS duration (> or = 150 msec = F; < 150 msec = Se; P < 0.05); (ii) the R wave pattern in the inferior leads (RR' or Rr' = F; R = Se; P < 0.05); (iii) the R wave amplitude in the inferior leads (high = Se; low = F; P < 0.05); (iv) the initial r wave width in lead V(1) (wide = F; narrow = Se; P < 0.05); (v) the QS wave amplitude in aVR and aVL (if aVR < aVL, A; if aVR > or = aVL, P; P < 0.05); and (vi) the initial r wave amplitude in lead V(1) and V(2) (if V(1) > or = 0.15 mV and V(2) > or = 0.3 mV, Su; if V(1) < 0.15 mV or V(2) < 0.3 mV, I; P < 0.05). 4. In conclusion, the ECG characteristics were associated with target site locations in all three directions.
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ABSTRACT: We present an approach that links nonlinear model reduction techniques with control vector parametrization-based schemes to efficiently solve dynamic constraint optimization problems arising in the context of spatially-distributed processes governed by highly-dissipative nonlinear partial differential equations (PDEs). The proposed approach is applied to a metal-organic vapor-phase epitaxy process for the production of GaN thin films, with the objective to minimize the spatial non-uniformity of the deposited film across the substrate surface.American Control Conference, 2004. Proceedings of the 2004;
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ABSTRACT: In this contribution we investigate the influence of the doping element on the contact formation to p+-type Si. Contacting B doped layers with Ag thick film paste leads to very few Ag crystallites at the contact interface and results in poor contact resistances [1–3]. Using Ag/Al thick film paste for contact formation, the contact is not only formed by Ag crystallites, but by diversely shaped Ag/Al contact spots and the contact resistance is reduced by more than one order of magnitude . Al melting at the Si wafer surface forms Al doped rectangles on the Si wafer where the growth of Ag/Al/Pb spikes is enhanced.When contacting Al doped layers with Ag thick film paste a larger number of Ag crystallites is observed than for B doped layers. If the contact is formed with Ag/Al paste the number of Al-rich rectangles is enhanced and we detect higher doped areas under the contact spots. The contacts detected have an ellipsoidal, pyramidal or “L-formed” shape. We conclude that not only the acceptor impurity concentration under the contact area is crucial for the contact formation, but also the properties of the specific acceptor present.Energy Procedia 01/2011; 8:533-539.