Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2015
Digital resolution enhancement of intracardiac excitation maps during atrial fibrillation.
Atrial fibrillation (AF) is often successfully treated by catheter ablation. Those cases of AF that do not readily succumb to ablation therapy would benefit from improved methods for mapping the complex spatial patterns of tissue activation that typify recalcitrant AF. To this end, the purpose of our study was to investigate the use of numerical deconvolution to improve the spatial resolution of activation maps provided by 2-D arrays of intra-cardiac recording electrodes. ⋯ For both the synthetic data and the voltage-sensitive dye maps, we found that deconvolution led to visually improved map resolution for arrays of 10×10 up to 30×30 electrodes placed within a few mm of the atrial surface when the activation patterns included 3-4 features that spanned the recording area. Root mean square error was also reduced by deconvolution. Deconvolution of arrays of intracardiac potentials, preceded by appropriate interpolation and edge processing, leads to potentially useful improvements in map resolution that may allow more effective assessment of the spatiotemporal dynamics of tissue excitation during AF.
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J Clin Monit Comput · Feb 2015
The effects of cardiac output and pulmonary arterial hypertension on volumetric capnography derived-variables during normoxia and hypoxia.
The aim of this study was to test the effect of cardiac output (CO) and pulmonary artery hypertension (PHT) on volumetric capnography (VCap) derived-variables. Nine pigs were mechanically ventilated using fixed ventilatory settings. Two steps of PHT were induced by IV infusion of a thromboxane analogue: PHT25 [mean pulmonary arterial pressure (MPAP) of 25 mmHg] and PHT40 (MPAP of 40 mmHg). ⋯ The elimination of CO2 per breath decreased by 7% in PHT40 and by 12% in COdown but increased only slightly with COup. Dead space variables did not change significantly along the protocol. At constant ventilation and body metabolism, pulmonary artery hypertension and decreases in CO had the biggest effects on the SnIII of the volumetric capnogram and on the elimination of CO2.
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J Clin Monit Comput · Feb 2015
Controlled Clinical TrialThe effect of endotracheal tube cuff pressure change during gynecological laparoscopic surgery on postoperative sore throat: a control study.
Postoperative respiratory complications related to endotracheal intubation usually present as cough, sore throat, hoarseness. The aim of the study was to examine the effects of endotracheal tube cuff pressure changes during gynecological laparoscopic surgery on postoperative sore throat rates. Thirty patients who underwent gynecological laparoscopic surgery and 30 patients who underwent laparotomy under general anesthesia with endotracheal intubation were included. ⋯ In both groups, the endotracheal tube cuff pressure and peak airway pressure were significantly correlated (R=0.9431, P<0.01; R=0.8468, P<0.01). Compared to patients who had undergone laparotomy, patients who had undergone laparoscopic surgery showed significantly higher sore throat scores at both 2 and 24 h after surgery (P<0.01). Pneumoperitoneum and Trendelenburg position may increase airway pressure and cuff pressure, resulting in increased incidence of postoperative sore throat.