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General anesthesia is sometimes required during radiofrequency catheter ablation (RFCA) of various tachyarrhythmias because of an anticipated prolonged procedure and the need to ensure stability during critical ablation. In this study, we examine the feasibility of using propofol anesthesia for RFCA procedure. There were 150 patients (78 male, 72 female; mean age 30 years, range 4-96 years) in the study. Electrophysiologic study was performed before and during propofol infusion in the initial 20 patients and was performed only during propofol infusion in the remaining 130 patients. In the initial 20 patients, propofol infusion increased the sinus rate and facilitated AV nodal conduction. The accessory pathway effective refractory period, as well as the sinus node recovery time, atrial effective refractory period, and ventricular effective refractory period were not significantly changed. There were 152 tachyarrhythmias in 150 patients (24 atrial flutter, 31 AV nodal reentrant tachycardia, 68 AV reciprocating tachycardia, 12 ventricular tachycardia, and 17 atrial tachycardia). Most (148/152) tachycardias remained inducible after anesthesia and RFCA was performed uneventfully. However, in four of the seven pediatric patients with ectopic atrial tachycardia, the tachycardia terminated after propofol infusion and could not be induced by isoproterenol infusion. Consequently, RFCA could not be performed. Intravenous propofol anesthesia is feasible during RFCA for most tachyarrhythmias except for ectopic atrial tachycardia in... [ABSTRACT FROM AUTHOR]

Aims Connective tissue growth factor ( CTGF) is an emerging marker for tissue fibrosis. We investigated the association between CTGF and cardiac diastolic function using cellular and animal models and clinical human data. Methods and results A total of 125 patients with a diagnosis of diastolic heart failure ( DHF) were recruited from 1283 patients of the Taiwan Diastolic Heart Failure Registry. The severity of DHF was determined by tissue Doppler imaging (E/e′). Cardiac magnetic resonance imaging ( CMRI) was used to evaluate myocardial fibrosis in some of the patients ( n = 25). Stretch of cardiomyocytes on a flexible membrane base serves as a cellular phenotype of cardiac diastolic dysfunction ( DD). A canine model of DD was induced by aortic banding. A significant correlation was found between plasma CTGF and E/e′ in DHF patients. The severity of cardiac fibrosis evaluated by CMRI also correlated with CTGF. In the cell model, stretch increased secretion of CTGF from cardiomyocytes. In the canine model, myocardial tissue CTGF expression and fibrosis significantly increased after 2 weeks of aortic banding. Notably, the expression of CTGF paralleled the severity of LV DD ( r = 0.40, P < 0.001 for E/e') and haemodynamic changes ( r = 0.80, P < 0.001). After adjusting for confounding factors, CTGF levels still correlated with diastolic parameters in both human and canine models (human plasma CTGF, P < 0.001; canine tissue CTGF, P = 0.04). Conclusion Plasma CTGF level correlated with the severity of DD and tissue fibrosis in DHF patients. The mechanism may be through myocardial stretch. Our study indicated that CTGF may serve as an early marker for DHF. [ABSTRACT FROM AUTHOR]

Up-Regulation of MLC-2V in Atrial Fibrillation. Introduction: Functional and structural changes of atrial tissue occur during the natural course of atrial fibrillation (AF), and these changes may contribute to further AF. We investigated the changes in AF tissue using cDNA microarray and two-dimensional protein electrophoresis techniques. Methods and Results: We established a porcine model of AF by rapid right atrial appendage pacing at a rate of 600/min. Atrial tissue was obtained after rapid atrial depolarization for 6 weeks. Microarrays containing 6,035 cDNA clones were used to evaluate the alterations of mRNA. Two-dimensional protein electrophoresis was performed to compare protein patterns. In cDNA microarray studies, we identified 387 genes with significant change in the left atrium and 81 genes in the right atrium. Among the genes, the ventricular isoform of the myosin regulatory light chain (MLC-2V) showed the greatest fold of change (9.4 and 7.3 in the left and right atrium, respectively). In protein electrophoresis, the expression levels of three protein spots spanning from 18 to 20 kDa in the acidic region (PI 4.5–5.0) were specifically elevated in the AF group. Interestingly, through tandem mass spectrometric analysis, these three spots were identified as MLC-2V. Thus, MLC-2V expression at the mRNA and protein levels corresponded well, and both indicated a significant increase in AF. Conclusion: Both cDNA microarray and two-dimensional polyacrylamide protein electrophoresis studies revealed characteristic changes in AF tissue. We demonstrated the reprogramming of myosin regulatory light chain isoform composition, with a significant increase of its ventricular isoform (MLC-2V). (J Cardiovasc Electrophysiol, Vol. 15, pp. 214-223, February 2004) [ABSTRACT FROM AUTHOR]

We studied the hypothermic effect of adding 150 μg morphine during spinal anaesthesia in 60 parturients scheduled for elective caesarean section. All the parturients received intrathecal injection of a solution containing 150 μg morphine or normal saline in addition to 10–12 mg hyperbaric bupivacaine 0.5%. In both groups, a significant decrease in body temperature was noted. There was no difference in the area under the curve for temperature against time for the two groups; however, the maximum decrease in temperature from baseline was significantly larger after morphine than after saline injection (mean (SD) 1.11 (0.61) °C vs 0.76 (0.39) °C, respectively; p = 0.01) and the time to nadir temperature was significantly longer (59.5 (17.6) min vs 50.4 (15.9) min, respectively; p = 0.047). The lowest temperature observed in the morphine group was 34.3 °C. We conclude that intrathecal injection of 150 μg morphine intensified the intra-operative hypothermic effect of bupivacaine spinal anaesthesia for caesarean section. [ABSTRACT FROM AUTHOR]

Presents the table of contents of the September 1999 issue of "Pace."