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  • 1
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148 , USA , and 9600 Garsington Road , Oxford OX4 2XG , UK . : Blackwell Publishing, Inc.
    Annals of noninvasive electrocardiology 9 (2004), S. 0 
    ISSN: 1542-474X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: The aim of the present study was to determine the potential role of P wave duration and P wave dispersion for risk assessment of atrial tachyarrhythmias in patients with corrected tetralogy of Fallot (ToF). Methods: The maximum P wave duration, minimum P wave duration, and the P wave dispersion from the 12-lead surface electrocardiogram of the patients and controls were measured. Electrophysiological study was performed only in the patient group. Results: The study group consisted of 25 patients with corrected ToF with a mean age of 16.4 ± 4.25 years and 25 age-matched healthy control subjects. Patients underwent repair at a mean age of 4.6 ± 3.41 years (range: 1–19), and the mean duration of follow-up of 11.8 ± 1.7 years (range: 9–15) after surgery. On electrophysiological study sinus node dysfunction was detected in 3 patients (12%), atrial tachyarrythmias—atrial flutter or fibrillation—in 5 patients (20%), both sinus node dysfunction and atrial flutter in 1 patient (4%), and AV conduction delay in 1 patient (4%). P wave dispersion is significantly higher in patients with atrial tachyarrhythmia inducible by electrophysiological study than in other patients (P 〈 0.05). A P wave dispersion value of 〉35 ms has a high predictive accuracy (sensitivity = 83% and specificity = 89%) for inducible atrial tachyarrhythmia in patients with corrected tetralogy of Fallot. Conclusion: P wave dispersion is an easily measured electrocardiographic marker with a good sensitivity and specificity for predicting atrial arrhythmias in patients after correction of ToF.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 27 (2004), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Isolated noncompaction of the ventricular myocardium is a rare unclassified cardiomyopathy and is thought to be due to arrest of myocardial morphogenesis. In fetal life, it is characterized by an excessively prominent trabecular meshwork and deep intratrabecular recesses, and occurs in the left ventricle in the absence of structural heart disease. Echocardiography provides evidence for the diagnosis. The noncompacted ventricular myocardium may be accompanied by depressed ventricular function, systemic embolism, Wolff-Parkinson-White syndrome, left bundle branch block, and ventricular arrhythmia. Although onset of symptoms is frequently delayed until adulthood, symptomatic children have a poor prognosis. In this report, we describe a case of 6-year-old girl who had a history of recurrent syncope. Transthoracic echocardiographic examination showed a localized prominent trabeculation and deep intratrabecular recesses at the inferoapical region of the left ventricle. She had several episodes of ventricular fibrillation which was refractory to pharmacological treatment. An implantable cardioverter defibrillator (ICD) was successfully operated three times during follow-up. (PACE 2004; 27:104–108)
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 25 (2002), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: ELSHERSHARI, H., et al.: Influence of D-Net (EUROPEAN GSM-Standard) Cellular Telephones on Implanted Pacemakers in Children. This study was designed to evaluate possible interactions between digital cellular telephones and implanted pacemakers in children. The study comprised 95 patients (53 males and 42 females) with a mean age of 11.5 ± 4.6 years (range 1–22 years). The average time from pacemaker implantation was 2.5 years (range 1 month–12 years). Fourteen (15%) devices were dual chamber and the remaining were single chamber pacemakers. The following companies manufactured the pacemakers tested: Medtronic (n = 42), Telectronics (n = 9), Vitatron (n = 16), Pacesetter (n = 19), CPI (n = 8), and Biotronik (n = 1). All the patients were tested in the supine position during continuous ECG monitoring. After completion of the routine pacemaker check, the effects of the European Global system for mobile communication (GSM) was tested using two cellular telephone models (Ericsson GA 628 and Siemens S 25, 2-W power). For this purpose, atrial and ventricular sensitivity settings were programmed to the most sensitive values, and the tests were carried out in the unipolar and bipolar sensing modes. The evaluation was performed during ringing, switching on/off, and conversation phase with the cellular telephone positioned over the pulse generator and around the pacemaker pocket. A malfunction of the pacemaker was not observed in any patient. Only 1 (1%) of 95 patients showed a brief oversensing problem during calls with the cellular telephone. In this case, an AAIR pacemaker was implanted transvenously in a subcutaneous pocket and the sensing defect occurred only with the unipolar sensing mode and was not reproducible. Once the source of interference was removed, no sensing defect was detected and the patient remained asymptomatic. No symptoms were experienced in this study. The authors believe that pacemaker dependent patients with nonprotected pulse generators manufactured at the beginning of 1990s may be tested by their physicians for possible interferences before they use a digital cellular telephone.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Although active fixation ventricular leads seem to have advantages over passive fixation leads, this study compares the follow-up results of active and passive fixation leads in children. We evaluated the implantation and follow-up data of 41 children with active (Ac-cufix II DEC, group 1) (n = 20) or passive (Membrane E, group 2) (n = 21) fixation, steroid-eluting ventricular leads. All but one of the patients in group 1 completed the 12-month follow-up. The mean follow-up period in group 2 was 10.4 ± 2.9 months (range 3–12 months, median 12 months). In both groups the mean pacing threshold was measured as 0.51 ± 0.09 V versus 0.48 ± 0.15 V (P 〉 0.05) at 0.5-ms pulse width, mean R wave amplitude as 9.9 ± 2.5 m V versus 9.4 ± 3.2 mV (P 〉 0.05), and mean impedance as 557 ± 92 Ω versus 664 ± 160 Ω (P 〈 0.05), respectively, at implantation. After the first week of pacing, mean threshold values in group 1 were significantly lower than those of group 2 (P 〈 0.01 and P 〈 0.05, respectively). During the follow-up period, lead impedance measurements did not show a significant difference between the two groups. In one patient from group 1, the lead (by unscrewing) was removed easily because of pacemaker pocket infection. No lead dislodgement or helix deformation occurred in group 1. Nevertheless, in one patient from group 2, the lead was extracted at 4-month postimplantation because of lead displacement. We conclude that the steroid-eluting active fixation lead (Accufix II DEC) have advantages of easier implantation and lower acute and chronic stimulation thresholds compared to the passive fixation lead (Membrane E). Therefore, Accufix II DEC is superior to Membrane E, and it is a better first choice in children with an implanted single chamber ventricular pacemaker.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Rate adaptive pacemakers are used to achieve a better cardiac performance during exercise by increasing the heart rate and cardiac output. The ideal rate adaptive sensor should be able to mimic sinus node modulation under various degrees of exercise and other metabolic needs. Minute ventilation sensing has proven to be one of the most accurate sensor systems. In this study, alterations in sinus rhythm and pacing rates during daily life conditions in 11 children (median age 11 years, range 6–14 years) with minute ventilation single chamber pacemakers were investigated. Correlation of sinus rhythm with pacing rates was assessed. ECG records were obtained from 24–hour Holter monitoring. Average rates of five consecutive P waves and pace waves were determined every half hour. The average of the two values was then used to determine hourly rates. Correlation coefficients between the sinus rhythm and pacing rates were calculated. In nine patients, pacing rates correlated well to sinus rhythm (range 0.6793–0.9558. P 〈 0.001 and P 〈 0.05), whereas in two cases correlation was not sufficient (P 〉 0.05). Most of the patients, in whom rate response factor (RRF) measurements during peak exercise by treadmill with cnronotropic assessment exercise protocol were performed and pacemakers were programmed to these parameters, had more appropriate ventricular rates compared to spontaneous sinus rates. In these patients mean RRF value was 15.3 ± 2.7 (range 12–20, median 15). This study shows that during daily activities minute ventilation rate adaptive pacemakers can achieve pacing rates well correlated to sinus rhythm that reflects the physiological heart rate in children.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 20 (1997), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Head-up tilt testing with or without isoproterenol is extensively used in the evaluation of patients with unexplained syncope. However, sensitivity and specificity of tilt protocols with and without isoproterenol have not been clarified in children, due to lack of age matched control subjects. This study was designed to assess and to compare the sensitivity and specificity of tilting alone and tilting in conjunction with isoproterenol. Thirty children with unexplained syncope (group I) and 15 age-matched control subjects (control group I) underwent successive 60° head-up tilts for 10 minutes during infusions of 0.02, 0.04, and 0.06 μg/kg/min of isoproterenol, after a baseline tilt to 60° for 25 minutes. Also, 35 children (group II) with unexplained syncope and 15 healthy control subjects (control group II) were evaluated by head-up tilt to 60° for 45 minutes without an infusion of isoproterenol. In response to tilt protocol with graded isoproterenol, 23 (76.6%) of the patients in group I and 2 of the 25 (13.3%) control subjects developed syncope. Accordingly, the sensitivity of tilt testing with isoproterenol was 76.6%, and its specificity was 86.7%. Tilt testing without isoproterenol was positive in 17 (48.5%) of the patients in group II but in only 1 of the 15 (6.6%) control subjects. Thus, sensitivity and specificity of tilt testing without isoproterenol were 48.5% and 93.4%, respectively. The mean heart rate and systolic blood pressure decreased significantly (P 〈 0.001) in all tilt positive patients during syncope. In conclusion, the head-up tilt test is a valuable diagnostic test in the evaluation of children with unexplained syncope, and isoproterenol is likely to increase the sensitivity of the test without decreasing its specificity.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 25 (2002), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: DILBER, E., et al.: Permanent Transfemoral Pacemaker Implantation in a Child with Maroteaux Lamy Syndrome. Permanent transfemoral pacing has been described as an alternative route in patients in whom the superior venous approach is not feasible. This report describes the use of the femoral venous approach to insert a permanent pacemaker in a child with Maroteaux Lamy syndrome who has complete atrioventricular block and abnormal subclavian venous anatomy. Transfemoral pacing may be a suitable alternative in children with short stature.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 20 (1997), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Dual sensor pacemakers were developed to obtain more appropriate responses to activity. We evaluated ten children with dual sensor pacemakers in different sensor blending circumstances using exercise testing to assess which ratio was optimal. Ten patients with several bradydysrhythmias (ages 6-16 years; mean 10.1 years) were included in the study. Eight patients had WIR pacemakers (Vitatron Topaz), models and two patients had VDD pacemakers implanted via the transvenous route. All patients were in a paced rhythm (98.5% pacing). Accurate T wave sensing ranged from 81%-100%; mean 92%, median 95%. Voluntary exercise testing with a CAEP protocol was performed using a treadmill with the pacemaker in WIR mode. Medium activity threshold with three sensor blending ratios (QT = ACT, QT 〉 ACT, and QT 〈 ACT) were done in all patients. The mean duration of exercise was not statistically different among the three sensor blending ratios. After 90 seconds of exercise, the mean pacing rate had increased by 12%, 3%, and 5%, respectively, in the three groups. At maximal exercise, the increases were 45%, 42%, and 54%. Mean HRs during exercise in each of the three ratios were not significantly different, although we found a statistically significant increase in HR during the first two stages of rest period in the QT = ACT sensor blending ratio compared to the QT 〉 ACT ratio. No difference was observed after the second stage. In conclusion: (1) there is no difference between the QT = ACT, QT 〈 ACT, and QT 〉 ACT sensor blending ratios; and (2) each child has to be evaluated by exercise testing to program a correct sensor blending ratio. (PACE 1997; 20[Pt. I]:1301-1304)
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Pacing and clinical electrophysiology 28 (2005), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Isolated ventricular noncompaction (IVNC) is a serious cardiomyopathy with a generally poor prognosis. It is characterized by the presence of prominent ventricular myocardial trabeculations and deep intertrabecular recesses, in the absence of other structural heart defects. This cardiomyopathy is usually associated with ventricular dysfunction, thromboembolic events, and rhythm problems. Methods and Results: This article describes 11 children who have rhythm abnormalities associated with IVNC. On admission, eight children had complaints including palpitation, syncope, heart failure, and bradycardia. Ventricular arrhythmias were diagnosed in four children, sinus node and atrioventricular conductance disturbances in six children, and Wolff-Parkinson-White syndrome and associated tachycardia in one child. Three children with ventricular arrhythmias received an automatic implantable cardioverter defibrillator (ICD). Three patients died of cardiac problems during the follow-up period. Conclusion: Since many of rhythm abnormalities, including life-threatening ventricular arrhythmias, may be seen in patients with IVNC, children with IVNC should be screened for arrhythmias. An ICD may be the best treatment for some of these patients.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 25 (2002), S. 0 
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: KUCUKOSMANOGLU, O., et al.: Compatibility of Automatic Threshold Tracking Pacemakers with Previously Implanted Pacing Leads in Children. The Autocapture function controls and optimizes the amplitude of the pacing pulse and saves energy. The manufacturer recommends using a special low polarization, low threshold bipolar Pacesetter lead for the Autocapture function. The purpose of this study was to evaluate the compatibility of Autocapture with previously implanted pacing leads. The study included 15 patients (mean age 13.6 ± 3.4 years) who needed pulse generator replacement and received the VVIR pacemaker Regency SR+ or the DDDR pacemakers Affinity DR or Integrity DR with the Autocapture function. The new pulse generators connected to previously implanted ventricular leads. At the time of implantation the pacing threshold was 1.0 ± 0.35 V at 0.5 ms, the lead impedance was 580 ± 80 Ω, and the spontaneous R wave amplitude was 7.89 ± 4.89 mV. The polarization signal (PS) was 3.8 ± 3.04 mV, and evoked response (ER) was 8.15 ± 4.57 mV at the predischarge testing. Follow-up telemetry was done at months 1, 3, 6, 12, and 18. The follow-up duration was 9.4 ± 5 months (range 1–18 months). If the results of PS and ER measurements were acceptable for Autocapture, it turned on at the 1-month visit. In six (40%) patients the results were found acceptable for Autocapture function. Age, lead impedance, pacing threshold, intrinsic R wave measurement, lead age, fixation mechanism, and ER measurements were not statistically different in Autocapture suitable and not suitable groups. The main reason not to activate Autocapture had been increased PS. Any significant fluctuations were not observed in pacing threshold, lead impedance, ER, and PS during follow-up. In conclusion, previously implanted pacing leads may be compatible with the Autocapture function.
    Type of Medium: Electronic Resource
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