Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of the study was to compare the specificity of dual chamber ICDs detection algorithms for correct classification of supraventricular tachyarrhythmias derived from clinical studies according to their size to detect an impact of sample size on the specificity. Furthermore, the study sought to compare the specificities of detection algorithms calculated from clinical data with the specificity calculated from simulations of tachyarrhythmias. A survey was conducted of all available sources providing data regarding the specificity of five dual chamber ICDs. The specificity was correlated with the number of patients included, number of episodes, and number of supraventricular tachyarrhythmias recorded. The simulation was performed using tachyarrhythmias recorded in the electrophysiology laboratory. The range of the number of patients included into the studies was 78–1,029, the range of the total number of episodes recorded was 362–5,788, and the range of the number of supraventricular tachyarrhythmias used for calculation of the specificity for correct detection of these arrhythmias was 100 (Biotronik) to 1662 (Medtronic). The specificity for correct detection of supraventricular tachyarrhythmias was 90% (Biotronik), 89% (ELA Medical), 89% (Guidant), 68% (Medtronic), and 76% (St. Jude Medical). There was an inverse correlation (r =−0.9, P = 0.037) between the specificity for correct classification of supraventricular tachyarrhythmias and the number of patients. The specificity for correct detection of supraventricular tachyarrhythmias calculated from the simulation after correction for the clinical prevalence of the simulated tachyarrhythmias was 95% (Biotronik), 99% (ELA Medical), 94% (Guidant), 93% (Medtronic), and 92% (St. Jude Medical). In conclusion, the specificity of ICD detection algorithms calculated from clinical studies or registries may depend on the number of patients studied. Therefore, a direct comparison between different detection algorithms based on clinical data is difficult. In contrast, simulation of supraventricular tachyarrhythmias using a uniform database may be a better tool for direct comparison of the specificity of ICD detection algorithms. (PACE 2004; 27:976–982)
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 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.
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cardiac function and electrical stability may be improved by programming of optimal AV delay in DDD pacing. This study tested the hypothesis if the global atrial conduction time at various pacing sites can be derived from the surface ECG to achieve an optimal electromechanical timing of the left heart. Data were obtained from 60 patients following dual chamber pacemaker implantation. Right atrial septal pacing was associated with significantly shorter atrial conduction time (P 〈 0.0005) and P wave duration (P 〈 0.005), compared to standard right atrial pacing sites at the right atrial appendage or at the right free wall. The last two pacing sites showed no significant difference. In a group of 31 patients with AV block, optimal AV delay was achieved by programming a delay of 100 ms from the end of the paced P wave to peak/nadir of the paced ventricular complex. Optimization of AV delay resulted in a relative increase of echocardiographic stroke volume (SV) (10.9 ± 13.7%; 95% CI: 5.9–15.9%) when compared to nominal AV delay (170 ms). Optimized AV delay was highly variable (range 130–250 ms; mean 180 ± 35 ms). The hemodynamic response was characterized by a weak significant relationship between SV increase and optimized AV delay (R2= 0.196, R = 0.443, P = 0.047). The study validated that septal pacing is advantageous for atrial synchronization compared to conventional right atrial pacing. Tailoring the AV delay with respect to the surface ECG improved systolic function significantly and was superior to nominal AV delay settings in the majority of patients. (PACE 2004; 27:468–474)
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We report the case of an 85-year-old woman with distal LV hypertrophy resulting in an intraventricular pressure gradient and incomplete systolic emptying who benefited from permanent DDD pacing. Our experience based on this case suggests that permanent dual chamber pacing might be a safe and effective therapy also in symptomatic patients with the rare form of hypertrophic cardiomyopathy with left mid-ventricular obstruction resulting in incomplete emptying of the apical portion of the LV and a significant intraventricu- lar pressure gradient that was not responding to pharmacological therapy.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1540-8167
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction: Biventricular pacing has been shown to improve the clinical status of patients with congestive heart failure, but little is known about its influence on ventricular repolarization. The aim of our study was to evaluate the effect of biventricular pacing on ECG markers of ventricular repolarization in patients with congestive heart failure. Methods and Results: Twenty-five patients with congestive heart failure, sinus rhythm (SR), and complete LBBB (6 females; age 61 ± 8 years; NYHA class II–III; echocardiographic ejection fraction 21 ± 5%; QRS ≥ 130 ms) underwent permanent biventricular DDDR pacemaker implantation. A high-resolution 65-lead body-surface ECG recording was performed at baseline and during right-, left-, and biventricular pacing, and the total 65-lead root mean square curve of the QRST complex and the interlead QT dispersion were assessed. The QRS duration was increased during right (RV)- and left ventricular (LV) pacing (127 ± 26% and 117 ± 40%; P 〈 0.05), as compared to SR (100%) and biventricular pacing (93 ± 16%; ns). The QTc interval was increased during RV and LV pacing (112 ± 12% and 114 ± 14%; P 〈 0.05) as compared to SR (100%) or biventricular pacing (99 ± 12%). There was no effect on JT interval during all pacing modes. The Tpeak-end interval was increased during right (120 ± 34%; P 〈 0.01) and LV pacing (113 ± 29%; P 〈 0.05) but decreased during biventricular pacing (81 ± 19%; P 〈 0.01). A similar effect was found for the Tpeak-end integral and the Tpeak amplitude. QT dispersion was increased during right ventricular (129 ± 16 ms; P 〈 0.05) and decreased during biventricular pacing (90 ± 12 ms; P 〈 0.01), as compared to SR (114 ± 22 ms). Conclusions: Using a high-resolution surface ECG, biventricular pacing resulted in a significant reduction of ECG markers of ventricular dispersion of repolarization.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1540-8167
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Global P Wave Duration on the 65-Lead ECG. Introduction: Pacing is believed to prevent atrial fibrillation by reducing atrial activation time. Exact correlation between P wave duration (PWD) on surface ECG and endocardial atrial activation time is still unexplored. Methods and Results: In 15 patients without structural heart disease (9 women, age 45 ± 14 years), single site [high right atrium (HRA), coronary sinus ostium (CSos), distal CS (CSd), high RA septum (Bachmann's bundle, BB)] and dual-site pacing (various combinations) was performed after ablation of supraventricular tachycardia. A 65-lead surface ECG was recorded simultaneously. Endocardial atrial activation time was measured off-line (stimulus – last bipolar recording), and the respective PWD was assessed using the root mean square and 65-channel summary plots. PWD during pacing from BB was significantly shorter (96 ± 12 msec) than during HRA (121 ± 15 msec), CSos (108 ± 9 msec), and CSd pacing (126 ± 14 msec; P 〈 0,01, respectively). PWD during dual-site pacing (HRA + BB, 91 ± 14 msec; HRA + CSos, 96 ± 7 msec; HRA + CSd, 90 ± 7 msec; BB + CSd, 96 ± 12 msec) was not significantly shorter than during pacing from BB. Correlation between endocardial atrial activation time and PWD was 0.83. Conclusion: PWD during single-site and dual-site atrial pacing represents endocardial atrial activation time and can be measured precisely using the 65-lead surface ECG. The fact that high septal pacing results in the shortest PWD may have implications for preventive pacing in patients with atrial fibrillation.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148-5018 , USA , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    ISSN: 1540-8167
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction: Atrial arrhythmias have emerged as a topic of great interest for clinical electrophysiologists. Noninvasive imaging of electrical function in humans may be useful for computer-aided diagnosis and treatment of cardiac arrhythmias, which can be accomplished by the fusion of data from ECG mapping and magnetic resonance imaging (MRI). Methods and Results: In this study, a bidomain-theory–based surface heart model activation time (AT) imaging approach was applied to paced rhythm data from four patients. Pacing sites were the right superior pulmonary vein, left inferior pulmonary vein, left superior pulmonary vein, coronary sinus, posterior wall of right atrium, and high right atrium. For coronary sinus pacing, the AT pattern of the right atrium was compared with a CARTO map. The root mean square error between CARTO geometry (85 nodal points) and the surface model of the right atrium was 8.6 mm. The correlation coefficient of the noninvasively obtained AT map of the right atrium and the CARTO map was 0.76. All pulmonary vein pacing sites were identified. The reconstructed pacing site of right posterior atrial pacing correlates with the invasively determined pacing catheter position with a localization distance of 4 mm. Conclusion: The individual anatomic model of the atria of each patient enables accurate noninvasive AT imaging within the atria, resulting in a localization error for the pacing sites within 10 mm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias or focal triggers. (J Cardiovasc Electrophysiol, Vol. 14, pp. 712-719, July 2003)
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: As pacemaker generator longevity is dependent on current consumption and resistance of the pacing lead, the use of a high impedance pacing lead theoretically results in an extension of battery longevity. Therefore, the effect of high versus standard impedance ventricular leads on generator longevity was studied. In 40 patients (21 women, age 73 ± 13 years) with a standard dual chamber pacemaker indication, a bipolar standard impedance ventricular lead was implanted in 20 patients, the remaining patients received a bipolar high impedance lead in a randomized fashion. All patients received identical pacemaker generators and atrial leads. The estimated longevity of the generator was calculated automatically by a programmed pacemaker algorithm. After a mean follow-up of 39 ± 4.8 months, no significant differences were observed with respect to mean pacing and sensing thresholds of the atrial and ventricular leads in both groups. However, the high impedance leads displayed a significantly higher impedance and a significantly lower current drain as compared to standard impedance leads (1,044 ± 139 vs 585 ± 90 Ω, and 2.2 ± 0.4 vs 4.3 ± 1.1 mA). The extrapolated generator longevity was significantly longer in the high impedance lead group, as compared to the standard impedance lead group (107.3 ± 8.5 vs 97.6 ± 9.0 months; P = 0.02). In conclusion, implantation of a high impedance lead for ventricular pacing results in a clinically relevant extension of generator longevity. (PACE 2003; 26:2116–2120)
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: HINTRINGER, F., et al.: Inappropriate Detection of Supraventricular Arrhythmias by Implantable Dual Chamber Defibrillators: A Comparison of Four Different Algorithms. Inappropriate therapy of supraventricular tachyarrhythmias by an ICD is still a common problem. Dual chamber (DDD) ICDs provide additional atrial sensing and should result in higher specificity for detection of supraventricular tachyarrhythmias. However, a direct comparison of different dual chamber algorithms has not been reported. The detection algorithms of four different DDD ICDs were tested: Phylax AV, Defender IV, Ventak AV III DR, and Gem DR 7271. Based on arrhythmias recorded from patients undergoing invasive electrophysiological studies and in many cases of catheter ablation at our institution, a library consisting of 71 supraventricular and 15 ventricular tachyarrhythmias was created. The library consists of episodes of atrial fibrillation, atrial flutter with different AV conduction, typical and atypical AV nodal reentrant tachycardia, AV reentrant tachycardia, sinus tachycardia, and ventricular tachycardia with and without ventriculoatrial conduction. Atrial fibrillation was appropriately classified by all four algorithms. However, the specificity for detection of other supraventricular tachyarrhythmias achieved by the Biotronik (12%) and the Guidant (11%) devices was significantly lower compared to the specificity of the ELA (28%) and the Medtronic DDD ICD (20%). This is due to the fact that the Biotronik and the Guidant algorithm classified all supraventricular tachyarrhythmias resulting in a stable ventricular rate as ventricular tachycardia, whereas the ELA and Medtronic algorithms performed a more detailed analysis by assessment of PR association, atrial onset, or timing of the atrial event relative to the ventricular event, respectively. Atrial fibrillation, the most common supraventricular tachyarrhythmia in patients with ICD, was detected by all devices.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...