Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Blackwell Futura Publishing, Inc.  (3)
  • 1
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: KETTERING, K., et al.: Enhanced Detection Criteria in Implantable Cardioverter Defibrillators: Sensitivity and Specificity of the Stability Algorithm at Different Heart Rates. Sensitivity and Specificity of the Stability Algorithm at Different Heart Rates. The lack of specificity in the detection of ventricular tachyarrhythmias remains a major clinical problem in the therapy with ICDs. The stability criterion has been shown to be useful in discriminating ventricular tachyarrhythmias characterized by a small variation in cycle lengths from AF with rapid ventricular response presenting a higher degree of variability of RR intervals. But RR variability decreases with increasing heart rate during AF. Therefore, the aim of the study was to determine if the sensitivity and specificity of the STABILITY algorithm for spontaneous tachyarrhythmias is related to ventricular rate. Forty-two patients who had received an ICD (CPI Ventak Mini I, II, III or Ventak AV) were enrolled in the study. Two hundred ninety-eight episodes of AF with rapid ventricular response and 817 episodes of ventricular tachyarrhythmias were analyzed. Sensitivity and specificity in the detection of ventricular tachyarrhythmias were calculated at different heart rates. When a stability value of 30 ms was programmed the result was a sensitivity of 82.7% and a specificity of 91.4% in the detection of slow ventricular tachyarrhythmias (heart rate 〈 150 beats/min). When faster ventricular tachyarrhythmias with rates between 150 and 169 beats/min (170–189 beats/min) were analyzed, a stability value of 30 ms provided a sensitivity of 94.5% (94.7%) and a specificity of 76.5% (54.0%). For arrhythmia episodes ≥ 190 beats/min, the same stability value resulted in a sensitivity of 78.2% and a specificity of 41.0%. Even when other stability values were taken into consideration, no acceptable sensitivity/specificity values could be obtained in this subgroup. RR variability decreases with increasing heart rate during AF while RR variability remains almost constant at different cycle lengths during ventricular tachyarrhythmias. Thus, acceptable performance of the STABILITY algorithm appears to be limited to ventricular rate zones 〈 170 beats/min.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Transvenous unipolar active can defibrillation systems have proven to be effective in treating ventricular tachyarrhythmias. However, a further reduction of ventricular defibrillation thresholds (V-DFT) would increase the longevity, reduce the size of pulse generators, and help to avoid additional leads in patients with inacceptable high V-DFTs. In a finite difference computer model, the extension of the right ventricular (RV) defibrillation coil into the low right atrium led to a 40% reduction of unipolar V-DFT. To evaluate this finding, we conducted a prospective, randomized study in 11 patients receiving an ICD. Extension of the RV electrode was simulated by adding a second coil placed in the low right atrium with the same polarity. Using a binary search protocol, V-DFT was determined with and without the additional electrode in each patient. Total shock impedance was significantly lower in the two coil (low RA) configuration, compared to the single coil (RV) configuration. Corresponding values were 49.9 ± 6.7 Ohm and 61.1 ± 9.3 Ohm, respectively (P 〈 0.01, paired t-test). However, there was no reduction, but even a nonsignificant increase in V-DFTs. Mean V-DFT in the RV configuration was 12.0 ± 5.6 J and 16.3 ± 7.8 J in the low RA configuration (P = 0.09, paired t-test). Despite a reduction in total impedance, the addition of a defibrillation coil in the low right atrium does not reduce ventricular defibrillation thresholds. (PACE 2004; 27:346–351)
    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: KETTERING, K., et al.: Efficacy of Metoprolol and Sotalol in the Prevention of Recurrences of Sustained Ventricular Tachyarrhythmias in Patients with an Implantable Cardioverter Defibrillator. ICDs provide protection against sudden cardiac death in patients with life-threatening ventricular arrhythmias. Nevertheless, most ICD recipients receive adjunctive antiarrhythmic drug therapy to reduce the number of recurrent episodes and ICD discharges. The aim of the study was to compare the efficacy of metoprolol and d,l-sotalol in preventing VT/VF recurrences in patients with an ICD in a prospective, randomized trial. One hundred patients (83 men, 17 women; mean age 59 years, SD ± 11 years) were randomized to receive metoprolol or sotalol after implantation of an ICD. There were no significant differences between the two groups with regard to age, sex, underlying cardiac disease, left ventricular ejection fraction, NYHA class assessment and clinical arrhythmia. The median follow-up was 728 days (25th percentile: 530 days, 75th percentile: 943 days) in the metoprolol group and 727 days (25th percentile: 472 days, 75th percentile: 1,223 days) in the sotalol group (P = 0.52). Thirty-three patients treated with metoprolol and 30 patients receiving sotalol had at least one episode during the follow-up. Event-free survival curves were generated for the two treatment arms using the Kaplan-Meier method and showed no significant difference (P = 0.68). Eight patients treated with metoprolol and six patients treated with sotalol died during follow-up. Total mortality was not significantly different between the two study groups (P = 0.43). Metoprolol is as efficacious as sotalol in preventing VT/VF recurrences in patients with an ICD.
    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...