GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

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
    Impact of Atrial Fibrillation on the Voltage of Bipolar Signals Acquired from the Left and Right Atria (2003)
    P.O. Box 418, Armonk, NY 10504-0418. : Blackwell Publishing
    Pacing and clinical electrophysiology 26 (2003), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: NDREPEPA, G., et al.: Impact of Atrial Fibrillation on the Voltage of Bipolar Signals Acquired from the Left and Right Atria. A detailed analysis of the impact of atrial fibrillation (AF) on the voltage of the atrial signals acquired from various right and left atrial regions has not been reported. Thirteen patients (mean age 55 ± 11 years, range 39–67 years, 5 women) with AF were included in this study. Mapping of the left and the right atrium was performed with 64-electrode basket catheters. AF cycle lengths were calculated over 10-second time intervals using a custom-made software. Voltage of the bipolar signals during AF was calculated by measuring the amplitudes of 30 consecutive signals in the left and the right atria. During sinus rhythm voltage differences between the left (3 ± 2.9 mV) and the right atrium (2.8 ± 2.4 mV, P = 0.15) were insignificant. During AF, as compared to sinus rhythm, voltages of the bipolar signals were significantly reduced in the left (0.9 ± 0.6 mV) and the right (1.3 ± 1.1 mV) atria ( P 〈 0.001 compared with sinus rhythm). In the left atrium, the posterior wall showed the most pronounced voltage reduction ( 1.1 ± 0.8 mV vs 5.3 ± 4.6 mV, P 〈 0.001 ). In the right atrium the septal wall showed the greatest reduction in voltage amplitude ( 0.8 ± 0.6 mV vs 2.5 ± 1.5 mV, P 〈 0.001 ). There was a close correlation between the voltage values and the AF cycle length. The smallest voltage values and greatest amplitude reductions were observed during faster and more disorganized AF activity. It is concluded that during AF, the voltage of bipolar signals is significantly reduced as compared to sinus rhythm. The reduction in voltage expresses atrial and regional disparity and correlates strongly with local AF cycle lengths and the degree of AF disorganization. (PACE 2003; 26[Pt. I]:862–869)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9592.2003.t01-1-00151.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Single Chamber Atrial Fibrillation Involving Only the Left Atrium: (2003)
    P.O. Box 418, Armonk, NY 10504-0418. : Blackwell Publishing
    Pacing and clinical electrophysiology 26 (2003), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: KARCH, M.R., et al.: Single Chamber Atrial Fibrillation Involving Only the Left Atrium: Implications for Maintenance and Radiofrequency Ablation Therapy. Due to the anatomic and the functional interatrial relationship, AF is a biatrial process. Whether one of the atria could sustain AF is not known. This study included 11 patients (mean age ± 1 years, 7 men) with AF who showed a distinct activation pattern, characterized by regular activity in the right atrium (RA) and irregular fibrillatory activity confined to the left atrium (LA) throughout the AF episodes. Each of the atria was mapped with 64-electrode basket catheters. AF was monitored for 74 ± 26 minutes . Complex and irregular activity with a cycle length of 138 ± 43 ms was observed in the LA throughout the monitoring time. The posterior and the roof of the LA showed the highest degree of disorganization. RA was activated by regular wavefronts with a cycle length of 194 ± 22 ms ( P 〈 0.001 , compared with LA). No fibrillatory activity was observed in the RA. All wavefronts that activated the RA were of septal origin: high anteroseptal 52%, low posteroseptal 22%, mid-septal 18, and dual wavefronts (from the high anteroseptal and low posteroseptal pathways) 8%. The lateral wall of the RA was activated in a superoinferior direction in 82% of all activations. A left-to-right conduction block during AF and a rotor of fibrillatory activity located in the posterior wall of the LA were observed in two patients. Isolated AF in the LA showed various surface electrocardiographic patterns. It is concluded that LA alone without participation of the RA can sustain AF. These data have implications for mechanisms and the ablative therapy of AF. (PACE 2003; 26[Pt. I]:883–891)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9592.2003.t01-1-00154.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Pulmonary Vein Internal Electrical Activity Does Not Contribute to the Maintenance of Atrial Fibrillation (2003)
    350 Main Street , Malden , MA 02148-5018 , U.S.A . : Blackwell Publishing
    Pacing and clinical electrophysiology 26 (2003), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Whether the electrical activity generated in the pulmonary veins (PVs) during atrial fibrillation (AF) contributes to the maintenance of arrhythmia is not known. The study population consisted of 22 patients (mean age 58 ± 9.5 years, 16 men) with persistent (12 patients) or intermittent (10 patients) AF. Mapping of the left atrium (LA) was performed with a 64-electrode basket catheter. PVs were mapped simultaneously with the LA with a quadripolar catheter. PV were defined as arrhythmogenic (if frequent ectopic activity induced AF) or nonarrhythmogenic (if no ectopic activity was observed during the procedure). AF cycle lengths in arrhythmogenic and nonarrhythmogenic PV were 130 ± 50 ms and 152 ± 42 ms, respectively (P 〈 0.001) . Both were significantly longer than simultaneous AF activity recorded from the posterior wall of the LA (116 ± 49 ms, P 〈 0.001) . AF cycle lengths in arrhythmogenic PVs as compared to nonarrhythmogenic PVs were: right superior PV 125 ± 49 ms versus 148 ± 51 ms ; left superior PV 140 ± 52 ms versus 161 ± 30 ms ; left inferior PV 127 ± 48 ms versus 147 ± 45 ms ; and right inferior PV 129 ± 38 versus 152 ± 44 ms ( P 〈 0.001 for all four comparisons). AF activity in the PV was more organized than in the posterior wall of the LA and the veins were activated in a proximal-to-distal direction during sustained AF episodes. In patients with AF not related to rheumatic heart disease, the posterior wall of the LA has faster activity than the PVs. The AF activity generated inside the PV during sustained AF episodes originates from the posterior wall of the LA rather than from focal firing. (PACE 2003; 26:1356–1362)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9592.2003.t01-1-00194.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Electrophysiological evidence for delayed mismatch response in infants at-risk for specific language impairment (2004)
    Oxford, UK : Blackwell Publishing
    Psychophysiology 41 (2004), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: The present study investigated whether delayed auditory processing typically found in children with specific language impairment (SLI) can already be observed in the event-related potentials of 2-month-old infants. Infants with and without a family history of SLI were tested in a passive auditory oddball paradigm with CV-syllables differing in vowel duration. For the long syllable, a positive mismatch response occurred in the difference wave between deviant and standard. Its amplitude was higher in infants during quiet sleep than in awake infants, although its peak latency remained unaffected by alertness. Awake infants showed an adultlike mismatch negativity preceding the positivity. Risk for SLI was reflected in the latency of the positive mismatch response, which was delayed in infants with risk compared to infants without risk. This latency difference suggests that 2-month-old infants at risk for SLI are already affected in processing an auditory stimulus change of duration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.2004.00202.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...