Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1
    Digitale Medien
    Digitale Medien
    Human Histopathology of Electroanatomic Mapping After Cooled-Tip Radiofrequency Ablation to Treat Ventricular Tachycardia in Remote Myocardial Infarction (2005)
    350 Main Street , Malden , MA 02148-5018 , USA , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Journal of cardiovascular electrophysiology 16 (2005), S. 0 
    Details
    ISSN: 1540-8167
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Introduction: Catheter ablation of ventricular tachycardia (VT) in remote myocardial infarction (MI) often requires excessive mapping procedures. Documentation of the electrical substrate via electrogram amplitude may help to identify regions of altered myocardium resembling exit areas of reentrant VTs. Methods and Results: A patient with multiple symptomatic monomorphic VTs (biventricular ICD, remote MI) underwent electroanatomic substrate mapping (CARTO™) for VT ablation. Regions of scar (bipolar electrogram amplitudes ≤0.5 mV), normal myocardium (≥1.5 mV), and “altered” myocardium (0.5–1.5 mV) were identified. Ablation was directed to regions with “altered” myocardium based on pace map correlation. After ablation the clinical VT did not reoccur. The patient died due to worsening of heart failure 7 days afterward. During postmortal evaluation specified sites of electroanatomic mapping were correlated to histopathological findings. Annotated scar areas were documented to consist of areas with massive fibrosis (≥80% of mural composition). Ablations were found to span through regions with intermediate fibrosis (21–79%) mapped as “altered” myocardium. Ablation produced transmural coagulation necrosis of mesh-like fibrotic tissue with interspersed remnants of myocardial cells up to a maximum depth of 7.0 mm. Subendocardial intramural bleedings were universal findings 7 days after ablation. Conclusions: Electroanatomic substrate mapping for VT ablation sufficiently identified regions of scar and normal myocardium. Regions with bipolar electrogram amplitudes between 0.5 and 1.5 mV were found to correlate to areas of “intermediate” fibrosis (21–79%) with only remnant strands of myocardial cells and were identified as target region for ablation. Cooled-tip endocardial radiofrequency ablation lead to transmural coagulation necrosis up to a depth of 7.0 mm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1540-8167.2005.40826.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Pace-Termination and Pacing for Prevention of Atrial Tachyarrhythmias: Results from a Multicenter Study with an Implantable Device for Atrial Therapy (2001)
    Oxford, UK : Blackwell Science Inc
    Journal of cardiovascular electrophysiology 12 (2001), S. 0 
    Details
    ISSN: 1540-8167
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Pacing for Treatment of Atrial Tachyarrhythmias. Introduction: Patients with bradycardia requiring permanent pacing frequently suffer from additional atrial tachyarrhythmias (ATs). This study evaluated the safety and efficacy of atrial antitachycardia pacing (ATP) and the performance of pacing for AT prevention implemented into a new pacemaker. Methods and Results: In patients with conventional indications for permanent pacing, an investigational DDDRP pacemaker (Medtronic AT500, model 7253) was implanted. The primary study objectives were to determine the safety of overall device functioning and its efficacy in terminating spontaneous AT. A secondary endpoint was to determine the reliability of AT detection. Pacemaker memory functions were used to analyze the impact of dedicated pacing algorithms on AT prevention. In 33 European and Canadian centers, 325 patients were enrolled (mean follow-up 2.3 ± 1.3 months). Complication-free survival at 3 months was 88%. In 2,145 episodes stored with atrial electrograms, AT detection was confirmed in 97%. The algorithm for continuous overdrive pacing increased the percentage of atrial pacing to 97%. After ATP activation, 16,683 of 52,468 AT episodes were treated (120 patients). Of these, 8,903 episodes (53%) were terminated successfully by ATP. No proarrhythmic effect of preventive pacing or atrial ATP was observed. Preventive pacing algorithms increased the median percentage of atrial pacing from 62% to 97%. However, the number of AT/AF (atrial fibrillation) episodes (4.1 vs 4.1 per patient per day) and the time in AT/AF (13.7% vs 12.8%) was not significantly different before and after activation of preventive pacing. Conclusion: DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1540-8167.2001.01121.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Coronary Artery Stenting in Vessels with Reference Diameter 〈 3 MM (2000)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of interventional cardiology 13 (2000), S. 0 
    Details
    ISSN: 1540-8183
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The study included 220 consecutive patients with coronary artery stenting. In 128 patients (60.8 ± 10.2 years, 68% men), a total of 184 stents were placed in coronary vessels with a reference diameter 〈 3 mm (group S). One hundred thirty-four stents were implanted in 92 patients (62.9 ± 9.8 years, 82.6% men) in vessels 〉 3 mm (group L). There was no significant difference according to clinical baseline characteristics. The primary end point of this retrospective study was the rate of periinterventional complications (death, stent thrombosis, myocardial infarction, urgent angioplasty, or surgical revascularization). The, secondary end point was the clinical and angiographic follow-ups (restenosis, recurrent angina, further revascularization) after 3 months. Cardiac complications occurred in group S in two (1.6%) patients, two stent thromboses with urgent angioplasty, one Q-wave and one non-Q-wave infarction. There was one (1.1%) event in group L, a stent thrombosis with Q-wave infarction and urgent angioplasty. Angiography at 3-month follow-up was performed in 148 patients. Restenosis occurred in group S in 31.8% and in group L in 21.7% (NS). Data according recurrent angina and recommended surgical revascularization did not differ between both groups. In group S, significantly more angioplasties of the stented lesion were performed (23/60 patients) compared to group L (6/88) (P = 0,015). Coronary artery stenting in vessels with a reference diameter 〈 3 mm can be performed without a high rate of periinterventional complications. Restenosis tends to be more frequent in the small vessel group, a higher rate of reangioplasties have to be expected. The clinical follow-up is comparable to a control group.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1540-8183.2000.tb00308.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Form Analysis Using Digital Signal Processing Reliably Discriminates Far-Field R Waves from P Waves (2004)
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Pacing and clinical electrophysiology 27 (2004), S. 0 
    Details
    ISSN: 1540-8159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The correct detection of atrial arrhythmias by pacemakers is often limited by the presence of far-field R waves (FFRWs) in the atrial electrogram. Digital signal processing (DSP) of intracardiac signals is assumed to provide improved discrimination between P waves and FFRWs when compared to current methods. For this purpose, 100 bipolar and unipolar intracardiac atrial recordings from 31 patients were collected during pacemaker replacement and used for the off-line application of a novel DSP algorithm. Digital processing of the atrial intracardiac electrogram (IEGM) signals (8 bit, 800 samples/s) included filtering and calculation of the maximum amplitude and slope of the detected events. The form parameter was calculated, being the sum of the most negative value of the amplitude and that of the slope of the detected event. The algorithm collects form parameter data of P waves and FFRWs and composes histograms of these data. A sufficiently large gap between the FFRW and P wave histograms allows discrimination of these two signals based on form parameters. Three independent observers reviewed the reliability of classification with this algorithm. Sensitivity and specificity of FFRW detection were 99.63% and 100%, respectively, and no P waves were falsely classified. It can be concluded that this novel DSP algorithm shows excellent discrimination of FFRWs under off-line conditions and justify the implementation of this algorithm in future pacemakers for real-time discrimination between P waves and FFRWs. This method prevents false mode switching and allows correct and immediate intervention pacing for atrial tachyarrhythmias.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1540-8159.2004.00694.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Hyperfibrinogenemia increases the risk of cardiac events after coronary artery stenting (2000)
    Springer
    Heart and vessels 15 (2000), S. 263-267 
    Details
    ISSN: 1615-2573
    Schlagwort(e): Key words Fibrinogen ; Coronary artery stenting ; Adverse cardiac events
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Primary success rates, and the angiographic and clinical outcome after percutaneous coronary intervention, are influenced by many different factors. Clinical features and morphologic characteristics of the target lesion are important. Also, interventionally caused endothelial trauma may trigger atherogenetic and procoagulatory factors leading to intraluminal thrombosis. The study population consisted of 228 consecutive, unselected patients with symptomatic coronary artery disease or exercise-induced myocardial ischemia and coronary artery stenoses eligible for percutaneous intervention. We analyzed different clinical, morphological, and laboratory (total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglycerides, fibrinogen) features in those patients with adverse cardiac events (stent thrombosis, myocardial infarction, urgent target vessel revascularization, death) after primary successful coronary artery stenting, compared with a control group without adverse events. In the group with adverse cardiac events we found a significantly higher level of fibrinogen compared with the control group. Other laboratory data and clinical characteristics were not significantly different between the two groups. The study shows a possible association between hyperfibrinogenemia and adverse cardiac events after intracoronary stenting. In clinical practice, the potential role of elevated levels of fibrinogen in an unfavorable outcome after percutaneous coronary interventions should be considered when planning coronary artery stenting.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003800070003
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...