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ABSTRACT: SEIDL, K., et al.: Catheter Ablation of Chronic Atrial Fibrillation with Noncontact Mapping: Are Continuous Linear Lesions Associated with Ablation Success?Catheter-based, right and left atrial compartmentalization procedure was evaluated using a noncontact mapping (NCM) system. Its usefulness to identify and close discontinuities in linear lesions in both atria was evaluated. The impact of linear lesion continuity on ablation success of chronic AF was also investigated. Nineteen patients with symptomatic, drug refractory chronic AF were studied. Right atrial ablation with three predefined lines was attempted in all patients. In 18 patients, left atrial ablation was performed with four linear lesions. During a follow-up of 12 ± 3 months, 6 of 19 patients remained in sinus rhythm (SR) without antiarrhythmic agents (AAs). In addition, four patients were maintained in SR with AA. Thirteen of 14 patients with gaps identified during off-line analysis had recurrence of AF. Only one patient with a gap was free of recurrence without AAs. In the remaining five patients without recurrence of AF, no gap was observed during off-line analysis. In all four patients who were free of AF with additional treatment of AAs, two gaps had been identified. In the remaining nine patients with chronic AF recurrence, a mean of 4.9 gaps were identified. Excluding the initial learning period (first five patients) the success rate increased to 43% (6/14 patients) without and to 71% (10/14 patients) with AA. NCM identifies discontinuities in lines of ablation. Successful ablation of chronic AF is associated with continuity of linear lesions and good clinical technique demands a vigilant search for and closure of every gap. (PACE 2003; 26[Pt. I]:534–543)
Pacing and Clinical Electrophysiology 03/2003; 26(2p1):534 - 543. · 1.35 Impact Factor
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ABSTRACT: SEIDL, K., et al.: Noncontact Mapping of Ectopic Atrial Tachycardias: Different Characteristics of Isopotential Maps and Unipolar Electrogram.The success rate for catheter ablation of ectopic atrial tachycardia (AT) has been limited by the inherent difficulty in localizing the site of origin within the complex three-dimensional structures of the atria. The objective of the study was to determine the usefulness of a noncontact mapping system for catheter ablation of AT. Radiofrequency ablation of 25 ATs was performed using a noncontact mapping system. Three different characteristics of isopotential maps and unipolar electrogram morphologies were observed: Group 1: Isopotential maps displayed a narrow, sharp ring of colors around a white, center spot. Unipolar electrograms revealed a Q-S morphology with a rapid dV/dt. Group 2: Isopotential maps displayed a broad ring of colors with little or no white spot in the center. Unipolar electrograms revealed a low amplitude, broad and smooth Q-S morphology in front of a second component with a rapid dV/dt. Group 3: Isopotential maps displayed a broad ring of colors. Unipolar electrogams revealed a low amplitude and fractionated waveform followed by endocardial breakthrough with a gradual dV/dt. Radiofrequency catheter ablation was successful in all ATs of groups 1 and 2, and failed in two of three ATs in group 3. The overall success rate was 92%. No severe complications were observed. Noncontact isopotential mapping is helpful to identify and characterize the origin of ectopic AT. Ablation success is associated with the characteristics of isopotential maps and unipolar electrogram morphologies. The overall success rate was 92%. (PACE 2003; 26[Pt. I]:16–25)
Pacing and Clinical Electrophysiology 03/2003; 26(1p1):16 - 25. · 1.35 Impact Factor
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ABSTRACT: Catheter-based, right and left atrial compartmentalization procedure was evaluated using a noncontact mapping (NCM) system. Its usefulness to identify and close discontinuities in linear lesions in both atria was evaluated. The impact of linear lesion continuity on ablation success of chronic AF was also investigated. Nineteen patients with symptomatic, drug refractory chronic AF were studied. Right atrial ablation with three predefined lines was attempted in all patients. In 18 patients, left atrial ablation was performed with four linear lesions. During a follow-up of 12 +/- 3 months, 6 of 19 patients remained in sinus rhythm (SR) without antiarrhythmic agents (AAs). In addition, four patients were maintained in SR with AA. Thirteen of 14 patients with gaps identified during off-line analysis had recurrence of AF. Only one patient with a gap was free of recurrence without AAs. In the remaining five patients without recurrence of AF, no gap was observed during off-line analysis. In all four patients who were free of AF with additional treatment of AAs, two gaps had been identified. In the remaining nine patients with chronic AF recurrence, a mean of 4.9 gaps were identified. Excluding the initial learning period (first five patients) the success rate increased to 43% (6/14 patients) without and to 71% (10/14 patients) with AA. NCM identifies discontinuities in lines of ablation. Successful ablation of chronic AF is associated with continuity of linear lesions and good clinical technique demands a vigilant search for and closure of every gap.
Pacing and Clinical Electrophysiology 03/2003; 26(2 Pt 1):534-43. · 1.35 Impact Factor
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ABSTRACT: The success rate for catheter ablation of ectopic atrial tachycardia (AT) has been limited by the inherent difficulty in localizing the site of origin within the complex three-dimensional structures of the atria. The objective of the study was to determine the usefulness of a noncontact mapping system for catheter ablation of AT. Radiofrequency ablation of 25 ATs was performed using a noncontact mapping system. Three different characteristics of isopotential maps and unipolar electrogram morphologies were observed: Group 1: Isopotential maps displayed a narrow, sharp ring of colors around a white, center spot. Unipolar electrograms revealed a Q-S morphology with a rapid dV/dt. Group 2: Isopotential maps displayed a broad ring of colors with little or no white spot in the center. Unipolar electrograms revealed a low amplitude, broad and smooth Q-S morphology in front of a second component with a rapid dV/dt. Group 3: Isopotential maps displayed a broad ring of colors. Unipolar electrogams revealed a low amplitude and fractionated waveform followed by endocardial breakthrough with a gradual dV/dt. Radiofrequency catheter ablation was successful in all ATs of groups 1 and 2, and failed in two of three ATs in group 3. The overall success rate was 92%. No severe complications were observed. Noncontact isopotential mapping is helpful to identify and characterize the origin of ectopic AT. Ablation success is associated with the characteristics of isopotential maps and unipolar electrogram morphologies. The overall success rate was 92%.
Pacing and Clinical Electrophysiology 02/2003; 26(1 Pt 1):16-25. · 1.35 Impact Factor
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ABSTRACT: Zusammenfassung. Hintergrund: Eine elektrophysiologische Untersuchung ist eine ntzliche Methode zur Ursachenabklrung bei nichtinvasiv ungeklrter Synkope bei 18-60% der Patienten. Auf der anderen Seite ist dieses eine invasive Methode und birgt ein Komplikationsrisiko. Daher sollten Patienten identifiziert werden, bei denen eine EPU sinnvoll zur Diagnosefindung beitrgt. Methoden: Patienten mit unerklrter Synkope wurden prospektiv in einem Register eingeschlossen, wenn eine elektrophysiologische Untersuchung durchgefhrt wurde. Die Studienpopulation bestand aus 643 konsekutiven Patienten. Ergebnisse: Die elektrophysiologischen Untersuchungen zeigten bei 35% der Patienten Leitungsstrungen bzw. Tachyarrhythmien als Ursache der Synkopen. Durch Einsatz eines logistischen Regressionsmodells wurde folgende unabhngige Prdiktoren fr eine pathologische elektrophysiologische Untersuchung identifiziert: Anamnese einer Verletzungsfolge (p<0,001), EF⣈% (p=0,03) und PR-Intervall >0,2s (p=0,001). Diese 3 einfach zu bestimmenden Variablen wurden in ein Score-System eingesetzt. Der maximale Score betrug 3 Punkte. Ein Score >1 sagt bei Patienten mit nichtinvasiv unerklrter Synkope eine positive elektrophysiologische Untersuchung in mehr als 70% voraus. Schlussfolgerung: Elektrophysiologische Aufflligkeiten wurden bei 35% der Patienten mit nicht invasiv unerklrter Synkope gefunden. Eine Verletzungsfolge in der Anamnese, EF⣈% und ein PR Intervall >200 ms waren unabhngige Faktoren fr eine positive elektrophysiologische Untersuchung. Summary. Background: An electrophysiologic study is a useful method to clarify the cause of non-invasively unexplained syncope in 18-60% of patients. However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope. Methods: Patients with unexplained syncope were prospectively enrolled in a registry, if an electrophysiologic study was performed. The study group comprised of 643 consecutive patients. Results: The electrophysiologic study revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. Using a logistic regression model, history of injury during syncope (p<0.001), ejection fraction ⣈% (p=0.03), and PR interval >0.2 s (p=0.001) were independent predictors of an abnormal electrophysiologic study. These three clinical and easily measurable variables were entered into a scoring system. The maximal score consisted of 3 points. A score of >1 predicts a positive electrophysiologic study result in more than 70% of patients with non-invasively unexplained syncope. Conclusion: Electrophysiologic abnormalities were detected in 35% of patients with unexplained syncope. A history of injury, ejection fraction ⣈% and a PR interval >200ms were independent predictors for a positive electrophysiologic study.
Zeitschrift für Kardiologie 01/2003; 92(2):147-154. · 0.97 Impact Factor
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ABSTRACT: The primary objective was to evaluate the usefulness of transesophageal echocardiography (TEE)-guided cardioversion to prevent thromboembolic complications in patients with atrial fibrillation (AF) and effective anticoagulation (International Normalized Ratio of 2 or 3) at least three weeks before cardioversion.
Transesophageal echocardiography has been proposed as a method of screening patients for left atrial thrombi before direct-current cardioversion of AF. The usefulness of TEE as a screening tool has always been evaluated in patients without long-term anticoagulation before cardioversion.
This prospective, single-center, observational study, performed on an intention-to-cardiovert basis, comprised 1,076 consecutive, unselected patients with AF. The initial two years were designed to be the control phase, during which the conventional approach was used. After that, cardioversion guided by TEE was performed in consecutive patients.
The prevalence of left atrial thrombi was 7.7% in patients with persistent AF and effective anticoagulation. During the first four weeks after electrical cardioversion, six thromboembolic complications were observed in patients in whom the TEE-guided approach was employed (6 [0.8%] of 719 patients), compared with three thromboembolic complications in patients in whom the conventional approach was used (3 [0.8%] of 357 patients). None of the patients in whom electrical cardioversion was not performed experienced an embolic event.
There were no differences in the rate of embolic events between the two treatment groups. In patients with AF and effective anticoagulation, TEE-guided electrical cardioversion does not reduce the embolic risk. However, TEE revealed left atrial thrombi in 7.7% of patients with AF and effective anticoagulation, before direct-current cardioversion.
Journal of the American College of Cardiology 06/2002; 39(9):1436-42. · 14.16 Impact Factor
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ABSTRACT: Congestive heart failure afflicts 2 to 4 million people in the US and nearly 15 million people worldwide. Accepted goals of heart failure treatment include: improvement of symptoms;prevention of disease progression; and reduction in morbidity and mortality. Complex pharmacological therapies achieve these goals, but not in all patients with heart failure. Cardiac resynchronization therapy (CRT) represents a new therapeutic approach in patients with chronic heart failure. CRT is only applicable to a subgroup of patients with ventricular conduction system delay, characterized by prolonged QRS duration. Bundle branch block impacts 20 to 30% of patients with New York Heart Association (NYHA) functional class III-IV heart failure and consists predominantly of left bundle branch block. When left ventricular (LV) conduction delay is superimposed upon ventricular dysfunction, it appears to be a marker of disease severity. These conduction abnormalities have deleterious effects both on systolic function and LV filling, and they can induce or enhance mitral functional regurgitation. CRT attempts to correct the deleterious effect of dysynchrony by increasing LV filling time, decreasing septal dyskinesis and reducing mitral regurgitation. Several observational studies and randomized, controlled trials have shown the benefit of CRT in a subgroup of patients with heart failure, with conduction delays. Improvements were found in the mean distance walked in 6 minutes, quality of life (QOL), NYHA functional class, in peak oxygen uptake (V-dot(2)), total exercise time, reduction of hospitalization, LV function and reduction of the LV end-diastolic diameter. These studies support the therapeutic value of ventricular resynchronization in patients with severe heart failure, who have intraventricular conduction delay but who do not have a standard indication for the implantation of a pacemaker. In respect to these study results, possible indications for a biventricular pacing device at this time are as follows: NYHA functional class III, LV ejection fraction <35%, sinus rhythm, QRS duration >150 msec and drug refractory despite individual optimal heart failure therapy. CRT significantly improved symptoms, exercise tolerance and QOL in most patients. However, further studies are needed to assess long-term clinical effects and prognosis, as well as economic benefit of this therapeutic approach.
American Journal of Cardiovascular Drugs 02/2002; 2(4):219-26. · 1.77 Impact Factor
