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)

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)

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)

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%.

Although it has become standard practice to performelectrophysiologic studies in patients with unexplained syncope,limited information exists on prognosis after therapy guided byelectrophysiologic studies.

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.