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Maintenance of cavo-tricuspidal isthmus conduction block after radiofrequency ablation
Poster 4 during AF ablation to prevent atrio-esophageal fistula, in particular in view of the need for transmural atrial lesions.
S237 waves in V1 were positive in all patients with FLATs originating from PVs. Using the criterion that a positive P wave in V1 in patients with FLATs indicates a PV origin, resulted in a sensitivity of 100%, specificity of 78.6%, positive predictive accuracy of 80% and negative predictive accuracy of 100%. Negative P waves in aVL were always observed in FLATs originating from left PVs. The mean cycle length of FLATs from the PVs was significantly shorter than that from the MA (313.8 ⫾ 58.9 ms vs 366.8 ⫾ 57.2 ms, p⫽0.04). Conclusion: Knowledge of topographic distribution, P-wave morphology, and tachycardia cycle length facilitates successful ablation of FLATs.
P4-71 CRYO BALLOON ABLATION IN THE LEFT ATRIA AND ESOPHAGEAL INJURY Dinas Aleksonis, MD, Daniel Lafontaine, BS, Alexandru Chicos, MD, Andrew Mykytsey, MD and Boaz Avitall, MD, PhD. University of Illinois at Chicago, Chicago, IL. Esophagus to LA fistula formation is a devastating complication of LA RF circumferential ablation. It is proposed that cryo balloon ablation is a safer and more effective technology for the ablation of AF. In four dogs (35⫾2 Kg) we have examined the impact of cryo balloon ablation of both PVs and posterior LA tissues on the integrity of the esophagus. Total of 42 lesions were placed, at the average body temperature of 99⫾0.8 F, and average maximal catheter temperatures of -77⫾2 C that were applied for 2 min. The lowest average intra-esophageal temperatures of 94⫾1 F at the time of ablation were recorded by esophageal thermometer that was placed at the location of lowest temperature and closest proximity to the cryo balloon assessed by steep LAO and RAO fluoroscopy. Cryo ablations were applied above the mitral ring where the LA and the esophagus are in closest proximity. The lowest temperature was recorded during left inferior pulmonary veins and posterior LA wall ablation. Pathological evaluation of the external esophagus examined acutely and 1 week after ablation revealed circular hemorrhagic lesions in close proximity to each other with maximum diameter of 18.7 mm, with an elevated erythematous rim surrounding each lesion. Morphologically most lesions were in the serosa and the external muscular coat of the esophagus. All lesions were sectioned. Histologic evaluation documented loss of nuclei, loss of architecture and pyknosis of myocytes. In the 3-7 days old lesions, there was mild lymphocytic infiltration with damage involving the serosa, the external muscle layer and with mild focal damage to the inner muscle layer. Sub-mucosal glands and the mucosa were normal. Conclusion: Cryo balloon ablation of the inferior PVs and the posterior wall of the LA in this model does penetrate to the outer layers of the esophagus, however no transmural lesions were noted and esophagus structural integrity remained intact.
P4-73 MAINTENANCE OF CAVO-TRICUSPIDAL ISTHMUS CONDUCTION BLOCK AFTER RADIOFREQUENCY ABLATION Elena Lucca, MD, Nikolos Bakthadze, MD, Carlo Ceriotti, MD and Marco Zardini, MD, PhD. Humanitas Gavazzeni Hospital, Bergamo, Italy. Inferior cavo-tricuspid isthmus (CTI) block is the success marker of typical atrial flutter (AFl) ablation (RFA). However, limited information is available on the long-term persistence of CTI block in patients (pts) with no clinical recurrences. The aim of our study was to assess the chronic efficacy of RFA of the CTI and to identify parameters associated with recurrences of conduction. Methods: Out of 92 consecutive pts who underwent RFA with 8-mm tip catheters over the last 4 years, a late control EP study was initially performed in 29 pts at a median of 2 months, independently from the presence of symptoms. RFA was performed with discrete pulses at 100watt output and 65°C temperature. Standard criteria were used to define complete CTI block. RFA was repeated in all pts with recurrent CTI conduction. Results: Complete CTI block was acutely obtained in all pts. At the control study, only 1 pt had had a documented AFl recurrence. The CTI conduction recovered in 8/29 (27%), while in 21 pts the block was persistent. The 2 groups did not differ in terms of BSA (1.96 vs 1.87 mq), LVEF (60% vs 55%), arrhythmia duration (24 vs 18 months) and drug therapy. The differences regarded the number of RF applications (30⫾15 vs 17⫾8, p⫽0.007) and total burn time (805⫾421 vs 398⫾185 sec, p⫽0.001). Over a subsequent follow-up of 19 months, typical AFL recurred in 1 pt. Conclusions: Late recovery of CTI conduction occurs in a high percentage of asymptomatic pts after successful AFl RFA and is correlated with the amount of energy delivered, suggesting that conformation and dimensions of the CTI may be involved. We suggest a control EP study when longer burn times were required to achieve block, even in asymptomatic pts.
P4-72
P4-74
TOPOGRAPHIC DISTRIBUTION OF FOCAL LEFT ATRIAL TACHYCARDIAS DEFINED BY ELECTROCARDIOGRAPHIC AND ELECTROPHYSIOLOGICAL DATA Hitoshi Hachiya, MD, Yoshito Iesaka, MD, Sabine Ernst, MD, Feifan Ouyang, MD, Matthias Antz, MD and Karl-Heinz Kuck, MD. Tsuchiura Kyodo Hospital, Tsuchiura, Japan and II. Med. Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany.
PAROXYSMAL PATTERN OF ATRIAL FLUTTER PREDICTS NONISTHMUS DEPENDENCY IN PATIENTS REFERRED FOR CATHETER ABLATION OF ATRIAL FLUTTER Lars M. Lickfett, MD, Hugh Calkins, MD, Khurram Nasir, Timm-Michael Dickfeld, MD, PhD, Zayd Eldadah, Vinod Jayam, Charles Leng, Gordon Tomaselli, MD, J. Kevin Donahue, Henry R. Halperin, MD, Berndt Lu¨deritz, MD and Ronald Berger. University of Bonn, Bonn, Germany, Johns Hopkins University, Baltimore, MD, Johns Hopkins University, MD and University of Bonn, Germany.
Background: There is limited data about detailed topographic distribution of focal left atrial tachycardias (FLATs). Methods and Results: A total of 143 atrial tachycardia (AT) foci were successfully ablated in 140 patients (56 men, mean age 44.6 ⫾ 17.9 years). In 36.4% (52/143 ATs), a left atrial (LA) origin of the tachycardia was identified by the site of successful ablation. In 46% (24/52) of FLATs, the site of origin (SO) was located near the ostium of a pulmonary vein (PV), and in 36.5% (19/52), the SO was located near the mitral annulus (MA). In the remaining ATs, the SO was located in the left atrial appendage (LAA), septum, LA roof and inside the coronary sinus. P waves in V1 showed biphasic morphology with an initial negative component in most FLATs originating from the septal MA, superior MA, and LAA. However, P
Background: Typical atrial flutter (AFL) can be cured by catheter ablation of the right atrial cavotricuspid isthmus (CTI). The surface ECG is not always diagnostic of isthmus dependence of AFL. The goal of the present study was to evaluate clinical characteristics for prediction of isthmus dependent AFL. Methods: 61 patients (pts) referred for catheter ablation of AFL were included. Pts with previous AFL ablation or congenital heart disease were excluded. All patients had distinct flutter waves in the inferior leads, suggestive of right atrial isthmus dependent AFL, either on presentation to the EP lab or documented on prior ECG. Pts who presented to the EP lab
S237 waves in V1 were positive in all patients with FLATs originating from PVs. Using the criterion that a positive P wave in V1 in patients with FLATs indicates a PV origin, resulted in a sensitivity of 100%, specificity of 78.6%, positive predictive accuracy of 80% and negative predictive accuracy of 100%. Negative P waves in aVL were always observed in FLATs originating from left PVs. The mean cycle length of FLATs from the PVs was significantly shorter than that from the MA (313.8 ⫾ 58.9 ms vs 366.8 ⫾ 57.2 ms, p⫽0.04). Conclusion: Knowledge of topographic distribution, P-wave morphology, and tachycardia cycle length facilitates successful ablation of FLATs.
P4-71 CRYO BALLOON ABLATION IN THE LEFT ATRIA AND ESOPHAGEAL INJURY Dinas Aleksonis, MD, Daniel Lafontaine, BS, Alexandru Chicos, MD, Andrew Mykytsey, MD and Boaz Avitall, MD, PhD. University of Illinois at Chicago, Chicago, IL. Esophagus to LA fistula formation is a devastating complication of LA RF circumferential ablation. It is proposed that cryo balloon ablation is a safer and more effective technology for the ablation of AF. In four dogs (35⫾2 Kg) we have examined the impact of cryo balloon ablation of both PVs and posterior LA tissues on the integrity of the esophagus. Total of 42 lesions were placed, at the average body temperature of 99⫾0.8 F, and average maximal catheter temperatures of -77⫾2 C that were applied for 2 min. The lowest average intra-esophageal temperatures of 94⫾1 F at the time of ablation were recorded by esophageal thermometer that was placed at the location of lowest temperature and closest proximity to the cryo balloon assessed by steep LAO and RAO fluoroscopy. Cryo ablations were applied above the mitral ring where the LA and the esophagus are in closest proximity. The lowest temperature was recorded during left inferior pulmonary veins and posterior LA wall ablation. Pathological evaluation of the external esophagus examined acutely and 1 week after ablation revealed circular hemorrhagic lesions in close proximity to each other with maximum diameter of 18.7 mm, with an elevated erythematous rim surrounding each lesion. Morphologically most lesions were in the serosa and the external muscular coat of the esophagus. All lesions were sectioned. Histologic evaluation documented loss of nuclei, loss of architecture and pyknosis of myocytes. In the 3-7 days old lesions, there was mild lymphocytic infiltration with damage involving the serosa, the external muscle layer and with mild focal damage to the inner muscle layer. Sub-mucosal glands and the mucosa were normal. Conclusion: Cryo balloon ablation of the inferior PVs and the posterior wall of the LA in this model does penetrate to the outer layers of the esophagus, however no transmural lesions were noted and esophagus structural integrity remained intact.
P4-73 MAINTENANCE OF CAVO-TRICUSPIDAL ISTHMUS CONDUCTION BLOCK AFTER RADIOFREQUENCY ABLATION Elena Lucca, MD, Nikolos Bakthadze, MD, Carlo Ceriotti, MD and Marco Zardini, MD, PhD. Humanitas Gavazzeni Hospital, Bergamo, Italy. Inferior cavo-tricuspid isthmus (CTI) block is the success marker of typical atrial flutter (AFl) ablation (RFA). However, limited information is available on the long-term persistence of CTI block in patients (pts) with no clinical recurrences. The aim of our study was to assess the chronic efficacy of RFA of the CTI and to identify parameters associated with recurrences of conduction. Methods: Out of 92 consecutive pts who underwent RFA with 8-mm tip catheters over the last 4 years, a late control EP study was initially performed in 29 pts at a median of 2 months, independently from the presence of symptoms. RFA was performed with discrete pulses at 100watt output and 65°C temperature. Standard criteria were used to define complete CTI block. RFA was repeated in all pts with recurrent CTI conduction. Results: Complete CTI block was acutely obtained in all pts. At the control study, only 1 pt had had a documented AFl recurrence. The CTI conduction recovered in 8/29 (27%), while in 21 pts the block was persistent. The 2 groups did not differ in terms of BSA (1.96 vs 1.87 mq), LVEF (60% vs 55%), arrhythmia duration (24 vs 18 months) and drug therapy. The differences regarded the number of RF applications (30⫾15 vs 17⫾8, p⫽0.007) and total burn time (805⫾421 vs 398⫾185 sec, p⫽0.001). Over a subsequent follow-up of 19 months, typical AFL recurred in 1 pt. Conclusions: Late recovery of CTI conduction occurs in a high percentage of asymptomatic pts after successful AFl RFA and is correlated with the amount of energy delivered, suggesting that conformation and dimensions of the CTI may be involved. We suggest a control EP study when longer burn times were required to achieve block, even in asymptomatic pts.
P4-72
P4-74
TOPOGRAPHIC DISTRIBUTION OF FOCAL LEFT ATRIAL TACHYCARDIAS DEFINED BY ELECTROCARDIOGRAPHIC AND ELECTROPHYSIOLOGICAL DATA Hitoshi Hachiya, MD, Yoshito Iesaka, MD, Sabine Ernst, MD, Feifan Ouyang, MD, Matthias Antz, MD and Karl-Heinz Kuck, MD. Tsuchiura Kyodo Hospital, Tsuchiura, Japan and II. Med. Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany.
PAROXYSMAL PATTERN OF ATRIAL FLUTTER PREDICTS NONISTHMUS DEPENDENCY IN PATIENTS REFERRED FOR CATHETER ABLATION OF ATRIAL FLUTTER Lars M. Lickfett, MD, Hugh Calkins, MD, Khurram Nasir, Timm-Michael Dickfeld, MD, PhD, Zayd Eldadah, Vinod Jayam, Charles Leng, Gordon Tomaselli, MD, J. Kevin Donahue, Henry R. Halperin, MD, Berndt Lu¨deritz, MD and Ronald Berger. University of Bonn, Bonn, Germany, Johns Hopkins University, Baltimore, MD, Johns Hopkins University, MD and University of Bonn, Germany.
Background: There is limited data about detailed topographic distribution of focal left atrial tachycardias (FLATs). Methods and Results: A total of 143 atrial tachycardia (AT) foci were successfully ablated in 140 patients (56 men, mean age 44.6 ⫾ 17.9 years). In 36.4% (52/143 ATs), a left atrial (LA) origin of the tachycardia was identified by the site of successful ablation. In 46% (24/52) of FLATs, the site of origin (SO) was located near the ostium of a pulmonary vein (PV), and in 36.5% (19/52), the SO was located near the mitral annulus (MA). In the remaining ATs, the SO was located in the left atrial appendage (LAA), septum, LA roof and inside the coronary sinus. P waves in V1 showed biphasic morphology with an initial negative component in most FLATs originating from the septal MA, superior MA, and LAA. However, P
Background: Typical atrial flutter (AFL) can be cured by catheter ablation of the right atrial cavotricuspid isthmus (CTI). The surface ECG is not always diagnostic of isthmus dependence of AFL. The goal of the present study was to evaluate clinical characteristics for prediction of isthmus dependent AFL. Methods: 61 patients (pts) referred for catheter ablation of AFL were included. Pts with previous AFL ablation or congenital heart disease were excluded. All patients had distinct flutter waves in the inferior leads, suggestive of right atrial isthmus dependent AFL, either on presentation to the EP lab or documented on prior ECG. Pts who presented to the EP lab