OBJECTIVES: The goal of this study was to characterize the origin of focal atrial tachycardias (AT). BACKGROUND: Focal ATs originate from a small area and spread centrifugally; however, activation at the AT origin has not been characterized. METHODS: Twenty patients with AT having failed prior ablation or occurring after atrial fibrillation ablation were studied. After excluding macro-re-entry, AT was mapped using a 20-pole catheter (five radiating spines; diameter 3.5 cm), performing vector mapping to identify the earliest activity followed by high-density mapping at the AT origin. Localized re-entry was considered if >85% of the tachycardia cycle length (CL) was observed within the mapping field and was confirmed by entrainment. RESULTS: A total of 27 ATs were mapped to the pulmonary vein ostia (n = 5), and left (n = 16) and right atria (n = 6). A localized focus was evidenced at the site of origin in 19 ATs (70%), whereas in 8 (30%), localized re-entry was evidenced by 95.2 +/- 4.5% of the tachycardia CL recorded within the mapping field and entrainment showed a post-pacing interval <20 ms longer than tachycardia CL (6 of 6 tested). Localized re-entry had a shorter CL (p = 0.009), slowed conduction at its origin (fractionated potential 115 +/- 19 ms vs. 64 +/- 22 ms, representing 49 +/- 10% and 20 +/- 10% of tachycardia CL, respectively; p < 0.0001), and were more often contiguous with regions of electrical silence or conduction abnormalities (88% vs. 32%; p = 0.01). In addition, mapping documented varying degrees of intra-atrial conduction block, preferential conduction (n = 5), and rapid bursts of myocardial activity (n = 1). At 11 +/- 7 months, none have had recurrence of AT. CONCLUSIONS: High-density multielectrode mapping can be used to perform vector mapping to localize complex AT. It provides novel insight into the mechanisms of focal AT, distinguishing focal AT from localized re-entry.
OBJECTIVES: The goal of this study was to characterize the origin of focal atrial tachycardias (AT). BACKGROUND: Focal ATs originate from a small area and spread centrifugally; however, activation at the AT origin has not been characterized. METHODS: Twenty patients with AT having failed prior ablation or occurring after atrial fibrillation ablation were studied. After excluding macro-re-entry, AT was mapped using a 20-pole catheter (five radiating spines; diameter 3.5 cm), performing vector mapping to identify the earliest activity followed by high-density mapping at the AT origin. Localized re-entry was considered if >85% of the tachycardia cycle length (CL) was observed within the mapping field and was confirmed by entrainment. RESULTS: A total of 27 ATs were mapped to the pulmonary vein ostia (n = 5), and left (n = 16) and right atria (n = 6). A localized focus was evidenced at the site of origin in 19 ATs (70%), whereas in 8 (30%), localized re-entry was evidenced by 95.2 +/- 4.5% of the tachycardia CL recorded within the mapping field and entrainment showed a post-pacing interval <20 ms longer than tachycardia CL (6 of 6 tested). Localized re-entry had a shorter CL (p = 0.009), slowed conduction at its origin (fractionated potential 115 +/- 19 ms vs. 64 +/- 22 ms, representing 49 +/- 10% and 20 +/- 10% of tachycardia CL, respectively; p < 0.0001), and were more often contiguous with regions of electrical silence or conduction abnormalities (88% vs. 32%; p = 0.01). In addition, mapping documented varying degrees of intra-atrial conduction block, preferential conduction (n = 5), and rapid bursts of myocardial activity (n = 1). At 11 +/- 7 months, none have had recurrence of AT. CONCLUSIONS: High-density multielectrode mapping can be used to perform vector mapping to localize complex AT. It provides novel insight into the mechanisms of focal AT, distinguishing focal AT from localized re-entry.
Authors: Leon M Ptaszek; Fadi Chalhoub; Francesco Perna; Roy Beinart; Conor D Barrett; Stephan B Danik; E Kevin Heist; Jeremy N Ruskin; Moussa Mansour Journal: J Interv Card Electrophysiol Date: 2012-11-22 Impact factor: 1.900
Authors: Isabelle Nault; Nicolas Lellouche; Seiichiro Matsuo; Sébastien Knecht; Matthew Wright; Kang-Teng Lim; Frederic Sacher; Pyotr Platonov; Antoine Deplagne; Pierre Bordachar; Nicolas Derval; Mark D O'Neill; George J Klein; Mélèze Hocini; Pierre Jaïs; Jacques Clémenty; Michel Haïssaguerre Journal: J Interv Card Electrophysiol Date: 2009-04-30 Impact factor: 1.900