BACKGROUND: Complete electrical isolation of pulmonary veins (PVs) remains the cornerstone of ablation therapy for atrial fibrillation. Entrance block without exit block has been reported to occur in 40% of the patients. Far-field capture (FFC) can occur during pacing from the superior PVs to assess exit block, and this may appear as persistent conduction from PV to left atrium (LA). OBJECTIVE: To facilitate accurate assessment of exit block. METHODS: Twenty consecutive patients with symptomatic atrial fibrillation referred for ablation were included in the study. Once PV isolation (entrance block) was confirmed, pacing from all the bipoles on the Lasso catheter was used to assess exit block by using a pacing stimulus of 10 mA at 2 ms. Evidence for PV capture without conduction to LA was necessary to prove exit block. If conduction to LA was noticed, pacing output was decreased until there was PV capture without conduction to LA or no PV capture was noted to assess for far-field capture in both the upper PVs. RESULTS: All 20 patients underwent successful isolation (entrance block) of all 76 (4 left common PV) veins: mean age 58 ± 9 years; paroxysmal atrial fibrillation 40%; hypertension 70%, diabetes mellitus 30%, coronary artery disease 15%; left ventricular ejection fraction 55% ± 10%; LA size 42 ± 11 mm. Despite entrance block, exit block was absent in only 16% of the PVs, suggesting persistent PV to LA conduction. FFC of LA appendage was noted in 38% of the left superior PVs. FFC of the superior vena cava was noted in 30% of the right superior PVs. The mean pacing threshold for FFC was 7 ± 4 mA. Decreasing pacing output until only PV capture (loss of FFC) is noted was essential to confirm true exit block. CONCLUSIONS: FFC of LA appendage or superior vena cava can masquerade as persistent PV to LA conduction. A careful assessment for PV capture at decreasing pacing output is essential to exclude FFC.
BACKGROUND: Complete electrical isolation of pulmonary veins (PVs) remains the cornerstone of ablation therapy for atrial fibrillation. Entrance block without exit block has been reported to occur in 40% of the patients. Far-field capture (FFC) can occur during pacing from the superior PVs to assess exit block, and this may appear as persistent conduction from PV to left atrium (LA). OBJECTIVE: To facilitate accurate assessment of exit block. METHODS: Twenty consecutive patients with symptomatic atrial fibrillation referred for ablation were included in the study. Once PV isolation (entrance block) was confirmed, pacing from all the bipoles on the Lasso catheter was used to assess exit block by using a pacing stimulus of 10 mA at 2 ms. Evidence for PV capture without conduction to LA was necessary to prove exit block. If conduction to LA was noticed, pacing output was decreased until there was PV capture without conduction to LA or no PV capture was noted to assess for far-field capture in both the upper PVs. RESULTS: All 20 patients underwent successful isolation (entrance block) of all 76 (4 left common PV) veins: mean age 58 ± 9 years; paroxysmal atrial fibrillation 40%; hypertension 70%, diabetes mellitus 30%, coronary artery disease 15%; left ventricular ejection fraction 55% ± 10%; LA size 42 ± 11 mm. Despite entrance block, exit block was absent in only 16% of the PVs, suggesting persistent PV to LA conduction. FFC of LA appendage was noted in 38% of the left superior PVs. FFC of the superior vena cava was noted in 30% of the right superior PVs. The mean pacing threshold for FFC was 7 ± 4 mA. Decreasing pacing output until only PV capture (loss of FFC) is noted was essential to confirm true exit block. CONCLUSIONS: FFC of LA appendage or superior vena cava can masquerade as persistent PV to LA conduction. A careful assessment for PV capture at decreasing pacing output is essential to exclude FFC.
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: Heart Rhythm Date: 2017-05-12 Impact factor: 6.343
Authors: Hugh Calkins; Karl Heinz Kuck; Riccardo Cappato; Josep Brugada; A John Camm; Shih-Ann Chen; Harry J G Crijns; Ralph J Damiano; D Wyn Davies; John DiMarco; James Edgerton; Kenneth Ellenbogen; Michael D Ezekowitz; David E Haines; Michel Haissaguerre; Gerhard Hindricks; Yoshito Iesaka; Warren Jackman; José Jalife; Pierre Jais; Jonathan Kalman; David Keane; Young-Hoon Kim; Paulus Kirchhof; George Klein; Hans Kottkamp; Koichiro Kumagai; Bruce D Lindsay; Moussa Mansour; Francis E Marchlinski; Patrick M McCarthy; J Lluis Mont; Fred Morady; Koonlawee Nademanee; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Douglas L Packer; Carlo Pappone; Eric Prystowsky; Antonio Raviele; Vivek Reddy; Jeremy N Ruskin; Richard J Shemin; Hsuan-Ming Tsao; David Wilber Journal: Heart Rhythm Date: 2012-03-01 Impact factor: 6.343
Authors: Dirk Vollmann; Lars Lüthje; Joachim Seegers; Christian Sohns; Samuel Sossalla; Jan Sohns; Christian Röver; Gerd Hasenfuß; Markus Zabel Journal: J Interv Card Electrophysiol Date: 2014-06-04 Impact factor: 1.900
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: Europace Date: 2018-01-01 Impact factor: 5.214
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: J Interv Card Electrophysiol Date: 2017-10 Impact factor: 1.900
Authors: Hugh Calkins; Gerhard Hindricks; Riccardo Cappato; Young-Hoon Kim; Eduardo B Saad; Luis Aguinaga; Joseph G Akar; Vinay Badhwar; Josep Brugada; John Camm; Peng-Sheng Chen; Shih-Ann Chen; Mina K Chung; Jens Cosedis Nielsen; Anne B Curtis; D Wyn Davies; John D Day; André d'Avila; N M S Natasja de Groot; Luigi Di Biase; Mattias Duytschaever; James R Edgerton; Kenneth A Ellenbogen; Patrick T Ellinor; Sabine Ernst; Guilherme Fenelon; Edward P Gerstenfeld; David E Haines; Michel Haissaguerre; Robert H Helm; Elaine Hylek; Warren M Jackman; Jose Jalife; Jonathan M Kalman; Josef Kautzner; Hans Kottkamp; Karl Heinz Kuck; Koichiro Kumagai; Richard Lee; Thorsten Lewalter; Bruce D Lindsay; Laurent Macle; Moussa Mansour; Francis E Marchlinski; Gregory F Michaud; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Ken Okumura; Douglas Packer; Evgeny Pokushalov; Matthew R Reynolds; Prashanthan Sanders; Mauricio Scanavacca; Richard Schilling; Claudio Tondo; Hsuan-Ming Tsao; Atul Verma; David J Wilber; Teiichi Yamane Journal: J Arrhythm Date: 2017-09-15