***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION Dormant pulmonary vein ( PV ) conduction can be provoked by adenosine triphosphate ( ATP ) after extensive encircling pulmonary vein isolation ( EEPVI ) . However , the clinical implication of reconnection between the left atrium ( LA ) and isolated PVs provoked by ATP ( ATP-reconnection ) remains unknown . METHODS AND RESULTS We studied the clinical consequences of ATP-reconnection during intravenous isoproterenol infusion ( ISP-infusion ) . EEPVI severs conduction between the LA and ipsilateral PVs at their junction . Radiofrequency energy is applied at a distance from the PV ostia guided by double Lasso catheters placed within the ipsilateral superior and inferior PVs . This study comprised 82 patients ( 67 men , 56 + /- 9 years old ) with atrial fibrillation ( AF ) who underwent injection of ATP during ISP infusion after successful EEPVI ( ATP(+ ) group ) . We compared clinical characteristics of 170 patients who underwent earlier EEPVI prior to our use of ATP injection after successful EEPVI ( ATP(N/D ) group ) with those of ATP(+ ) group patients who underwent one session of EEPVI .  ATP-reconnection occurred in 34 ( 41 % ) of 82 ATP(+ ) group patients . Additional radiofrequency applications were performed to eliminate ATP-reconnection in all ipsilateral PVs . Continuous ATP-reconnection of more than 20 seconds duration occurred in six ( 7.3 % ) of 82 patients . A total of 102 ( 60 % ) of 170 patients in the ATP(N/D ) group had no recurrence of AF , whereas 60 ( 73 % ) of 82 ATP(+ ) group patients who underwent only one EEPVI session have had no recurrence of AF in a 6.1 + /- 3.3-month follow-up period ( P = 0.04 ) . CONCLUSION Radiofrequency application for provoked ATP-reconnection may reduce clinical AF recurrence BACKGROUND Catheter ablation ( CA ) by wide encirclement of pulmonary veins ( WEPV ) restores sinus rhythm in up to 95 % . Complex PV-left atrial ( LA ) connections make achieving electrical isolation ( EI ) challenging . We examined anatomical and technical features associated with resistance to EI during WEPV in a prospect i ve study . METHODS One hundred one consecutive patients with symptomatic AF underwent first-time CA guided by electroanatomic mapping and CT integration ( Cartomerg ) . Following double-transseptal access , WEPV was performed . After completion of PV encirclement , the line was mapped and where no signal could be obtained , CA was performed inside the WE line at the site of earliest PV breakthrough on the circular mapping catheter . Sites of EI were tagged . Anatomic studies of corresponding regions of the venoatrial junction in 24 adult hearts were performed . RESULTS Sites resistant to EI were located at the inferior quadrant ( P < 0.001 ) for the RSPV , superior quadrant ( P < 0.001 ) for the RIPV , and the inferior and anterior quadrants ( P < 0.001 ) for the LSPV . EI was significantly less frequent at the posterior quadrant ( P < 0.001 ) for the LIPV . To achieve EI , CA was necessary inside the WE on the intervenous ridge on the right in 51 % and on the left in 41 % . The LPV/LAA ridge was investigated by anatomic studies that demonstrated considerable variation in the narrowest width ( 3 - 23.7 mm ) and transmural thickness ( 1 - 5 mm ) . CONCLUSION Sites of EI after WEPV have a preferential distribution determined by anatomic features . CA on the intervenous ridge is required in a significant proportion of patients to achieve EI . Atrial folds and ridges increase myocardial thickness creating technical and anatomic challenges for achieving transmural lesions AIMS Pulmonary vein ( PV ) isolation is a curative treatment for patients with atrial fibrillation . The aim of this study was to evaluate prospect ively the effects of adenosine administration on the PV activity and atrio-venous conduction after PV isolation . METHODS AND RESULTS Twenty-nine patients ( 21 m ; age : 55+/-8 years ) were su bmi tted to ostial PV isolation guided by basket catheter recordings . After successful isolation , the effects of a 12 mg intravenous bolus of adenosine were tested in 62 PVs . In 22/62 PVs ( 35 % ) , left atrium (LA)-to-PV conduction was transiently ( 16.6+/-7.1 s , range : 3.8 - 27.9 s ) or permanently ( 3 PVs ) restored in response to adenosine administration . The prevalence of this phenomenon was 39 % in left superior PVs , 43 % in right superior PVs , and 22 % in left inferior PVs ( p=0.365 ) . It occurred more frequently in the presence of dissociated PV activity ( 11/15 PVs , 73 % vs. 11/47 PVs , 23 % ; p=0.002 ) , whereas it was not influenced by the median duration of the radiofrequency current ( RFC ) delivery for each PV [ 19 ( IQR : 12 - 26 ) min vs. 16 ( IQR : 11 - 24 ) min : p=0.636 ] . A lengthening or shortening of the LA-PV conduction time was observed at LA-PV conduction appearance and disappearance in 36 % and 55 % of the cases , respectively . Further RFC applications ( median : 5.5 min , IQR : 4 - 11 min ) at the residual conduction breakthrough(s ) indicated by the basket catheter recordings definitively eliminated adenosine-induced recovery of LA-PV conduction in all cases . Finally , when present , intrinsic PV discharge was invariably depressed by adenosine administration . CONCLUSIONS Adenosine may transiently or permanently re-establish LA-PV conduction after apparently successful PV isolation . This phenomenon is abolished by additional RFC delivery . However , its possible influence on the clinical results of PV ablation must be evaluated by properly design ed , r and omized studies INTRODUCTION Catheter ablation for paroxysmal AF ( PAF ) is limited by an unacceptable recurrence rate , mainly due to pulmonary vein ( PV ) reconnection . Strategies to minimize reconnection include adenosine infusion and also a waiting period of 30 minutes after PV isolation . The aim of the present study was to assess whether these two strategies revealed the same conduction gap . METHODS AND RESULTS In total , 88 consecutive patients ( 54 males , mean age of 60 years ) with drug refractory PAF underwent circumferential PV isolation ( CPVI ) .  After isolation of ipsilateral PVs , with entry and exit block checked using a circular mapping catheter , 20 mg ATP was injected during isoproterenol infusion to reveal dormant conduction gap(s ) . Unless the reconnection revealed by ATP persisted , PVs were further remapped with the circular mapping catheter at 30 minutes postisolation . Totally , PV reconnection was observed in 56 ( 64 % ) patients . 24.3 % veins ( 80/329 ) were found reconnected . Re assessment at 30 minutes postablation was more efficient as compared to ATP induction ( 19.8 % vs 14.6 % for ATP ) . The agreement between these 2 methods is moderate ( kappa value = 0.50 ) . In veins that transiently reconnected after ATP administration and later observed at 30 minutes postablation , 94 % ( 17 of 19 ) of them were found being reconnected with the same gap . CONCLUSION Acute PV reconnection is common , occurring in 64 % of patients , as detected by adenosine infusion and waiting time . Each shows a unique quality as compared to one another . The combined use of these 2 methods may reduce the AF recurrence rate after CPVI BACKGROUND Pulmonary vein ( PV ) isolation ( PVI ) has emerged as an effective therapy for paroxysmal atrial fibrillation ( AF ) . However , AF recurs in up to 50 % of patients , generally because of recovery of PV conduction . Adenosine given during the initial procedure may reveal dormant PV conduction , thereby identifying the need for additional ablation , leading to improved outcomes . The Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination ( ADVICE ) study is a prospect i ve multicentre r and omized trial assessing the impact of adenosine-guided PVI in preventing AF recurrences . METHODS Patients undergoing a first PVI procedure for paroxysmal AF will be recruited . After st and ard PVI is completed , all patients will receive intravenous adenosine in an attempt to unmask dormant conduction . If dormant conduction is elicited , patients will be r and omized to no further ablation ( control group ) or additional adenosine-guided ablation until dormant conduction is abolished . If no dormant conduction is revealed , r and omly selected patients will be followed in a registry . The primary outcome is time to first documented symptomatic AF recurrence . Assuming that dormant conduction is present in 50 % of patients post PVI and symptomatic AF recurs in 45 % of controls , 244 patients with dormant conduction will be required to obtain > 90 % power to detect a difference of 20 % . Thus , a total of 488 patients will be enrolled and followed for 12 months . CONCLUSION The ADVICE trial will assess whether a PVI strategy incorporating elimination of dormant conduction unmasked by intravenous adenosine will decrease the rate of recurrent symptomatic AF compared with st and ard PVI BACKGROUND Although it is well recognized that recovery of pulmonary vein ( PV ) conduction is common among patients who fail atrial fibrillation ( AF ) ablation  , little is known about the precise time course of recurrence . OBJECTIVE To determine the incidence and time course of early recurrence of conduction after PV isolation during AF ablation . METHODS The patient population was composed of 14 consecutive patients ( 9 men [ 64 % ] ; age 56 + /- 7 years ) with AF who underwent radiofrequency catheter ablation via circumferential ablation with PV isolation , determined by a circular mapping catheter .  After successful isolation of the PVs , repeat circular electrode recordings from each PV were obtained at 30 and 60 minutes . RESULTS After complete isolation of all PVs , early PV recurrence was observed in 13 ( 93 % ) patients and 26 veins ( 50 % ) . Seventeen veins ( 33 % ) showed a first recurrence at 30 minutes , while nine veins ( 17 % ) showed a first recurrence at 60 minutes . CONCLUSION The results reveal an extremely high rate of early recurrence of PV conduction following AF ablation . It is particularly notable that about one-fifth of the veins remained isolated at 30 minutes , but subsequently developed recurrence between 30 and 60 minutes . Of the veins that showed early recurrence , one-third developed a first recurrence at 60 minutes . These findings suggest that AF ablation procedures should incorporate a 60-minute waiting period after initial isolation in order to detect early recurrence of conduction 
    Output:
    
Routine adenosine testing is associated with an improvement in freedom from AF post-PVI .
Paradoxically acute adenosine-induced PV reconnection may portend a greater likelihood of AF recurrence despite additional ablation .