J Interv Card Electrophysiol DOI 10.1007/s10840-013-9869-4
The effects of standard electrical PV isolation vs. “pace and ablate” on ATP-provoked PV reconnections Yasuo Okumura & Ichiro Watanabe & Koichi Nagashima & Kazumasa Sonoda & Hiroaki Mano & Naoko Sasaki & Rikitake Kogawa & Keiko Takahashi & Kazuki Iso & Kimie Ohkubo & Toshiko Nakai & Atsushi Hirayama
Received: 25 September 2013 / Accepted: 23 December 2013 # Springer Science+Business Media New York 2014
Abstract Background Catheter ablation procedures for atrial fibrillation (AF) often involve circumferential pulmonary vein isolation (PVI). Lack of reliable identification of conduction gaps along the ablation line necessitates additional ablation within previous lesion sets. We conducted a retrospective comparative study to determine the best PVI strategy for prevention of PV reconnections. Methods and results We compared the outcomes of PVI performed in two groups of patients with AF: those in whom a three-dimensional mapping system and irrigated tip radiofrequency catheter were used to electrically isolate the ipsilateral PVs (31 patients, electrical isolation group) and those in whom “pace and ablate” was performed in the PV antra until pacing at 10 mA and 2 ms no longer captured the atrial myocardium along the ablation line (31 patients, pace and ablate group). A bolus administration of 30 mg of adenosine triphosphate (ATP) revealed dormant PV reconnections more frequently in the electrical isolation group than in the pace and ablate group (28 [90 %] of 31 patients vs. 16 [52 %] of 31 patients, p=0.0005). After re-isolation of the sites of dormant PV conduction, the post-ablation recurrence rates at 1 year were similar (26 vs. 26 %, p=1.000). Conclusion Electrical PVI can usually be achieved without complete circumferential ablation. However, the isolated PVs often show dormant conduction. These findings support the hypothesis that reversible tissue injury contributes to PVI that may be acute but not necessarily durable. Similar outcomes Y. Okumura (*) : I. Watanabe : K. Nagashima : K. Sonoda : H. Mano : N. Sasaki : R. Kogawa : K. Takahashi : K. Iso : K. Ohkubo : T. Nakai : A. Hirayama Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan e-mail: [email protected]
between the two ablation strategies suggest that ATP provocation tests remain necessary to unmask dormant PV conduction. Keywords Pace and ablation . Pulmonary vein isolation . Adenosine triphosphate provocation
1 Introduction Over the past decade, catheter-based pulmonary vein isolation (PVI) has become a widely accepted therapy for patients with symptomatic drug-refractory atrial fibrillation (AF) [1, 2]. However, AF recurrence after catheter ablation occurs in approximately 10–30 % of patients with paroxysmal AF and in even more patients with persistent AF [2]. One contributor to AF recurrence after ablation is PV reconnections, or reconduction [2–4]. PV reconduction has been reported in approximately 80 % of patients who experienced atrial tachyarrhythmias after the initial AF ablation, and the majority of these patients were free of symptoms after re-isolation of the reconnected PVs [3–5]. This raises the question of which ablation strategy is best for achieving a durable, complete PVI. Provocation of dormant PV conduction by adenosine or adenosine triphosphate (ATP) can unmask the latent PV reconnections after ablation and thus has decreased the recurrence of AF [5–7]. By making use of the first 60 min after a successful PVI, potential sites of PV reconnections can be identified, and the AF ablation success rate can be increased [8]. The inability to reliably identify conduction gaps on the ablation line necessitates the placement of additional ablation lines within the previous lesion sets. We conducted a retrospective comparative study to determine the best PVI strategy for prevention of PV reconnections.
J Interv Card Electrophysiol
2 Methods 2.1 Study patients The study group was comprised of 62 consecutive patients with drug-refractory AF (56 men, 6 women; mean age, 56.2± 10.7 years; median duration of AF, 24 [interquartile range 6.8–60] months) who were referred to Nihon University Itabashi Hospital for radiofrequency (RF) catheter ablation between November 2011 and April 2013. In general, between November 2011 and April 2012, we treated patients by extensive ipsilateral encircling PVI (EEPVI). We began treating the patients with the pace and ablate strategy from April 2012 to December 2012. The patients to be included in the study were identified through a review of the hospital records. No patients referred for a repeat ablation were included in the study. Forty of the study patients were treated for paroxysmal AF (spontaneous termination within 7 days), and 22 were treated for nonparoxysmal AF (AF lasting over 7 days). All patients provided written informed consent for the blood sampling, electrophysiologic study, and ablation. Adequate oral anticoagulation was given for at least 1 month before the procedure, and all antiarrhythmic drugs were withdrawn for at least five half-lives prior to the ablation. Upon admission, a physical examination, routine hematology and biochemistry tests, 12-lead electrocardiography (ECG), chest X-ray, and transthoracic and transesophageal echocardiography were performed. Before the ablation, all patients underwent multislice computed tomography with a 320-detector row, dynamic volume scanner (Aquilion ONE; Toshiba Medical Systems, Tokyo, Japan) for a three-dimensional (3D) reconstruction of the left atrium and PVs [9]. The study protocol was approved by the Institutional Review Board of Nihon University Itabashi Hospital. 2.2 Ablation protocol Ablation was performed under sedation achieved with an intravenous infusion of propofol and fentanyl, as previously described [9]. In brief, after vascular access was obtained, a single transseptal puncture was performed and then intravenous heparin was administered to maintain an activated clotting time of around 300 s. After three long sheaths (two SR0 sheaths and one SL1 sheath) were inserted into the LA via a transseptal puncture, two Lasso catheters and a 3.5-mm irrigated tip catheter (ThermoCool, Navistar, Biosense Webster) for ablation were advanced into the LA. The EEPVI was performed guided by double Lasso catheters and a 3D geometric map generated by a NavX (St. Jude Medical, St. Paul, MN) or CARTO (Biosense Webster, Inc., Diamond Bar, CA) mapping system. RF energy was delivered at a maximum power output of 20–30 W, and the upper temperature limit
was set to 41 °C at a saline irrigation rate of 17 mL/min (CoolFlow Pump; Biosense Webster). Each RF energy application was delivered with a point-by-point method in an overlapping manner to achieve an impedance decrease of 5– 10 Ω or a reduction of ≥50 % in the local electrogram amplitude. The patients were assigned to electrical isolation (n=31) or a “pace and ablate” strategy (n=31), according to our standard practice at the time. In the electrical isolation group, electrical isolation was performed by an EEPVI and was confirmed by the presence of entrance and exit block. PV entrance block was defined as the complete absence of PV potentials, and exit block was defined as the absence of left atrial (LA) conduction by pacing (pacing current output— 10 mA amplitude and 2 ms pulse width) from sequential bipolar electrodes of double Lasso catheters positioned at the right or left ipsilateral PVs. In the pace and ablate group, after electrical isolation with the EEPVI was achieved, the complete absence of PV potentials was only confirmed by the double Lasso catheters. Thereafter, unipolar pacing was performed during sinus rhythm just inside the PVs along the ablation line at points approximately 5 mm apart for the confirmation of exit block. Unipolar pacing from the distal electrode of the ablation catheter was performed with a 10-mA amplitude and 2-ms pulse width while consistent catheter tip contact was maintained, as determined by fluoroscopic visualization, surface 3D mapping, and intracardiac electrocardiography. If the left atrium was still excitable by pacing, additional ablation lesions were created until atrial capture was no longer possible at that location. In each group, after the EEPVI was achieved (by electrical isolation alone or by electrical isolation and pace and ablate) and after at least 30 min had elapsed, 30 mg of ATP was injected intravenously to provoke dormant PV conduction [5–7]. If the AF continued even after the EEPVI, an ATPprovoked test was performed after the restoration of sinus rhythm by internal cardioversion. Sites with dormant PV conduction were verified with double Lasso catheters positioned at the right or left PV ostia. The breakthrough sites of dormant PV conduction were categorized according to their PV location, whether they were located at the anterior, posterior, or superior aspect of the right or left superior PVs (RSPVs or LSPVs, respectively), anterior or posterior carina of the PVs, or anterior, posterior, or inferior aspect of the right or left inferior PVs (RIPVs or LIPVs, respectively) (Fig. 1). RF energy was applied to the conduction gaps until disappearance of the ATP-induced dormant PV conduction. In patients in whom AF was inducible and sustained for more than 5 min after the PVI, linear ablation of the LA roof and mitral isthmus and/or a complex fractionated atrial electrogram (CFAE)based ablation in the left atrium was performed. The endpoint of these steps was AF termination during the procedure or LA linear ablation and abolition of all CFAEs in the left atrium if AF was not terminated. A cavo-tricuspid isthmus ablation was
J Interv Card Electrophysiol Fig. 1 Three-dimensional maps of the left atrium show the 16 PV locations segmented for assessing the breakthrough sites of dormant PV conduction. ant anterior, inf inferior, LIPV left inferior pulmonary vein, LL left lateral view, LPV left pulmonary vein, LSPV left superior pulmonary vein, post posterior, RIPV right inferior pulmonary vein, RL right lateral view, RPV right pulmonary vein, RSPV right superior pulmonary vein, sup superior
performed when typical atrial flutter was induced by burst atrial pacing or observed clinically.
2.3 Echocardiographic evaluation Transthoracic echocardiography was performed 1 day before the ablation with an ACUSON Sequoia C256 echocardiography system (Siemens Medical Solutions USA, Inc., Malvern, PA). The LA diameter (LAD) was measured at the end of the T wave, and the left ventricular ejection fraction (LVEF) was assessed by means of M-mode echocardiography (Teichholz’s method). Measurements from three consecutive beats were averaged.
2.5 Comparison between the electrical isolation group and the pace and ablate group Data were compared between the electrical isolation group and the pace and ablate group. The variables included in the comparison were as follows: baseline clinical characteristics, transthoracic echocardiographic variables, the prevalence and distribution of the ATP-provoked PV reconnections, the number of RF applications required for the EEPVI or EEPVI plus pace and ablate or the absence of dormant PV reconnection sites and pacing capture sites along the previous ablation lines, ablation results, and outcomes after ablation.
2.6 Statistical analysis 2.4 Post-ablation follow-up The patients were followed up for at least 6 months after the ablation. For the purpose of the study, we chose a follow-up time of 12 months or as close to 12 months as possible for the data collection. The patients’ antiarrhythmic drugs were resumed after the procedure but then stopped after a 2-month post-ablation blanking period. Other prescribed drugs including antihypertensives and statins were continued during the follow-up period. All patients underwent a routine follow-up examination at our outpatient clinic 2 weeks after the ablation and then 1 month and every 1–3 months thereafter. Twenty-four-hour Holter recordings were scheduled at 3, 6, and 12 months after the ablation. An ECG event recorder was used whenever a patient had any cardiac symptoms. Successful ablation was defined as nonrecurrence of AF lasting more than 30 s on the standard ECG, ECG event monitor, or 24-h Holter recording during the follow-up period after the 2month post-ablation blanking period.
Continuous variables are expressed as the mean ± SD or median values and interquartile ranges. Differences in continuous variables between the electrical isolation group and pace and ablate group were analyzed by an unpaired t test or MannWhitney U test. Differences in categorical variables were analyzed by a chi-square test. A p value of 0.05 was accepted as statistically significant. All statistical analyses were performed with JMP 10 software (SAS Institute, Cary, NC).
3 Results 3.1 Patient characteristics The patient characteristics and transthoracic echocardiographic variables are summarized in Table 1. There was no significant difference in the patients’ clinical characteristics or in the LAD or LVEF between the electrical isolation group and the pace and ablate group.
J Interv Card Electrophysiol Table 1 Clinical characteristics and echocardiographic variables per study group
Age (years) Sex (female) AF duration (months) Body mass index (kg/m2) Nonparoxysmal AF Causal factors Hypertension Diabetes mellitus Heart failure Echocardiographic measures LAD (mm) LVEF (%)
Total (n=62)
Electrical PVI group (n=31)
Pace and ablate group (n=31)
p valuea
56.2±10.7 6 (10) 24 [6.8–60.0] 24.5±3.8 22 (35)
56.5±11.4 5 (16) 24.3 [12.0–60.8] 23.7±3.4 12 (39)
55.9±10.2 1 (3) 24.0 [6.0–48.0] 25.4±4.0 10 (32)
0.8421 0.1953 0.2366 0.0917 0.5953
33 (53) 6 (10) 7 (11)
14 (45) 2 (6) 3 (10)
17 (55) 4 (13) 4 (13)
0.7991 0.6713 1.0000
38.2±5.4 66.8±10.4
37.5±5.1 67.3±8.8
39.2±5.4 66.0±11.3
0.1991 0.6173
The values are the mean ± SD, median [interquartile range], or n (percent) AF atrial fibrillation, LAD left atrial diameter, LVEF left ventricular ejection fraction, PVI pulmonary vein isolation a
Electrical isolation vs. pace and ablate
3.2 Dormant PV conduction provoked by ATP After a successful EEPVI, ATP provoked dormant PV reconnections in a greater percentage of patients in the electrical isolation group than in the pace and ablate group (28 [90 %] of 31 patients vs. 16 [52 %] of 31 patients, p=0.0005). In the electrical isolation group, the number of PV reconnections was 1 PV site in 7 [23 %] patients, 2 PV sites in 16 [52 %], and 3 PV sites in 6 [19 %]. In the pace and ablate group, the number of PV reconnections was 1 PV site in 12 [39 %] patients, 2 PV sites in 2 [6 %], and 3 PV sites in 1 [6 %]; p
The effects of standard electrical PV isolation vs. “pace and ablate” on ATP-provoked PV reconnections Yasuo Okumura & Ichiro Watanabe & Koichi Nagashima & Kazumasa Sonoda & Hiroaki Mano & Naoko Sasaki & Rikitake Kogawa & Keiko Takahashi & Kazuki Iso & Kimie Ohkubo & Toshiko Nakai & Atsushi Hirayama
Received: 25 September 2013 / Accepted: 23 December 2013 # Springer Science+Business Media New York 2014
Abstract Background Catheter ablation procedures for atrial fibrillation (AF) often involve circumferential pulmonary vein isolation (PVI). Lack of reliable identification of conduction gaps along the ablation line necessitates additional ablation within previous lesion sets. We conducted a retrospective comparative study to determine the best PVI strategy for prevention of PV reconnections. Methods and results We compared the outcomes of PVI performed in two groups of patients with AF: those in whom a three-dimensional mapping system and irrigated tip radiofrequency catheter were used to electrically isolate the ipsilateral PVs (31 patients, electrical isolation group) and those in whom “pace and ablate” was performed in the PV antra until pacing at 10 mA and 2 ms no longer captured the atrial myocardium along the ablation line (31 patients, pace and ablate group). A bolus administration of 30 mg of adenosine triphosphate (ATP) revealed dormant PV reconnections more frequently in the electrical isolation group than in the pace and ablate group (28 [90 %] of 31 patients vs. 16 [52 %] of 31 patients, p=0.0005). After re-isolation of the sites of dormant PV conduction, the post-ablation recurrence rates at 1 year were similar (26 vs. 26 %, p=1.000). Conclusion Electrical PVI can usually be achieved without complete circumferential ablation. However, the isolated PVs often show dormant conduction. These findings support the hypothesis that reversible tissue injury contributes to PVI that may be acute but not necessarily durable. Similar outcomes Y. Okumura (*) : I. Watanabe : K. Nagashima : K. Sonoda : H. Mano : N. Sasaki : R. Kogawa : K. Takahashi : K. Iso : K. Ohkubo : T. Nakai : A. Hirayama Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan e-mail: [email protected]
between the two ablation strategies suggest that ATP provocation tests remain necessary to unmask dormant PV conduction. Keywords Pace and ablation . Pulmonary vein isolation . Adenosine triphosphate provocation
1 Introduction Over the past decade, catheter-based pulmonary vein isolation (PVI) has become a widely accepted therapy for patients with symptomatic drug-refractory atrial fibrillation (AF) [1, 2]. However, AF recurrence after catheter ablation occurs in approximately 10–30 % of patients with paroxysmal AF and in even more patients with persistent AF [2]. One contributor to AF recurrence after ablation is PV reconnections, or reconduction [2–4]. PV reconduction has been reported in approximately 80 % of patients who experienced atrial tachyarrhythmias after the initial AF ablation, and the majority of these patients were free of symptoms after re-isolation of the reconnected PVs [3–5]. This raises the question of which ablation strategy is best for achieving a durable, complete PVI. Provocation of dormant PV conduction by adenosine or adenosine triphosphate (ATP) can unmask the latent PV reconnections after ablation and thus has decreased the recurrence of AF [5–7]. By making use of the first 60 min after a successful PVI, potential sites of PV reconnections can be identified, and the AF ablation success rate can be increased [8]. The inability to reliably identify conduction gaps on the ablation line necessitates the placement of additional ablation lines within the previous lesion sets. We conducted a retrospective comparative study to determine the best PVI strategy for prevention of PV reconnections.
J Interv Card Electrophysiol
2 Methods 2.1 Study patients The study group was comprised of 62 consecutive patients with drug-refractory AF (56 men, 6 women; mean age, 56.2± 10.7 years; median duration of AF, 24 [interquartile range 6.8–60] months) who were referred to Nihon University Itabashi Hospital for radiofrequency (RF) catheter ablation between November 2011 and April 2013. In general, between November 2011 and April 2012, we treated patients by extensive ipsilateral encircling PVI (EEPVI). We began treating the patients with the pace and ablate strategy from April 2012 to December 2012. The patients to be included in the study were identified through a review of the hospital records. No patients referred for a repeat ablation were included in the study. Forty of the study patients were treated for paroxysmal AF (spontaneous termination within 7 days), and 22 were treated for nonparoxysmal AF (AF lasting over 7 days). All patients provided written informed consent for the blood sampling, electrophysiologic study, and ablation. Adequate oral anticoagulation was given for at least 1 month before the procedure, and all antiarrhythmic drugs were withdrawn for at least five half-lives prior to the ablation. Upon admission, a physical examination, routine hematology and biochemistry tests, 12-lead electrocardiography (ECG), chest X-ray, and transthoracic and transesophageal echocardiography were performed. Before the ablation, all patients underwent multislice computed tomography with a 320-detector row, dynamic volume scanner (Aquilion ONE; Toshiba Medical Systems, Tokyo, Japan) for a three-dimensional (3D) reconstruction of the left atrium and PVs [9]. The study protocol was approved by the Institutional Review Board of Nihon University Itabashi Hospital. 2.2 Ablation protocol Ablation was performed under sedation achieved with an intravenous infusion of propofol and fentanyl, as previously described [9]. In brief, after vascular access was obtained, a single transseptal puncture was performed and then intravenous heparin was administered to maintain an activated clotting time of around 300 s. After three long sheaths (two SR0 sheaths and one SL1 sheath) were inserted into the LA via a transseptal puncture, two Lasso catheters and a 3.5-mm irrigated tip catheter (ThermoCool, Navistar, Biosense Webster) for ablation were advanced into the LA. The EEPVI was performed guided by double Lasso catheters and a 3D geometric map generated by a NavX (St. Jude Medical, St. Paul, MN) or CARTO (Biosense Webster, Inc., Diamond Bar, CA) mapping system. RF energy was delivered at a maximum power output of 20–30 W, and the upper temperature limit
was set to 41 °C at a saline irrigation rate of 17 mL/min (CoolFlow Pump; Biosense Webster). Each RF energy application was delivered with a point-by-point method in an overlapping manner to achieve an impedance decrease of 5– 10 Ω or a reduction of ≥50 % in the local electrogram amplitude. The patients were assigned to electrical isolation (n=31) or a “pace and ablate” strategy (n=31), according to our standard practice at the time. In the electrical isolation group, electrical isolation was performed by an EEPVI and was confirmed by the presence of entrance and exit block. PV entrance block was defined as the complete absence of PV potentials, and exit block was defined as the absence of left atrial (LA) conduction by pacing (pacing current output— 10 mA amplitude and 2 ms pulse width) from sequential bipolar electrodes of double Lasso catheters positioned at the right or left ipsilateral PVs. In the pace and ablate group, after electrical isolation with the EEPVI was achieved, the complete absence of PV potentials was only confirmed by the double Lasso catheters. Thereafter, unipolar pacing was performed during sinus rhythm just inside the PVs along the ablation line at points approximately 5 mm apart for the confirmation of exit block. Unipolar pacing from the distal electrode of the ablation catheter was performed with a 10-mA amplitude and 2-ms pulse width while consistent catheter tip contact was maintained, as determined by fluoroscopic visualization, surface 3D mapping, and intracardiac electrocardiography. If the left atrium was still excitable by pacing, additional ablation lesions were created until atrial capture was no longer possible at that location. In each group, after the EEPVI was achieved (by electrical isolation alone or by electrical isolation and pace and ablate) and after at least 30 min had elapsed, 30 mg of ATP was injected intravenously to provoke dormant PV conduction [5–7]. If the AF continued even after the EEPVI, an ATPprovoked test was performed after the restoration of sinus rhythm by internal cardioversion. Sites with dormant PV conduction were verified with double Lasso catheters positioned at the right or left PV ostia. The breakthrough sites of dormant PV conduction were categorized according to their PV location, whether they were located at the anterior, posterior, or superior aspect of the right or left superior PVs (RSPVs or LSPVs, respectively), anterior or posterior carina of the PVs, or anterior, posterior, or inferior aspect of the right or left inferior PVs (RIPVs or LIPVs, respectively) (Fig. 1). RF energy was applied to the conduction gaps until disappearance of the ATP-induced dormant PV conduction. In patients in whom AF was inducible and sustained for more than 5 min after the PVI, linear ablation of the LA roof and mitral isthmus and/or a complex fractionated atrial electrogram (CFAE)based ablation in the left atrium was performed. The endpoint of these steps was AF termination during the procedure or LA linear ablation and abolition of all CFAEs in the left atrium if AF was not terminated. A cavo-tricuspid isthmus ablation was
J Interv Card Electrophysiol Fig. 1 Three-dimensional maps of the left atrium show the 16 PV locations segmented for assessing the breakthrough sites of dormant PV conduction. ant anterior, inf inferior, LIPV left inferior pulmonary vein, LL left lateral view, LPV left pulmonary vein, LSPV left superior pulmonary vein, post posterior, RIPV right inferior pulmonary vein, RL right lateral view, RPV right pulmonary vein, RSPV right superior pulmonary vein, sup superior
performed when typical atrial flutter was induced by burst atrial pacing or observed clinically.
2.3 Echocardiographic evaluation Transthoracic echocardiography was performed 1 day before the ablation with an ACUSON Sequoia C256 echocardiography system (Siemens Medical Solutions USA, Inc., Malvern, PA). The LA diameter (LAD) was measured at the end of the T wave, and the left ventricular ejection fraction (LVEF) was assessed by means of M-mode echocardiography (Teichholz’s method). Measurements from three consecutive beats were averaged.
2.5 Comparison between the electrical isolation group and the pace and ablate group Data were compared between the electrical isolation group and the pace and ablate group. The variables included in the comparison were as follows: baseline clinical characteristics, transthoracic echocardiographic variables, the prevalence and distribution of the ATP-provoked PV reconnections, the number of RF applications required for the EEPVI or EEPVI plus pace and ablate or the absence of dormant PV reconnection sites and pacing capture sites along the previous ablation lines, ablation results, and outcomes after ablation.
2.6 Statistical analysis 2.4 Post-ablation follow-up The patients were followed up for at least 6 months after the ablation. For the purpose of the study, we chose a follow-up time of 12 months or as close to 12 months as possible for the data collection. The patients’ antiarrhythmic drugs were resumed after the procedure but then stopped after a 2-month post-ablation blanking period. Other prescribed drugs including antihypertensives and statins were continued during the follow-up period. All patients underwent a routine follow-up examination at our outpatient clinic 2 weeks after the ablation and then 1 month and every 1–3 months thereafter. Twenty-four-hour Holter recordings were scheduled at 3, 6, and 12 months after the ablation. An ECG event recorder was used whenever a patient had any cardiac symptoms. Successful ablation was defined as nonrecurrence of AF lasting more than 30 s on the standard ECG, ECG event monitor, or 24-h Holter recording during the follow-up period after the 2month post-ablation blanking period.
Continuous variables are expressed as the mean ± SD or median values and interquartile ranges. Differences in continuous variables between the electrical isolation group and pace and ablate group were analyzed by an unpaired t test or MannWhitney U test. Differences in categorical variables were analyzed by a chi-square test. A p value of 0.05 was accepted as statistically significant. All statistical analyses were performed with JMP 10 software (SAS Institute, Cary, NC).
3 Results 3.1 Patient characteristics The patient characteristics and transthoracic echocardiographic variables are summarized in Table 1. There was no significant difference in the patients’ clinical characteristics or in the LAD or LVEF between the electrical isolation group and the pace and ablate group.
J Interv Card Electrophysiol Table 1 Clinical characteristics and echocardiographic variables per study group
Age (years) Sex (female) AF duration (months) Body mass index (kg/m2) Nonparoxysmal AF Causal factors Hypertension Diabetes mellitus Heart failure Echocardiographic measures LAD (mm) LVEF (%)
Total (n=62)
Electrical PVI group (n=31)
Pace and ablate group (n=31)
p valuea
56.2±10.7 6 (10) 24 [6.8–60.0] 24.5±3.8 22 (35)
56.5±11.4 5 (16) 24.3 [12.0–60.8] 23.7±3.4 12 (39)
55.9±10.2 1 (3) 24.0 [6.0–48.0] 25.4±4.0 10 (32)
0.8421 0.1953 0.2366 0.0917 0.5953
33 (53) 6 (10) 7 (11)
14 (45) 2 (6) 3 (10)
17 (55) 4 (13) 4 (13)
0.7991 0.6713 1.0000
38.2±5.4 66.8±10.4
37.5±5.1 67.3±8.8
39.2±5.4 66.0±11.3
0.1991 0.6173
The values are the mean ± SD, median [interquartile range], or n (percent) AF atrial fibrillation, LAD left atrial diameter, LVEF left ventricular ejection fraction, PVI pulmonary vein isolation a
Electrical isolation vs. pace and ablate
3.2 Dormant PV conduction provoked by ATP After a successful EEPVI, ATP provoked dormant PV reconnections in a greater percentage of patients in the electrical isolation group than in the pace and ablate group (28 [90 %] of 31 patients vs. 16 [52 %] of 31 patients, p=0.0005). In the electrical isolation group, the number of PV reconnections was 1 PV site in 7 [23 %] patients, 2 PV sites in 16 [52 %], and 3 PV sites in 6 [19 %]. In the pace and ablate group, the number of PV reconnections was 1 PV site in 12 [39 %] patients, 2 PV sites in 2 [6 %], and 3 PV sites in 1 [6 %]; p
