Abstract Background The relationship between atrial electrogram (EGM) characteristics in atrial fibrillation (AF) and those in sinus rhythm (SR) are generally unknown. The activation rate and ...direction may affect EGM characteristics. We examined characteristics of left atrial (LA) EGMs obtained during pacing from different sites. Methods The study included 10 patients undergoing pulmonary vein isolation for AF. Atrial EGMs were recorded from a 64-pole basket catheter placed in the LA, and bipolar EGM amplitudes from the distal electrode pair (1–2) and proximal electrode pair (6–7) from 8 splines were averaged. The high right atrium (HRA), proximal coronary sinus (CSp), and distal coronary sinus (CSd) were paced at 600 ms and 300 ms. Results When the LA voltage at SR was ≥1.5 mV, bipolar voltages of the HRA were greater than those of the CSp, which were greater than those of the CSd, regardless of the pacing cycle length. The shorter pacing cycle length resulted in a reduction of the LA EGM voltage at sites of SR voltage ≥1.5 mV, but no significant difference was seen at sites where the SR EGM amplitude was between >0.5 and <1.5 mV. No significant differences were seen in intra-basket conduction times between pacing cycle lengths of 600 ms and 300 ms at any pacing site. Conclusion The rate and direction-dependent reduction of the amplitude of atrial EGMs may explain, in part, the voltage discordance during SR and AF.
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FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UL, UM, UPCLJ, UPUK, VSZLJ, ZAGLJ, ZRSKP
Background: As we have found a significant correlation between left atrial (LA) voltage during sinus rhythm (SR) and that during atrial fibrillation (AF), we hypothesized that the existence of ...low-voltage zones (LVZs) during AF can be used to identify LVZs during SR. Therefore, we conducted a study to test this hypothesis. Methods: In 8 patients, high-density bipolar voltage mapping (> 300 points) of the left atrium was performed with a 20-pole circular catheter with 4-4-4-mm interelectrode spacing. The left atrium was divided into 7 segments, and the mean LA bipolar voltages recorded over 5 seconds during SR and AF were determined by measurement of the peak-to-peak amplitudes. Results: LVZs identified at each segment were compared between SR and AF. LA bipolar voltages obtained during SR and AF correlated positively (r = 0.74, p < 0.0001). With the low voltage during SR defined as < 0.5 mV, the low voltage of < 0.2 mV during AF approximately matched the low LVZs mapped during SR. Conclusions: These findings indicate that LVZs of < 0.5 mV during SR could be predicted from LVZs identified during AF by designating a threshold AF voltage of 0.2 mV.
Purpose
We sought to better understand the association between and clinical implications of ganglionated plexi (GPs), epicardial adipose tissue (EAT) in the left atrium (LA), and the initiation and ...maintenance of atrial fibrillation (AF).
Methods
Three-dimensional (3D) computed tomography (CT) reconstruction images of the LA, PVs, and LA-EAT were merged with the LA geometry for 25 with paroxysmal AF (PAF) and 15 with persistent AF (PerAF) scheduled for ablation. High-frequency stimulation (20 Hz, 25 mA, 10 ms) was performed at three sites within each of the five major anatomical LA GPs (superior left, inferior left, anterior right, inferior right, and Marshall tract GPs) to elicit vagal responses. Correspondence between the five GP areas and vagal response sites, LA-EAT, and complex fractionated atrial electrograms (CFAEs) was examined. The long-term outcomes of adjuvant LA-EAT-based ablation were assessed in 31 patients with PAF and 102 with PerAF.
Results
LA-EAT overlapped 93 ± 14 % of five major anatomical GP areas, and the vagal response sites and CFAE sites corresponded to 77 ± 23 and 76 ± 25 %, respectively (
p <
0.05 for both vs. LA-EAT locations). The EAT-based ablation eliminated 97.6 % of the vagal response sites and lengthened the AF cycle from 160 ± 26 to 193 ± 27 ms (
p <
0.001). The 2-year arrhythmia-free rate after EAT-based ablation was 72 % in the PAF group and 73 % in the PerAF group (
p =
0.614).
Conclusions
LA-EAT tends to overlie the major anatomical GP areas including most of the active GP response sites and CFAEs associated with AF. Ablation of GPs and CFAEs may explain the long-term efficacy of EAT-based ablation following extensive encircling pulmonary vein isolation (EEPVI) for AF.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Purpose
The usefulness of electrogram (EGM)-based information has been reported for assessing lesion transmurality during atrial fibrillation (AF) ablation, but the wall thickness of the pulmonary ...vein-left atrial (PV-LA) junction has not been considered. We conducted a study to evaluate the relation between PV-LA junction wall thickness and the presence of adenosine triphosphate (ATP)-provoked dormant PV conduction.
Methods
Eighteen AF patients underwent extensive encircling pulmonary vein isolation (EEPVI) with a target CF of >10 g. RF energy was delivered point-by-point at a power setting of 25–30 W for 30 s, and EGM-based information (change in filtered unipolar EGM morphology and bipolar EGM amplitude), decrease in impedance, CF, and CT-based measurement of the PV-LA junction wall thickness were characterized at sites of ATP-provoked dormant conduction.
Results
After EEPVI, ATP-induced dormant conduction was observed at 12 of the 288 PV sites (8 segments per ipsilateral PVs × 2 × 18 patients). Of the 974 ablation points, 72 were located at dormant conduction sites and were strongly associated with thickened PV-LA junction walls (1.02± 0.23 vs. 0.86 ± 0.26 mm,
p
< 0.0001) and decreased impedance (13.3 ± 6.4 vs. 14.9 ± 7.1 Ω,
p
= 0.0498) but not with EGM-based information or CF. Multivariate analysis identified the thickened PV-LA junction wall as the strongest predictor of dormant conduction.
Conclusions
A thickened PV-LA junction wall is a robust predictor of ATP-provoked dormant conduction; EGM-based information appears to be insufficient for ensuring adequate lesions during CF-guided EEPVI.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cryoballoon catheter ablation was developed to simplify ablation for atrial fibrillation (AF). Initial enthusiasm for its widespread use has been dampened by phrenic nerve (PN) injury (PNI).
The ...purpose of this study was to assess the effect of cryoballoon inflation at the right superior pulmonary vein (RSPV) orifice on PN location and to elucidate the potential mechanism of PNI.
Twenty patients with paroxysmal atrial fibrillation underwent ablation performed with a second-generation 28-mm cryoballoon catheter. Before ablation, the pacing-determined PN course was delineated along the right atrium. PN location and its relation to the RSPV as well as RSPV surface distortions after balloon inflation were established with a NavX mapping system.
During RSPV ablation, the inflated balloon surface extended anteriorly 6.3 ± 1.8 mm outside the RSPV. This narrowed the distance between the PN capture points in the RSPV vs PN location from 11.4 ± 5.0 mm to 7.5 ± 5.0 mm (P = .0002) and increased the PN capture area from 1.9 ± 1.3 cm(2) to 3.2 ± 1.8 cm(2) (P = .0004). Furthermore, the PN capture points shifted toward the orifice within the RSPV and after balloon inflation were located significantly closer to the orifice in the 3 patients with transient PNI than in those without PNI.
Cryoballoon inflation at the RSPV orifice alters PV/left atrial surface geometry, reducing the distance between the energy delivery source and the PN and increasing PN area, possibly explaining the mechanism of PNI. PN pacing within the RSPV after balloon inflation may be useful for preventing PNI.
Purpose
Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is mainly due to PV reconnections. Patient-specific tissue characteristics that may contribute remain unidentified. ...This study aimed to assess the relationship between the bipolar electrogram voltage amplitudes recorded from the PV-left atrial (LA) junction and acute PV reconnection sites.
Methods
Three-dimensional LA voltage maps created before an extensive encircling PVI in 47 AF patients (31 men; mean age 62 ± 11 years) were examined for an association between the EGM voltage amplitude recorded from the PV-LA junction and acute post-PVI PV reconnections (spontaneous PV reconnections and/or ATP-provoked dormant PV conduction).
Results
Acute PV reconnections were observed in 17 patients (36%) and in 24 (3%) of the 748 PV segments (16 segments per patient) and were associated with relatively high bipolar voltage amplitudes (3.26 ± 0.85 vs. 1.79 ± 1.15 mV,
p
< 0.0001) and a relatively low mean force-time integral (FTI) (428 ± 56 vs. 473 ± 76 gs,
p
= 0.0039) as well as FTI/PV-LA bipolar voltage (137 106, 166 vs. 295 193, 498 gs/mV,
p
< 0.0001). An analysis of the receiver operating characteristic curves revealed a high prognostic performance of the LA bipolar voltage and FTI/PV-LA bipolar voltage for acute PV reconnections (areas under the curve: 0.86 and 0.89, respectively); the best cutoff values were >2.12 mV and ≤183 gs/mV, respectively.
Conclusions
The PV-LA voltage on the PV-encircling ablation line and FTI/PV-LA voltage were related to the acute post-PVI PV reconnections. A more durable ablation strategy is warranted for high-voltage zones.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Introduction High dominant frequency (DF) sites during atrial fibrillation (AF) play an important role in the perpetuation of AF. We investigated the relationship between the DFs from ...intracardiac electrograms (iEGM) and the surface electrocardiogram (ECG) during AF, and the relationship between the surface ECG DF and atrial remodeling. Methods In 48 patients (57 ± 11 years, 47 males, 20 paroxysmal), the V1–6 precordial leads and specific V7–9 ECG leads were recorded for 8 s for an off-line analysis before AF ablation. The QRS-T complex was canceled by a template subtraction algorithm using the CEPAS™ system (Cuoretech Pty Ltd, Sydney, Australia). The iEGM DF maps, reconstructed using the Ensite NavX (St. Jude Medical, Inc., St. Paul, MN, USA) system, were simultaneously created for the right atrium and left atrium (LA) during AF. Results The DF in leads V8 and V9 correlated well with the DF in the LA floor ( R = 0.55, p < 0.01; R = 0.68, p < 0.01, respectively), and that in V1 with the right inferior pulmonary vein ( R = 0.45, p = 0.01). Persistent AF patients had a significantly lower DF in lead V9 (5.7 ± 1.0 Hz vs. 6.7 ± 1.5 Hz, p = 0.02) than paroxysmal AF patients. Conclusions A frequency analysis from lead V9 reflects the LA electrical activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Dormant pulmonary vein (PV) conduction revealed by adenosine/adenosine triphosphate (ATP) provocation test and exit block to the left atrium by pacing from the PV side of the ablation line (“pace and ...ablate” method) are used to ensure durable pulmonary vein isolation (PVI). However, the mechanistic relation between ATP-provoked PV reconnection and the unexcitable gap along the ablation line is unclear. Forty-five patients with atrial fibrillation (AF) (paroxysmal: 31 patients, persistent: 14 patients; age: 61.1 ± 9.7 years) underwent extensive encircling PVI (EEPVI, 179 PVs). After completion of EEPVI, an ATP provocation test (30 mg, bolus injection) and unipolar pacing (output, 10 mA; pulse width, 2 ms) were performed along the previous EEPVI ablation line to identify excitable gaps. Dormant conduction was revealed in 29 (34 sites) of 179 PVs (16.2%) after EEP-VI (22/45 patients). Pace capture was revealed in 59 (89 sites) of 179 PVs (33.0%) after EEPVI (39/45 patients), and overlapping sites, ie, sites showing both dormant conduction and pace capture, were observed in 22 of 179 (12.3%) PVs (17/45 patients). Some of the ATP-provoked dormant PV reconnection sites were identical to the sites with excitable gaps revealed by pace capture, but most of the PV sites were differently distributed, suggesting that the main underling mechanism differs between these two forms of reconnection. These findings also suggest that performance of the ATP provocation test followed by the “pace and ablate” method can reduce the occurrence of chronic PV reconnections.
Background
The association between circulating adiponectin levels and atrial fibrillation (AF) is uncertain. We, therefore, investigated whether an increased serum adiponectin level is implicated in ...the long‐term recurrence of AF after ablation therapy.
Methods
Our study included 100 consecutive patients (88 men; median age, 57.9±10.9 years) who underwent catheter ablation for AF at our hospital between 2011 and 2013. The adiponectin and N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) levels were measured before ablation and compared between those in whom AF recurred and those in whom AF did not recur.
Results
Elevation in adiponectin levels was significantly associated with female sex, non‐paroxysmal AF, heart failure, higher NT‐proBNP and matrix metallo‐proteinase‐2 levels, and lower body mass index. After a stepwise adjustment for any potential confounding variables, the adiponectin levels remained significantly associated with female sex (beta=0.2601, P=0.0041), non‐paroxysmal AF (beta=0.2708, P=0.0080), and higher NT‐proBNP levels (beta=0.2536, P= 0.0138). During the median follow‐up period of 26.2 months, AF recurred in 48 of the 100 patients. Stepwise multivariate adjustment showed that an increased log‐transformed NT‐proBNP (Hazard ratio HR, 2.18; 95% confidence interval CI 1.25–4.00; P=0.0055), longer duration of AF (HR, 1.87; 95%CI 1.01–3.76; P=0.0465), and decreased left ventricular ejection fraction (HR, 0.96; 95%CI 0.93–0.99; P=0.0391) were independent predictors of recurrent AF after catheter ablation, but adiponectin was not.
Conclusions
Our data indicated that adiponectin was partially responsible for progression of AF, but the correlation between adiponectin levels and AF recurrence was not significant.
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FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UL, UM, UPCLJ, UPUK, VSZLJ, ZAGLJ, ZRSKP
Catheter tip-derived contact force (CF) and 3-dimensional (3D) maps are key to mapping and ablation of atrial fibrillation.
This study sought to determine the relation between CF and 3D map surfaces.
...We conducted a validation study of Carto-based 3D ultrasound (3D-US) and 3D-US merged with computed tomography (3D-Merge-CT) left atrium/pulmonary vein images. Under fluoroscopic guidance, 1361 mapping points (20 patients) with CFs and electrogram information were randomly acquired around the PVs.
CF correlated weakly with the distance of mapping points from the 3D-Merge-CT (r = 0.27; P < .001) and 3D-US (r = 0.22; P < .001) surfaces but not with bipolar voltage (r = -0.01; P = .2400). Low CF (0-4 g) yielded points close to the 3D-US surface; moderate (5-9 g) and high CFs (10-20 g) generated points beyond the surface (0.1 ± 3.9, 1.4 ± 3.4, and 2.3 ± 3.4 mm; P < .05 for each). Low, moderate, and high CFs yielded points below, close to, and beyond the 3D-Merge-CT surface (-1.2 ± 3.7, 0.4 ± 3.0, and 1.0 ± 2.9 mm; P < .05 for each).
Poor correlation between CF and the distance of mapping points from the 3D map surfaces and electrogram information shows the limitation of 3D mapping and electrogram information for predicting good contact. In addition, mapping seems to require far less CF than ablation requires.
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