Symptomatic periesophageal vagal nerve injury by different energy sources during atrial fibrillation ablation.

Background: Symptomatic gastric hypomotility (SGH) is a rare but major complication of atrial fibrillation (AF) ablation, but data on this are scarce. Objective: We compared the clinical course of SGH occurring with different energy sources. Methods: This multicenter study retrospectively collected the characteristics and clinical outcomes of patients with SGH after AF ablation. Results: The data of 93 patients (67.0 ± 11.2 years, 68 men, 52 paroxysmal AF) with SGH after AF ablation were collected from 23 cardiovascular centers. Left atrial (LA) ablation sets included pulmonary vein isolation (PVI) alone, a PVI plus a roof-line, and an LA posterior wall isolation in 42 (45.2%), 11 (11.8%), and 40 (43.0%) patients, respectively. LA ablation was performed by radiofrequency ablation, cryoballoon ablation, or both in 38 (40.8%), 38 (40.8%), and 17 (18.3%) patients, respectively. SGH diagnoses were confirmed at 2 (1-4) days post-procedure, and 28 (30.1%) patients required re-hospitalizations. Fasting was required in 81 (92.0%) patients for 4 (2.5-5) days; the total hospitalization duration was 11 [7-19.8] days. After conservative treatment, symptoms disappeared in 22.3% of patients at 1 month, 48.9% at 2 months, 57.6% at 3 months, 84.6% at 6 months, and 89.7% at 12 months, however, one patient required surgery after radiofrequency ablation. Symptoms persisted for >1-year post-procedure in 7 patients. The outcomes were similar regardless of the energy source and LA lesion set. Conclusions: The clinical course of SGH was similar regardless of the energy source. The diagnosis was often delayed, and most recovered within 6 months, yet could persist for over 1 year in 10%.

Treatment of atrial tachycardia arising after superior transseptal approach mitral valve surgery: Insights from ultra-high-density mapping to prevent atrioventricular block.

INTRODUCTION: Mitral valve surgery employing a superior transseptal approach (STA) is associated with arrhythmogenicity and intra-atrial conduction delay, despite being optimal for visualization of the surgical field. It is sometimes difficult to treat atrial tachycardias (AT) that arise after STA. To investigate AT circuits that arise after STA in detail in order to identify the optimal ablation line, using ultra-high-resolution mapping (UHRM). METHODS: We retrospectively analyzed 12 AT from 10 patients (median age 70 years, nine males) who had undergone STA surgery. The tachycardias were mapped using the Rhythmia mapping system (Boston Scientific, Natick, Massachusetts). RESULTS: The 12 STA-related AT (STA-AT) circuits were classifiable as follows according to location of the optimal ablation line: (1) peri-septal incision STA-AT (n = 3), (2) cavotricuspid isthmus (CTI) dependent STA-AT (n = 7), and (3) biatrial tachycardia (n = 2). Radiofrequency (RF) application terminated 11 of the 12 STA-AT. We found that difference in STA-AT circuit type was due to characteristics of the septal incision line made for STA. UHRM was important in identifying optimal ablation sites that did not create additional conduction disturbances in the right atrium (RA). CONCLUSIONS: ATs after STA involve complex arrhythmia circuits due to multiple and long incision lines in the RA. Accurate understanding of the arrhythmia circuit and sinus conduction in the RA after STA is recommended for treating post-surgical tachycardia in a minimally invasive manner.

Mapping and ablation of left atrial roof-dependent tachycardias using an ultra-high resolution mapping system.

BACKGROUND: Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high resolution mapping system. METHODS: This study included 22 consecutive LARTs in 21 patients who underwent AT mapping/ablation using Rhythmia systems. RESULTS: Three, 13, 4, and 2 LART patients were cardiac intervention naïve (Group-A), post-roof line ablation (Group-B), post-atrial fibrillation ablation without linear ablation (Group-C), and post-cardiac surgery (Group-D), respectively. The mean AT cycle length was 244 ± 43 ms. Coronary sinus activation was proximal-to-distal or distal-to-proximal in 16 (72.7%) ATs. The activation map revealed 13 (59.1%) clockwise and 9 (40.9%) counter-clockwise LARTs. A 12-lead synchronous isoelectric interval was observed in 10/19 (52.6%) LARTs. The slow conduction area was identified on the LA roof, anterior/septal wall, and posterior wall in 18, 6, and 2 ATs, respectively. Twenty concomitant ATs among 13 procedures were also eliminated, and peri-mitral AT coexisted in 7 of 9 non-group-B patients. In group-B, the conduction gap was predominantly located on the mid-roof. Sustained LARTs were terminated by a single application and linear ablation in 6 (27.3%) and 9 (40.9%), while converting to other ATs in 7 (31.8%) LARTs. Complete linear block was created without any complications in all, however, ablation at the mid-posterior wall was required to achieve block in 4 (18.2%) procedures. During 14.0 (6.5-28.5) months of follow-up, 17 (81.0%) and 19 (90.5%) patients were free from any atrial tachyarrhythmias after single and last procedures. CONCLUSIONS: The LART mechanisms were distinct in individual patients, and elimination of all concomitant ATs was required for the management.

Association between pericoronary adipose tissue attenuation and outcome after second-generation cryoballoon ablation for atrial fibrillation.

OBJECTIVES: Previous studies reported the association between inflammation and atrial fibrillation (AF). Pericoronary adipose tissue (PCAT) attenuation, PCATA, on cardiac CT angiography (CTA) reflects pericoronary inflammation. We hypothesized that the PCATA predicts AF recurrence after cryoballoon ablation (CBA) for paroxysmal and persistent AF. METHODS: We studied 364 patients (median age, 65 years) with persistent (n = 41) and paroxysmal (n = 323) AF undergoing successful first-session second-generation CBA with pre-ablation cardiac CTA. Three-vessel (3V)-PCATA was defined as the mean CT attenuation value of PCAT of all three major coronary arteries. Predictors of AF recurrence during follow-up were evaluated. RESULTS: AF recurrence after the 3-month blanking period was detected in 90 patients (24.7%) during the median follow-up of 26 (interquartile range, 19-42) months. AF recurrence was associated with prior stroke and statin use, NT-proBNP and high-sensitivity cardiac troponin-I levels, left ventricular dimension, left atrial volume index (LAVI), 3V-PCATA, and early AF recurrence during the blanking period. On multivariable Cox proportional hazard analysis, prior stroke (hazard ratio [HR], 2.208, 95% confidence interval [CI], 1.166-4.180, p = 0.015), LAVI (HR, 1.030, 95% CI, 1.010-1.051, p = 0.003), 3V-PCATA (HR, 1.034, 95% CI, 1.001-1.069, p = 0.046), and early AF recurrence (HR, 2.858, 95% CI, 1.855-4.405, p < 0.001) remained statistically significant. CONCLUSION: Pre-ablation CTA-derived 3V-PCATA, representing pericoronary inflammation, was an independent predictor of recurrence after first-session AF ablation using a second-generation cryoballoon. ADVANCES IN KNOWLEDGE: Assessment of 3V-PCATA may identify patients at high risk of AF recurrence after CBA for AF.

Real-World Safety Profile of Atrial Fibrillation Ablation Using a Second-Generation Cryoballoon in Japan: Insight From a Large Multicenter Observational Study.

OBJECTIVES: This study sought to investigate the incidence and characteristics of the real-world safety profile of second-generation cryoballoon ablation (2nd-CBA) in Japan. BACKGROUND: Pulmonary vein isolation using second-generation cryoballoons is an accepted atrial fibrillation ablation strategy. METHODS: This multicenter observational study included 4,173 patients with atrial fibrillation (3,807 paroxysmal) who underwent a 2nd-CBA in 18 participating centers. The baseline data and details of all procedure-related complications within 3 months post-procedure in consecutive patients from the first case at each center were retrospectively collected. RESULTS: Adjunctive ablation after the pulmonary vein isolation was performed in 2,745 (65.8%) patients. Complications associated with the entire procedure were observed in 206 (4.9%) total patients, and in the multivariate analysis, the age (odds ratio: 1.015; 95% confidence interval: 1.001 to 1.030; p = 0.035) and study period were predictors. Air embolisms manifesting as ST-segment elevation and cardiac tamponade requiring drainage occurred in 63 (1.5%) and 15 (0.36%) patients, respectively. Six (0.14%) patients had strokes/transient ischemic attacks, among whom 5 underwent ablation under an interrupted anticoagulation regimen. No atrioesophageal fistulae occurred; however, 10 (0.24%) patients had symptomatic gastric hypomotility. Esophageal temperature monitoring did not reduce the incidence, and the incidence was significantly higher in patients with adjunctive posterior wall isolations or mitral isthmus ablation than those without (p = 0.004). Phrenic nerve injury occurred during the 2nd-CBA in 58 (1.4%) patients; however, all were asymptomatic and recovered within 13 months. One patient died of aspiration pneumonia. CONCLUSIONS: This study had a high safety profile of 2nd-CBA despite including the early experience and high rate of adjunctive ablation. Care should be taken for air embolisms during 2nd-CBA.

Mapping and ablation of clinical spontaneous perimitral atrial tachycardias using an ultra-high-resolution mapping system.

BACKGROUND: Perimitral atrial tachycardias (PMATs) are common atrial tachycardias (ATs), yet their mechanisms vary. OBJECTIVE: The purpose of this study was to characterize clinical spontaneous PMATs using an ultra-high-resolution (UHR) mapping system. METHODS: The study included 32 consecutive PMATs in 31 patients who had undergone AT mapping/ablation using a UHR mapping system. RESULTS: Six, 10, 11, and 5 PMATs occurred in cardiac intervention-naïve (group A), post-lateral/posterior mitral isthmus linear ablation (group B), post-atrial fibrillation ablation without mitral isthmus linear ablation (group C), and post-cardiac surgery (group D) patients, respectively. Group A patients tended to be older, more likely were female, and had sinus node or atrioventricular conduction disturbances more frequently. A 12-lead synchronous isoelectric interval was observed in 15 PMATs (46.9%). Coronary sinus activation was proximal to distal or distal to proximal except in 3 PMATs with straight patterns due to epicardial gaps. Left atrial anterior/septal wall (LAASW) low-voltage areas were smallest in group B. Slow conduction areas (SCAs) were identified in 26 PMATs (81.2%) and were located on the LAASW in all group A and group D patients. Conduction velocity in the SCAs was slowest in group B. In group B, all PMATs were terminated by single applications, and the gaps were located epicardially in 5 of 10 (50%). Anterior (n = 23) or lateral/posterior (n = 9) mitral isthmus linear block was successfully created without any complications in all. Twenty-five concomitant ATs among 18 patients (58.1%) also were eliminated. During a median of 20.0 (11.0-40.0) months of follow-up, 28 patients (90.3%) were free from any atrial tachyarrhythmias. CONCLUSION: An UHR mapping-guided approach with identification of the individual tachycardia mechanism should be the preferred strategy given the distinct and complex arrhythmia mechanisms.

Circulatory dynamics changes are an additional predictor of successful pulmonary vein isolation during cryoballoon ablation.

The association between circulatory dynamics changes during cryoballoon applications and a successful pulmonary vein isolation (PVI) is unknown. Seventy atrial fibrillation patients who underwent PVI with 28-mm second-generation cryoballoons and single 3-min freezes were included. Intra-procedural parameters including circulatory dynamics changes during cryoapplications, were compared between 113 successful applications (30 left superior PVs[LSPVs], 30 left inferior PVs[LIPVs], 25 right superior PVs[RSPVs], and 28 right inferior PVs[RIPVs]) and 47 failed applications (10 LSPVs, 9 LIPVs, 8 RSPVs, and 20 RIPVs). In all individual PVs, lower nadir balloon temperatures (MinTemps) and longer thawing times (ThawTimes) significantly predicted a successful PVI. In addition, greater systolic blood pressure drops following releasing the PV occlusion (SBP-drops) significantly predicted a successful right PV PVI, and longer elapse times during SBP-drops significantly predicted a successful RIPV PVI. Composite parameters incorporating MinTemps and ThawTimes, SBP-drops, and ThawTimes showed the highest area under the curve to predict a successful left PV (0.876 for LSPVs, 0.851 for LIPVs) and right PV (0.927 for RSPVs, 0.980 for RIPVs) PVI, respectively. If the ThawTime (≥ 30 s) and SBP-drop (≤ - 21 mmHg) cutoff values were achieved for the RIPVs, the positive predictive value was 100%. In contrast, if both criteria were not achieved for the RIPVs, the negative predictive value was 100%. In the second-generation cryoballoon PVI, the MinTemp and ThawTime were significantly associated with acute success for all four PVs. In addition, SBP-drops further improved the accuracy of predicting a successful right PV PVI, especially of the RIPV.

Utility of low-dose adenosine triphosphate sensitivity in slow-fast atrioventricular nodal reentrant tachycardia.

PURPOSE: Low-dose adenosine triphosphate (LD-ATP) is useful for diagnosing ATP-sensitive atrial tachycardia. However, the clinical implications of the sensitivity of LD-ATP in atrioventricular nodal reentrant tachycardia (AVNRT) still remain unknown. This study aimed to evaluate the mechanism of LD-ATP sensitivity in slow-fast AVNRT. METHODS: We estimated the sensitivity of LD-ATP in slow-fast AVNRT by a 2-4-mg ATP intravenous injection during the tachycardia. We evaluated the atrial-His (A-H) interval, tachycardia termination mode, prevalence of a lower common pathway (LCP), and successful ablation site in slow-fast AVNRT with LD-ATP sensitivity. LCPs were defined as His-atrial interval differences of at least 5 ms between that during ventricular pacing at the tachycardia cycle length and that during the tachycardia. RESULTS: Twenty-eight patients (mean age = 58 ± 11 years old, 18 females) with slow-fast AVNRT, who underwent catheter ablation of the antegrade slow pathway, were enrolled. Seventeen of 28 (61%) patients had LD-ATP sensitivity defined as termination of the tachycardia and/or a prolongation of the A-H interval of over 30 ms after an LD-ATP injection. The patients with LD-ATP sensitivity had a significantly higher prevalence of an LCP than those without (15/17 vs0/11, P < 0.0001). The successful ablation site in the LD-ATP sensitive group was significantly closer to the His bundle area than that in the LD-ATP nonsensitive group (13.3 ± 3.8 vs 20.5 ± 5.4 mm; distance to His bundle area in the left anterior oblique fluoroscopic view, P < 0.0001). CONCLUSIONS: LD-ATP sensitivity in slow-fast AVNRT may suggest the existence of an LCP. The successful ablation site in patients with LD-ATP sensitivity could be closer to the His bundle region.

Silent cerebral events/lesions after second-generation cryoballoon ablation: How can we reduce the risk of silent strokes?

BACKGROUND: Atrial fibrillation (AF) ablation is associated with a substantial risk of silent cerebral events/lesions (SCEs/SCLs) detected on magnetic resonance imaging (MRI). OBJECTIVE: The purpose of this study was to investigate the factors associated with the incidence of SCEs/SCLs during second-generation cryoballoon ablation. METHODS: Two hundred fifty-six AF patients underwent brain MRI 1 day after pulmonary vein (PV) isolation using second-generation cryoballoons with a single 28-mm balloon and short freeze strategy. RESULTS: Overall, 991 of 1016 PVs (97.5%) were successfully isolated by 4.9 ± 1.3 cryoballoon applications per patient, and 25 PVs required touch-up radiofrequency ablation. The total procedure time was 72.7 ± 26.1 minutes. SCEs and SCLs were detected in 68 (26.5%) and 27 (10.5%) patients, respectively. None of the patients reported any neurologic symptoms. Reinsertion of once withdrawn cryoballoons and subsequent applications significantly increased the incidence of SCEs (odds ratio [OR] 2.057; 95% confidential interval [CI] 1.051-4.028; P = .035), and additional left atrial mapping with a multielectrode catheter significantly increased the incidence of SCLs (OR 3.317; 95% CI 1.365-8.056; P = .008). Transient coronary air embolisms were significantly associated with the incidence of SCLs (OR 3.447; 95% CI 1.015-11.702; P = 0.047). On the contrary, an uninterrupted anticoagulation regimen, use of radiofrequency deliveries for transseptal access, cryoballoon air removal with extracorporeal balloon inflations, strength of the MRI magnet, internal electrical cardioversion, and touch-up ablation were not associated with the incidence of SCEs/SCLs. CONCLUSION: A significant number of SCE/SCL occurrences was observed after second-generation cryoballoon ablation procedures. These results suggest that air embolisms are the main mechanism of SCEs/SCLs, and the injected air volume might determine the lesion type.

Atrioventricular conduction disturbance during pulmonary vein isolation using the second-generation cryoballoon - Vagal impact of cryoballoon ablation.

BACKGROUND: Vagal reactions of the sinus node during pulmonary vein isolation (PVI) have been reported, however, data on intra-procedural atrioventricular conduction disturbances have been sparse. The present study aimed to investigate the clinical characteristics of atrioventricular conduction block (AVB) during PVI using second-generation cryoballoons. METHODS: A total of 2252 PVs among 568 consecutive atrial fibrillation patients undergoing PVI with 28-mm cryoballoons were analyzed. In 44 patients, left superior PVs (LSPVs) were initially targeted (initial-LSPV-group). In the remaining 524 patients, LSPVs were targeted following right superior PVs (RSPVs) (initial-RSPV-group). RESULTS: Marked sinus arrests/bradycardia occurred in 14 patients only in the initial-LSPV-group, and the incidence was significantly higher in the initial-LSPV than initial-RSPV-group (14/44 vs. 0/524, p < 0.001). Intra-procedural AVB with 3.6 [1.9-8.2] second maximal RR intervals appeared in 12 patients during freezing (n = 1) or after balloon deflation following freezing (n = 11). The targeted PVs were the LSPV, left common PV, right inferior PV, and RSPV in 8, 1, 2, and 1 patients, respectively. The incidence was similar between the initial-LSPV and initial-RSPV-groups (1/44 vs. 11/524, p = 0.938). Four patients exhibited complete AVB with more than a 6 s maximal RR interval. Three patients experienced AVB during atrial fibrillation. AVB was observed a median of 23.0 [15.0-70.0] seconds after balloon deflation and 76.0 [60.0-125.0] seconds after freezing termination. AVB persisted for 56.0 [36.0-110.0] seconds, and all recovered spontaneously with or without requiring back-up pacing. CONCLUSIONS: A marked transient AV conduction disturbance could occur after balloon deflation, especially during LSPV ablation, regardless of the order of targeted PVs.

Characteristics of Phrenic Nerve Injury During Pulmonary Vein Isolation Using a 28-mm Second-Generation Cryoballoon and Short Freeze Strategy.

BACKGROUND: The reported incidence of phrenic nerve injury (PNI) varies owing to different definitions, balloon generations, balloon size, freezing regimen, and protective maneuvers. We evaluated the incidence, predictors, and outcome of PNI during cryoballoon pulmonary vein isolation in a large population. METHODS AND RESULTS: Five hundred fifty atrial fibrillation patients underwent pulmonary vein isolation using one 28-mm second-generation cryoballoon and single 3-minute freeze strategy under diaphragmatic compound motor action potential (CMAP) monitoring. A total of 34 (6.2%) patients experienced PNI during the right superior and inferior pulmonary vein ablation in 30 and 4 patients, respectively. Applications were interrupted using double-stop techniques after 136 [104-158] second applications, and a pulmonary vein isolation was already achieved in all but one case. The baseline CMAP amplitude and timing of deflation (CMAPdef) were 0.75±0.30 and 0.17±0.17 mV, respectively. Persistent atrial fibrillation, larger right superior pulmonary vein ostia, and deeper balloon positions were associated with higher incidences of PNI. The CMAPdef predicted a PNI recovery delay, and the best cutoff value for predicting PNI recovery by the next day was 0.20 mV (sensitivity 57.1%, specificity 100%). Among 6 patients undergoing second procedures 8.5 (6.7-15.0) months later, the right superior pulmonary vein was durable in 3 with >120 second applications. Despite active balloon deflation, no significant pulmonary vein stenosis was observed in 15 right superior pulmonary veins evaluated 6 (5-9) months later. No patients had symptoms, and the PNI recovered 1 day and 1 month postprocedure in 21 and 4 patients, respectively. CONCLUSIONS: PNI resulting from cryoballoon ablation was reversible. The double-stop technique is safe, and immediate active deflation following a CMAP decrease appears to be essential for faster PNI recovery.

Circulatory Dynamics During Pulmonary Vein Isolation Using the Second-Generation Cryoballoon.

BACKGROUND: Circulatory dynamics change during pulmonary vein (PV) isolation using cryoballoons. This study sought to investigate the circulatory dynamics during cryoballoon-based PV isolation procedures and the contributing factors. METHODS AND RESULTS: This study retrospectively included 35 atrial fibrillation patients who underwent PV isolation with 28-mm second-generation cryoballoons and single 3-minute freeze techniques. Blood pressures were continuously monitored via arterial lines. The left ventricular function was evaluated with intracardiac echocardiography throughout the procedure in 5 additional patients. Overall, 126 cryoapplications without interrupting freezing were analyzed. Systolic blood pressure (SBP) significantly increased during freezing (138.7±28.0 to 148.0±27.2 mm Hg, P<0.001) and sharply dropped (136.3±26.0 to 95.0±17.9 mm Hg, P<0.001) during a mean of 21.0±8.0 seconds after releasing the occlusion during thawing. In the multivariate analyses, the left PVs (P=0.008) and lower baseline SBP (P<0.001) correlated with a larger SBP rise, whereas a higher baseline SBP (P<0.001), left PVs (P=0.017), lower balloon nadir temperature (P=0.027), and female sex (P=0.045) correlated with larger SBP drops. These changes were similarly observed regardless of preprocedural atropine administration and the target PV order. PV occlusions without freezing exhibited no SBP change. PV antrum freezing without occlusions similarly increased the SBP, but the SBP drop was significantly smaller than that with occlusions (P<0.001). The SBP drop time-course paralleled the left ventricular ejection fraction increase (66.8±8.1% to 79.3±6.7%, P<0.001) and systemic vascular resistance index decrease (2667±1024 to 1937±513 dynes-sec/cm2 per m2, P=0.002). CONCLUSIONS: With second-generation cryoballoon-based PV isolation, SBP significantly increased during freezing owing to atrial tissue freezing and dropped sharply after releasing the occlusion, presumably because of the peripheral vascular resistance decrease mainly by circulating chilled blood.

A case of ventricular fibrillation as a consequence of capecitabine-induced secondary QT prolongation: A case report.

Capecitabine is an oral fluoropyrimidine which can prolong QT interval. However, there have been no reports that capecitabine induced ventricular fibrillation (VF) due to secondary QT prolongation in patients with no structural heart disease. A 39-year-old woman developed VF during the chemotherapy of capecitabine for colon cancer. At the administration, corrected QT interval (QTc) was prolonged to 559 ms despite no evidence of organic heart disease. Discontinuation of capecitabline normalized the QTc (414 ms). During the follow-up of eight years, neither the QTc prolongation nor the recurrent VF has been detected. We report the rare case of capecitabine-related VF without any organic heart disease. .

The mechanism of mitral regurgitation assessed by preprocedural echocardiography is associated with the outcome of catheter ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: Mitral regurgitation (MR) is generally classified as either primary (organic) or secondary (functional). Although patients with atrial fibrillation (AF) often exhibit MR, the relation between the etiology of MR and the outcome of catheter ablation (CA) remains unknown. We conducted this study in order to elucidate this association. METHODS: Among 1330 consecutive paroxysmal AF patients who underwent initial catheter ablation in our institution, 92 patients (62 men, mean age 65 ± 7 years) who had moderate or severe MR were included in this study; 46 were classified to have primary and the remaining 46 to have secondary MR by preoperative echocardiography. These patients were prospectively monitored after the CA. RESULTS: During a mean follow-up period of 27.9 ± 28.8 months, AF recurred in 26/46 (56.6 %) of primary MR patients and in 15/46 (32.6 %) of those with secondary MR (P < 0.02). Although univariate analysis found that diabetes, left atrial volume indexed by body surface area (LAVI), and primary MR were significantly associated with AF recurrence, primary MR (hazard ratio (HR), 2.47; 95 % confidence interval (CI), 1.30-4.88; P = 0.006) and LAVI (HR, 1.03/1 mL/m(2) increase; 95 % CI, 1.00-1.06; P = 0.03) remained significant predictors on multivariate analysis. The AF recurrence-free rate was lower in patients with primary MR after both the initial and final CA. CONCLUSION: In patients with paroxysmal AF and moderate or severe MR, primary MR may increase the risk of AF recurrence after the initial and final CA.

Rapid Mapping of Right Atrial Tachycardia Using a New Multielectrode Basket Catheter.

INTRODUCTION: The mapping of atrial tachycardia (AT) can often be challenging and time-consuming, especially in patients with ATs that develop following cardiac surgery or are concomitant with atrial fibrillation. Recently, a new multielectrode basket catheter (MBC) has become available; we hypothesized that the MBC could be utilized to diagnose AT circuits. METHODS AND RESULTS: This study included 51 consecutive patients undergoing catheter ablation of clinically documented right-sided ATs (including 17 cases following cardiac surgery). Using a NavX system, 2 activation maps of the ATs were created, one using the new MBC (32 mm, 31 poles) and the other using a circular catheter. The time needed to complete the activation maps and the points acquired with both mapping catheters were compared. In all 64 ATs, including 34 non-cavotricuspid isthmus-dependent ATs, the AT activation maps created by both catheters were essentially identical. The number of points acquired to complete the activation maps did not differ significantly between the MBC and the circular catheter (387 [285-511] vs. 374 [269-533], P = 0.19), but the mapping time was significantly shorter using the MBC (4.0 [3.0-6.0] minutes vs. 8.0 [6.5-10.0] minutes, P < 0.0001). Inadvertent mechanical AT termination (n = 6) was observed only during mapping with the circular catheter. CONCLUSION: In patients with right-sided ATs, the use of an MBC could save mapping time.

Impact of Non-Pulmonary Vein Foci on the Outcome of the Second Session of Catheter Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (AF) is primarily triggered by pulmonary veins (PVs). However, non-PV AF foci may also trigger AF. METHODS: We examined 207 patients (mean age, 62 ± 11 years; 166 men) who underwent a second catheter ablation (CA) and evaluated the clinical significance of non-PV AF foci on the outcomes. RESULTS: Electrical reconnections between the PVs and left atrium (LA) were observed in 162 patients (78.3%). Non-PV AF foci were identified in 95 patients (45.9%, 60 patients with successfully ablated non-PV AF foci and 35 with unmappable non-PV AF foci). During a median follow-up period of 22.7 months, 61 patients (29.5%; 18/112 [16.1%] without non-PV AF foci vs. 20/60 [33.3%] with successfully ablated non-PV AF foci vs. 23/35 [65.7%] with unmappable non-PV AF foci, P < 0.0001) developed AF recurrence; 52 (85.2%) developed recurrence within 1 year. The presence of non-PV AF foci was a significant clinical predictor of AF recurrence after the second CA; successfully ablated non-PV AF foci increased the AF recurrence risk by 2.24 times (95% confidence interval [CI], 1.12-4.54; P = 0.02), and unmappable AF foci increased this risk by 5.58 times (95% CI, 2.73-11.63; P < 0.0001). CONCLUSION: Nearly half of the patients had non-PV AF foci at the second CA session. AF recurred after the second CA session in approximately 30%, with most recurrences happening within 1 year. The presence of non-PV AF foci significantly increased the AF recurrence risk after a second CA. When non-PV AF foci were unmappable, the AF recurrence rate was extremely high.

Incidences of esophageal injury during esophageal temperature monitoring: a comparative study of a multi-thermocouple temperature probe and a deflectable temperature probe in atrial fibrillation ablation.

PURPOSE: The study aim was to compare the incidence of esophageal injuries between different temperature probes in the monitoring of esophageal temperature during atrial fibrillation (AF) ablation. METHODS: One hundred patients with drug-resistant AF were prospectively and randomly assigned into two groups according to the esophageal temperature probe used: the multi-thermocouple probe group (n = 50) and the deflectable temperature probe group (n = 50). Extensive pulmonary vein (PV) isolation was performed with a 3.5-mm open irrigated tip ablation catheter by using a radiofrequency (RF) power of 25-30 W. In both groups, the esophageal temperature thermocouple was placed on the area of the esophagus adjacent to the ablation site. When the esophageal temperature reached 42 °C, the RF energy delivery was stopped. Esophageal endoscopy was performed 1 day after the catheter ablation. RESULTS: No differences existed between the two groups in terms of clinical background and various parameters related to the catheter ablation, including RF delivery time and number of RF deliveries at an esophageal temperature of >42 °C. Esophageal lesions, such as esophagitis and esophageal ulcers, occurred in 10/50 (20 %) and 15/50 (30 %) patients in the multi-thermocouple and deflectable temperature probe groups, respectively (P = 0.25). Most lesions were mild to moderate injuries, and all were cured using conservative treatment. CONCLUSION: The incidence of esophageal injury was almost equal between the multi-thermocouple temperature probe and the deflectable temperature probe during esophageal temperature monitoring. Most of the esophageal lesions that developed during esophageal temperature monitoring were mild to moderate and reversible.