Chinese expert consensus on the construction of the fluoroless cardiac electrophysiology laboratory and related techniques.

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab.

Direct autotransfusion in the management of acute pericardial tamponade during catheter ablation for atrial fibrillation: An imperfect but practical method.

Background: Acute pericardial tamponade (APT) is one of the most serious complications of catheter ablation for atrial fibrillation (AF-CA). Direct autotransfusion (DAT) is a method of reinjecting pericardial blood directly into patients through vein access without a cell-salvage system. Data regarding DAT for APT are rare and provide limited information. Our present study aims to further investigate the safety and feasibility of DAT in the management of APT during the AF-CA procedure. Methods and results: We retrospectively reviewed 73 cases of APT in the perioperative period of AF-CA from January 2014 to October 2021 at our institution, among whom 46 were treated with DAT. All included patients successfully received emergency pericardiocentesis through subxiphoid access guided by X-ray. Larger volumes of aspirated pericardial blood (658.4 ± 545.2 vs. 521.2 ± 464.9 ml), higher rates of bridging anticoagulation (67.4 vs. 37.0%), and surgical repair (6 vs. 0) were observed in patients with DAT than without. Moreover, patients with DAT were less likely to complete AF-CA procedures (32/46 vs. 25/27) and had a lower incidence of APT first presented in the ward (delayed presentation) (8/46 vs. 9/27). There was no difference in major adverse events (death/disseminated intravascular coagulation/multiple organ dysfunction syndrome and clinical thrombosis) (0/0/1/0 vs. 1/0/0/0), other potential DAT-related complications (fever/infection and deep venous thrombosis) (8/5/2 vs. 5/3/1), and length of hospital stay (11.4 ± 11.6 vs. 8.3 ± 4.7 d) between two groups. Conclusion: DAT could be a feasible and safe method to deal with APT during AF-CA procedure.

Multimorbidity, polypharmacy and inappropriate prescribing in elderly patients with atrial fibrillation: A report from the China Atrial Fibrillation Registry Study.

Background: Multimorbidity, polypharmacy and inappropriate prescribing is common in elderly patients worldwide. We aimed to explore the current status of multimorbidity, polypharmacy and the appropriateness of pharmacological therapy among elderly patients with atrial fibrillation (AF) in China. Materials and methods: We randomly selected 500 patients aged 65 years or older from the China AF Registry study. Multimorbidity was defined as ≥2 comorbidities and polypharmacy was defined as ≥5 long-term prescribed drugs. Appropriateness of prescribing was evaluated using the Screening Tool of Older People's Prescriptions/Screening Tool to Alert to Right Treatment (STOPP/START) criteria version 2. Patients' attitudes toward polypharmacy were evaluated by the Patients' Attitudes Towards Deprescribing (PATD) questionnaire. Results: Among the 500 patients included (mean age 75.2 ± 6.7 years, 49.0% male), 98.0% had multimorbidity and 49.4% had polypharmacy. The prevalence of potentially inappropriate medications (PIMs) and potential prescribing omissions (PPOs) was 43.6% (n = 218) and 71.6% (n = 358), respectively. Traditional Chinese medicine attributed largely to PIMs. Anticoagulants were the most common PPOs. Many clinical factors increased the risk of PIMs and PPOs. However, polypharmacy increased the risk of PIMs (OR 2.70, 95%CI 1.78-4.11; p < 0.0001), but not PPOs. In addition, 73.7% patients with polypharmacy were willing to have one or more of their medications prescribed if advised by their doctor. Conclusion: Multimorbidity and polypharmacy were highly prevalent in elderly patients with AF in China. A high prevalence of inappropriate prescribing was also observed. Therefore, much more attention should be paid to the serious health problem in the elderly population.

Right free-wall accessory pathway with branched atrial insertions: Clinical, electrocardiographic, and electrophysiological characteristics.

BACKGROUND: Right free-wall (RFW) accessory pathway (AP) with branched atrial insertions is a rare, underrecognized AP that may be associated with initial ablation failure. OBJECTIVE: The purpose of this study was to investigate the clinical and electrophysiological characteristics of this AP. METHODS: From January 2011 to March 2018, 10 patients identified with branched RFW-AP were enrolled in this study, and 30 consecutive patients with conventional RFW-APs served as control group. Right atrium (RA) was activation-mapped and 3-dimensionally reconstructed during AP-mediated orthodromic tachycardia or right ventricular pacing. Atrial insertions were defined as the earliest breakout sites, and their relationship with the tricuspid annulus (TA) were described and analyzed. RESULTS: An average of 3 separate atrial insertions on the atrial side were documented among these 10 cases (5 female and 5 male; mean age 38.0 ± 13.9 years). All atrial insertions were away from the TA. The nearest atrial insertions averaged 15.9 ± 3.4 mm away from the TA, and the farthest atrial insertions were 22.6 ± 5.7 mm away from the TA. Anterograde and retrograde AP conduction remained unaffected after ablation of the first earliest breakout site but were eliminated by ablating all insertions after an average of 2.5 (range 2-2.5) remaps, 3 sites of ablation (range 2.5-4.5), 21 (range 15.5-37.8) radiofrequency applications, and 659.5 (range 464.3-1144.3) seconds of radiofrequency ablation duration. After 12-month follow-up, no patients reported AP conduction recovery or recurrent tachycardia. CONCLUSION: RFW-AP with branched atrial insertions is an atypical AP variant and featured by >1 distinct atrial insertions on atrial side. Stepwise ablation rather than single focal ablation is required to eliminate all retrograde conduction.

Right atrial diameter and outcome of catheter ablation of atrial fibrillation.

PURPOSE: While AF is considered more like a left atrial (LA) disease, to what extent the right atrium contributes to the pathogenesis and ablation outcome of AF remains unclear. This study aimed to identify if right atrial diameter (RAD) could predict arrhythmia recurrence after catheter ablation of atrial fibrillation (AF). METHODS: Four hundred and seventy patients with drug-resistant AF [paroxysmal AF (PAF) 196; non-PAF 274] who underwent primary catheter ablation were enrolled. Ablation strategy included complete bilateral pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, LA roof, and tricuspid isthmus in non-PAF cases. Risk factors associated with recurrence were determined by a Cox regression model, and the predictive power was evaluated by using receiver operating characteristic curve. RESULTS: After 24.3 ± 18.0 months, 284 patients (60.6%) experienced atrial tachyarrhythmia recurrence (111 in PAF, 173 in non-PAF). RAD was moderately associated with LA diameter (r = 0.371, P < 0.001), left ventricular ejection fraction (r = -0.205, P < 0.001), and left ventricular end-diastolic diameter (r = 0.319, P < 0.001). Multivariate Cox regression analysis demonstrated that RAD was an independent predictor for recurrence only in PAF patients with LAD ≥35 mm (HR 1.044, 95% CI 1.007-1.082, P = 0.021). The RAD cutoff value of 35.5 mm predicts atrial tachyarrhythmia recurrence with 85.4% sensitivity and 29.2% specificity. Kaplan-Meier analysis indicated that RAD over 35.5 mm is associated with more recurrence after PAF ablation (log-rank P = 0.034), comparing to those with RAD <35.5 mm. CONCLUSIONS: RAD predicts outcome of ablation only in patients with PAF and concurrent LA enlargement. Under this condition, RAD <35.5 mm is associated with a more favorable recurrence-free survival at over 2-year follow-up.

Prospective randomized comparison between a fixed '2C3L' approach vs. stepwise approach for catheter ablation of persistent atrial fibrillation.

AIMS: This prospective clinical trial was designed to evaluate the efficacy of an ablation strategy, namely '2C3L', in the treatment of persistent atrial fibrillation (AF); and to compare its efficacy with that of the 'stepwise' approach, which has been acknowledged as a promising ablation technique for persistent AF. METHODS AND RESULTS: The '2C3L' technique is a fixed ablation approach consisting of bilateral circumferential pulmonary vein antrum isolation (PVAI) and three linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavo-tricuspid isthmus. One hundred and forty-six patients with persistent AF were randomized to undergo ablation by using the '2C3L' or the 'stepwise' technique (n = 73, respectively). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drug (AAD) after a single procedure at follow-up. Twelve months after a single procedure, there was no difference in sinus rhythm (SR) maintenance rate between the two groups (67% for '2C3L' vs. 60% for 'stepwise', P = 0.394; 95% confidence interval of between-group difference -8.7 to 22.4%). The procedure (222 ± 42 vs. 263 ± 41 min), fluoroscopy (41 ± 9 vs. 55 ± 8 min), and radiofrequency (RF) (107 ± 32 vs. 128 ± 38 min) time were significantly shorter in the '2C3L' group (all P < 0.001). At 25 ± 5 months after the first procedure, 57.5 and 52.1% of patients from the '2C3L' group and the 'stepwise' group were in SR off AAD (P = 0.494), respectively. CONCLUSIONS: For catheter ablation of persistent AF, the '2C3L' strategy is a fixed approach associated with clinical efficacy similar to that of the 'stepwise' approach but with less RF delivery, fewer X-ray exposure, and shorter procedural time.

Impact of CHA2DS2 VASc score on substrate for persistent atrial fibrillation and outcome post catheter ablation of atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore if CHA2DS2 VASc score can predict substrate for persistent atrial fibrillation ( AF) and outcome post catheter ablation of AF.</p><p><b>METHODS</b>From January 2011 to December 2012,116 patients underwent catheter ablation of persistent AF in our department and were enrolled in this study. CHA2DS2VASc score was calculated as follows: two points were assigned for a history of stroke or transient ischemic attack and age ≥ 75 and 1 point each was assigned for age ≥ 65, a history of hypertension, diabetes,recent cardiac failure, vessel disease, female. Left atrial geometry ( LA) was reconstructed with a 3.5 mm tip ablation catheter with fill-in threshold 10 in CARTO system. The mapping catheter was stabled at each endocardial location for at least 3 seconds for recording. The electrogram recordings at each endocardial location were analyzed with a custom software embedded in the CARTO mapping system. Interval confidence level (ICL) was used to characterize complex fractionated atrial electrograms (CFAEs) . As the default setting of the software, ICL more than or equal to 7 was considered sites with a highly repetitive CFAEs complex. CFAEs index was defined as the fraction of area of ICL more than or equal to 7 to the left atrial surface. The CFAEs index and outcome of catheter ablation among different CHA2DS2VASc groups were compared.</p><p><b>RESULTS</b>Of the 116 patients, CHA2DS2VASc was 0 in 33 patients, 1 in 31 patients and ≥ 2 in 52 patients. Left atrial surface ((121.2 ± 18.9) cm2, (133.6 ± 23.8) cm2, (133.9 ± 16.1) cm2, P = 0.008), left atrial volume ((103.6 ± 24.8) ml, (118.3 ± 27.8) ml, (120.9 ± 20.9) ml, P = 0.005) and CFAEs index (44.6% ± 22.4%, 54.2% ± 22.2%, 58.7% ± 23.1%, P = 0.023) increased in proportion with increasing CHA2DS2VASc. ICLmax, ICLmin and CFAEs spatial distribution were similar among the three groups. During the mean follow-up of (13 ± 8) months, the recurrence rate were 36.4%, 35.5%, 55.8% among the three groups (P = 0.025).</p><p><b>CONCLUSION</b>A high CHA2DS2VASc score is associated with extensive AF substrate and higher recurrence rate post catheter ablation of persistent AF.</p>

Predictors of recurrence after a repeat ablation procedure for paroxysmal atrial fibrillation: role of left atrial enlargement.

AIMS: This study sought to explore the predictors of recurrence in patients with paroxysmal atrial fibrillation (AF) undergoing repeat catheter ablation, especially the impact of left atrial (LA) remodelling after the original procedure on the outcome of repeat procedure. METHODS AND RESULTS: Ninety-five patients undergoing repeat ablation were enrolled in this study. Repeat procedure endpoints were pulmonary vein isolation, linear block when linear ablation is performed, and non-inducibility of atrial tachyarrhythmia by burst pacing. Patients with LA enlargement between the pre-original procedure and pre-repeat procedure were categorized as Group 1 (35 patients), while individuals with no change or decrease of LA diameter were categorized as Group 2 (60 patients). The mean duration from the original procedure to the repeat procedure was 12 months (1-40 months). After 29.6 ± 20.5 (3-73) months follow-up from the repeat procedure, 33 patients experienced recurrence (34.7%). The recurrence rate was significantly higher in Group 1 than in Group 2 (51.4 VS. 25.0%, P = 0.017). In univariate analysis, LA remodelling was the only predictor of recurrence. In multivariate analysis, after adjustment for age and LA diameter, Group 1 had a greater risk of recurrence after the repeat procedure (hazard ratio = 2.22, 95% confidence interval: 1.02-4.81, P = 0.043). CONCLUSIONS: Left atrial enlargement after undergoing the original catheter ablation of paroxysmal AF was an independent risk factor of recurrence after repeat ablation.

Ablation of left-sided accessory pathways with atrial insertion away from the mitral annulus using an electroanatomical mapping system.

BACKGROUND: A left-sided accessory pathway (AP) with atrial insertion away from the mitral annulus (MA) may result in difficulty or failed ablation along the MA. We report our initial experience of ablating this rare form of AP by a 3-dimensional electroanatomical mapping system (CARTO). METHODS: From January 2007 to August 2011, 29 patients with left-sided APs who failed previous ablations in other centers were enrolled in this study. Left atrium (LA) was reconstructed during orthodromic atrioventricuar reentry tachycardias (AVRTs) or ventricle pacing by using a 3-dimensional electroanatomical mapping system. The AP atrial insertion was defined as the earliest retrograde atrial activation and successful ablation of the AP at the site. RESULTS: Among the 29 patients who had failed previous ablation, 7 patients were found to have atrial insertions away from the MA. Out of the 7 patients, atrial insertions were at the base of the LA appendage in 5 patients and at the anterior roof of LA in 2 patients. Ablation at the atrial insertion successfully abolished AP conduction. The mean distance between the atrial insertion sites and the MA was 24.9 ± 4.9 mm. No patients reported recovered AP conduction or recurrent tachycardias after at least 12-month follow-up. CONCLUSIONS: Left-sided APs may have atrial insertions away from the MA. By using the CARTO system, atrial insertions can be reliably identified and ablated.

Impact of different termination modes on atrial fibrillation termination in catheter ablation of persistent atrial fibrillation.

BACKGROUND: The optimal endpoint for catheter ablation of persistent atrial fibrillation (AF) remains ambiguous. This study investigated the impact of AF termination as a procedural endpoint and the termination mode on long-term clinical outcome. METHODS: Two hundred and ninety-three patients who underwent stepwise ablation for persistent AF were categorized into the AF termination by ablation group and into the electrical cardioversion (CV) group. Subgroups were also analyzed based on different termination modes. Follow-up assessment included early recurrence and sinus rhythm (SR) maintenance. RESULTS: During initial ablation, 33 patients (11.3%) were directly converted to SR, 166 patients (56.7%) were converted to atrial tachycardia (AT) that subsequently restored SR with further ablation in 98 patients (33.4%), and a total of 162 patients (55.3%) underwent cardioversion due to persistent atrial arrhythmias. Comparison between termination by ablation and termination by cardioversion in patients exhibiting AF or AT revealed that no significant difference was observed in early recurrence (38.2% vs. 43.8%, P = 0.328) and SR maintenance (67.2% vs. 59.8%, P = 0.198) during the (23 ± 7) months follow-up. Even after repeat ablation, the SR maintenance continued to exhibit no statistical difference in above two groups (72.5% vs. 70.4%, P = 0.686). Further analysis of subgroups, however, demonstrated that patients with AF terminated directly to SR experienced better clinical outcomes than other subgroups (P < 0.05). Furthermore, atrial arrhythmias present during ablation have been implicated in prediction of recurrence mode: AF or AT (P < 0.05). CONCLUSIONS: Termination as a procedural endpoint is not associated with favorable long-term SR maintenance in persistent AF. AF methods that convert arrhythmia directly to SR have, however, been linked with improved clinical outcomes, although conversions to AT may not be correlated. Atrial arrhythmias observed during the ablation may be used to predict the recurrence mode.

A new method to evaluate linear block at the left atrial roof: is it reliable without pacing?

OBJECTIVE: The present study aimed to evaluate a new method for validation of complete linear block at the left atrial (LA) roof. BACKGROUND: Linear lesions at the LA roof have been reported to improve the success rate of catheter ablation of atrial fibrillation (AF). METHODS: Complete linear block at the LA roof was evaluated in 31 patients after complete isolation of pulmonary vein antrum (PVA) using a simple method. We hypothesized that complete linear block of the LA roof could be confirmed during sinus rhythm if (1) a continuous line of double potentials could be recorded at the LA roof, and (2) the activation sequence along the posterior wall changed to caudocranial. The results of this method were compared with standard pacing techniques. RESULTS: Thirty-nine lines were assessed using this method: 8 before and 31 after achievement of complete conduction block. After validation of complete linear block at the LA roof, double potentials with a mean interpotential interval of 60 +/- 13 ms were recorded in 25 patients and electroanatomical mapping of the left atrium showed the activation sequence of posterior wall changed to caudocranial in all 31 patients during sinus rhythm. The sensitivity, specificity, positive and negative predictive values of this method for validating complete linear block were 100%, 88.9%, 96.8%, and 100%, respectively. CONCLUSION: A corridor of double potentials along the roof line and a caudocranial activation sequence along the posterior wall during sinus rhythm can indicate conduction block at the LA roof after PVA isolation.