Weidong Meng

Procedural Arrhythmia Termination and Long-Term Single-Procedure Clinical Outcome in Patients with Non-paroxysmal Atrial Fibrillation

The influence of procedural arrhythmia termination on long‐term single‐procedure clinical outcome in patients with non‐paroxysmal atrial fibrillation (AF) remains controversial.

Right ventricular outflow pacing induces less regional wall motion abnormalities in the left ventricle compared with apical pacing.

AIMS This study aimed to explore if the right ventricular outflow tract (RVOT) pacing is superior to right ventricular apical (RVA) pacing on the overall left ventricular (LV) function and regional wall motion. METHODS AND RESULTS Sixty patients with atrio-ventricular (AV) block and normal ejection fraction undergoing dual-chamber pacemaker implantation were randomized to permanent ventricular stimulation either in the RVOT or the RVA. Left ventricular volume, ejection fraction, and LV regional wall motion were assessed by echocardiography. Right ventricular apical pacing had prolonged QRS duration, compared with RVOT pacing (154.1 ± 26.5 vs. 120.9 ± 22.3, P< 0.05). There were also significant differences in LV pre-ejection interval and interventricular mechanical delay (IVMD) at 12-month follow-up between the two groups, but none in the LV volume, left ventricular ejection fraction, and index of systolic synchrony (Ts-SD). During RVA pacing, the average peak systolic velocity (Sm) of 12 LV segments [3.5, 95% confidence interval (CI) 3.2-3.8 cm/s] had a trend of being lower compared with RVOT pacing (3.9, 95% CI 3.5-4.1 cm/s) (P= 0.09). Further analysis showed that the Sm at the inferior wall and posterior-septum wall was significantly decreased during RVA pacing compared with RVOT pacing. There were no significant differences for other LV segments. CONCLUSION The RVOT pacing in AV block patients over 1 year may be superior to RVA pacing in terms of regional LV performance, LV global electromechanical delay, and IVMD, although intraventricular dyssynchrony and LV volumes do not differ. Larger trials with clinical endpoints are warranted to conclusively define the advantages of RVOT or RV septal pacing.

A dual-loop bi-atrial macro-reentry flutter during atrial fibrillation ablation.

Dual-loop macro-reentry atrial flutter (AFL) is an atypical AFL, which has two loops of the reentry circuit usually localized within single atrium. In this case report, we present a double-loop bi-atrial flutter during atrial fibrillation ablation, in which the two reentry circuit loops were located around the inferior vena cava (IVC) and the mitral annulus, (MA) respectively.

Clinical implications of and factors influencing dissociated pulmonary vein potentials

BACKGROUND Factors influencing dissociated pulmonary vein (PV) potentials (DPVPs) in atrial fibrillation (AF) patients undergoing circumferential PV isolation have not been investigated. Furthermore, the clinical implications of such DPVPs remain controversial. METHODS Circumferential PV isolation as a first ablation procedure was performed in 688 consecutive patients with AF (460 men; mean age, 58.9±10.5 years). The clinical implications of and factors influencing DPVPs were evaluated. RESULTS Acute PV isolation was achieved in 679 (98.7%) patients. A total of 578 (42.6%) ipsilateral PVs with DPVPs were documented in 378 (55.7%) patients (DPVPs group). Multivariate analysis revealed that male gender [odds ratio (OR): 1.894; 95% confidence interval (CI): 1.344-2.667; p<0.001] and paroxysmal AF (OR: 1.715; 95% CI: 1.182-2.488; p=0.005) were independent factors for DPVPs. The incidence of acute and intraoperative PV reconnection (PVR) was higher in the DPVPs group than in the non-DPVPs group (33.1% vs. 17.9%; p<0.001 and 44.4% vs. 28.2%; p<0.001). After the first procedure, 244 (65.6%) DPVPs-group patients and 168 (56.4%; p=0.015) non-DPVPs group patients were free from AF recurrence. During repeat procedures, PVR incidence was similar in the DPVPs group (81.8%) and non-DPVPs groups (83.3%; p=0.863). CONCLUSION Male gender and paroxysmal AF were independent risk factors for DPVPs in patients undergoing circumferential PV isolation. DPVPs had a significant impact on acute and intraoperative PVR. The outcomes of the first ablation procedure were better in patients with DPVPs.

Comparison of circumferential pulmonary vein anatomy mapping guided by 3D mapping versus a mesh mapping catheter

Objective Catheter-based pulmonary vein isolation (PVI) is an established therapy for paroxysmal atrial fibrillation. The high-density mesh mapper (HDMM) guides circumferential PV-atrium isolation without the 3D electroanatomic mapping. This study aims to compare circumferential pulmonary vein (CPV) anatomy mapping between guiding by a 3D mapping system and the HDMM. Methods Forty-four consecutive patients with paroxysmal atrial fibrillation were scheduled for a first procedure for PVI. A CPV ostial anatomy map guided by HDMM was set up in the CARTO system while the operator was blinded to the CARTO screen. Then CARTO-guided ipsilateral PV maps were obtained and PVI was performed. This established another set of CPV ostial anatomy maps. The differences between the two mapping images were compared and analyzed. Results All 176 PVs in 44 patients could be mapped by both HDMM and CARTO. About 44.9% of the PV ostial anatomies were generally similar between the two different map images. The average point-to-point straight distance between the HDMM-guided map and the CARTO-guided map was 6.2 ± 1.4 mm. The area of the circumferential right PV (CRPV) in the HDMM map was larger than that in the CARTO map (P = 0.013). After a mean follow-up of 18.3 ± 4.3 months (6–24 months), 72.7% of patients (32/44) were free of atrial arrhythmia without anti-arrhythmic drugs (AADs). Conclusion Compared to the CARTO-guided CPV anatomy image, a highly similar figure could be achieved by mapping guided by the HDMM. (Clinical trial.gov number, ChiCTR-TNRC-11001390.)

SPATIAL TORSION OF THE IPSILATERAL SUPERIOR AND INFERIOR PULMONARY VEINS

Objectives We sought to evaluate the disregarded spatial torsion of the ipsilateral superior and inferior PVs. Methods Forty-eight consecutive atrial fibrillation patients, with four discrete PVs, were enrolled. Theostial plane of each PV, labelled by three landmarks on the CT image, was identified by three experienced observers respectively. Angle and distance between ostial planes were used to reach a consensus and to select the best ostial plane of each PV. A common ostial plane of the ipsilateral PV was computed using the two geometric centers of each side PVs and the axial centre of the two geometric centres. The torsionangle was defined as the absolute difference of the two dihedral angles between the common ostial plane and the best ostial plane of the superior and inferior PVs. Results The torsion angle >15° was found in 16 left PVs (16/48) and in 9 right PVs (9/48, p=0.104). Moreover, in two cases (2.1%), the torsion angle exceeded 30° (1 left PVs and 1 right PVs). The torsion angleof the left PVs was significant greater than that of the right PVs (13.65±5.90 vs 10.61±5.96, p=0.014). Conclusions There was a significant torsion between the ipsilateral PVs, which should be taken into account when physicians plan their ablation to avoid a single-plane circumferential ablation.

CARTO-MERGE CAN IMPROVE THE ABLATION ACCURACY FOR PULMONARY VEIN ISOLATION

Objectives To quantify the superiority of performing AF ablation guidedby CARTO-Merge. Methods Forty-eight consecutive AF patients, with four discrete pulmonary veins (PVs), were enrolled. For the four separate PVs and the two ipsilateral PVs of each patient, three types of planes were defined respectively at the PV antrum. The fluoroscopy planes (FPs) were labelled in the CARTO under the guidance of contrast PVs angiography. After procedure, the ablation planes (APs) were defined with the ablation rings. The image planes (IPs) were labelled in the CT image. Results The angle between the APs and the IPs was significantly smaller than that between the FPs and the IPs with regard to the left inferior PV planes (15.80±7.64 vs 20.69±13.91, p=0.040) and the left superior PV planes (15.17±7.20 vs 23.21±12.97, p=0.001). Moreover, compared to that between the FPs and the IPs, less difference of angle and distance between the AP sand the IPs was demonstrated in the left PV planes (1.36±1.27 mm vs 2.89±2.49 mm, p<0.001; 13.91±6.20 vs 30.52±20.97, p<0.001), the right inferior PV planes (2.58±1.69 mm vs 3.51±2.46 mm, p<0.05; 13.58±8.01 vs 17.94±8.89, p=0.014), the right superior PV planes (2.10±1.80 mm vs 3.47±2.97 mm, p=0.009; 11.20±6.75 vs 33.38±15.86, p<0.001) and the right PV planes (2.33±1.71 mm vs 4.13±3.47 mm, p=0.002; 13.27±6.14 vs 26.40±18.89, p<0.001). Conclusions Navigation by CARTO-Merge, less difference of angle and distance between the ablation lesions and the actual PV ostia can be achieved, compared with the guidance of contrast PV angiography.

PULMONARY VEIN SPONTANEOUS ACTIVITIES: INFLUENCE FACTORS AND IMPACT ON PULMONARY VEIN RECONNECTION

Objectives In this study, we sought to evaluate the influence factors of pulmonary vein (PV) spontaneous activities (SAs) and the impact of SAs on the PV reconnection (PVR) in atrial fibrillation (AF) patients. Methods Circumferential PV isolation as a first ablation procedure was performed in 689 consecutive patients with AF (460 males, mean age 58.9±10.5 years). Results The acute PV isolation was achieved in 680 (98.7%) patients. A total of 342 ipsilateral PVs (25.1%, 342/1360) with SAs were documented in 295 patients (43.3%, 295/680). Patients were classified as SAs Group and Control Group. Univariate analysis revealed that gender (p=0.002), type of AF (p=0.006), rheumatic heart disease (p=0.002) and a history of cardiac surgery (p=0.008) had significant difference between the two groups. The multivariate analysis revealed that male (Exp [B]1.717, 95% CI 1.216 to 2.425, p=0.002) and paroxysmal AF (Exp (B) 1.595, 95% CI 1.145 to 2.221, p=0.006) were independently associated with the presence of SAs. The incidence of acute and intraoperative PVR of SAs Group was higher than that of Control Group (27.0% vs 19.0%, p=0.026; 38.6%vs 29.9%, p=0.042). Conclusions The male and paroxysmal AF were the two independently influence factors of SAs in patients under went circumferential PV isolation. The SAs had significant impact on the acute and intraoperative PVR during AF ablation.