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.

Acute conduction recurrence of mitral isthmus: Incidence, clinical characteristics, and implications.

BACKGROUND: Data on the incidence, clinical characteristics, and implications of acute conduction recurrence during mitral isthmus (MI) ablation are scarce. METHODS: MI ablation was performed in patients with atrial fibrillation. After confirming bidirectional conduction block, the acute conduction recurrence of MI was systematically evaluated. Clinical and electrophysiological characteristics were analyzed. RESULTS: A total of 66 consecutive patients in whom bidirectional conduction block of MI was achieved were prospectively enrolled in a single center. Acute conduction recurrence of MI developed in 12 (18.2%) patients within 14.2 ± 11.5 minutes after the confirmation of bidirectional conduction block. There were two recurrent conduction breakthrough sites of MI along the course of the great cardiac vein (4.5 ± 3.5 min) in two patients and 11 along the course of the ligament of Marshall (LOM) (16.0 ± 11.6 min, P = .035) in 11 patients. LOM accounted for most (84.6%, 11/13) acute MI conduction recurrence. MI length, total ablation time, and procedure time for MI were greater in patients with acute conduction recurrence than in those without acute conduction recurrence. During follow-up, arrhythmia recurrences were less observed in patients with acute conduction when compared to patients without acute conduction recurrence (0% vs 26.4%, P = .055). CONCLUSION: Acute conduction recurrence, predominantly due to recurrent LOM conduction, was a common phenomenon during MI ablation, and its evaluation should therefore be the focus to improve MI ablation efficacy and durability.

Ablation at Right Coronary Cusp as an Alternative and Favorable Approach to Eliminate Premature Ventricular Complexes Originating From the Proximal Left Anterior Fascicle.

BACKGROUND: Premature ventricular complex (PVC) with narrow QRS duration originating from proximal left anterior fascicle (LAF) is challenging for ablation. This study was performed to evaluate the safety and feasibility of ablation from right coronary cusp (RCC) for proximal LAF-PVC and to investigate this PVC's characteristics. METHODS: Mapping at RCC and left ventricle and ECG analysis were performed in 20 patients with LAF-PVC. RESULTS: The earliest activation site (EAS), with Purkinje potential during both PVC and sinus rhythm, was localized at proximal LAF in 8 patients (proximal group) and at nonproximal LAF in 12 patients (nonproximal group). The Purkinje potential preceding PVC-QRS at the EAS in proximal group (32.6±2.5 ms) was significantly earlier than that in nonproximal group (28.3±4.5 ms, P=0.025). Similar difference in the Purkinje potentials preceding sinus rhythm QRS at the EAS was also observed between proximal and nonproximal groups (35.1±4.7 versus 25.2±5.0 ms, P<0.001). In proximal group, the distance between the EAS to left His bundle and to RCC was shorter than that of nonproximal group (12.3±2.8 versus 19.7±5.0 mm, P=0.002, and 3.9±0.8 versus 15.7±7.8 mm, P<0.001, respectively). No difference in the distance from RCC to proximal LAF was identified between the 2 groups. PVCs were successfully eliminated from RCC for all proximal groups but at left ventricular EAS for nonproximal groups. The radiofrequency application times, ablation time, and procedure time of nonproximal group were longer than that of proximal group. Electrocardiographic analysis showed that, when compared with nonproximal group, the PVCs of proximal group had narrower QRS duration; smaller S wave in leads I, V5, and V6; lower R wave in leads I, aVR, aVL, V1, V2, and V4; and smaller q wave in leads III and aVF. The QRS duration difference (PVC-QRS and sinus rhythm QRS) <15 ms predicted the proximal LAF origin with high sensitivity and specificity. CONCLUSIONS: PVCs originating from proximal LAF, with unique electrocardiographic characteristics, could be eliminated safely from RCC.

A Practical Method for Ablation Catheter Reintroduction into the Left Atrium via Prior Transseptal Puncture, without Radiation.

BACKGROUND: We evaluated the feasibility and safety of reintroducing an ablation catheter (ABL) into the left atrium (LA) through a previously punctured interatrial septum under guidance of the show-catheter image-track function of the CARTO 3 3-dimensional (3D) electroanatomic mapping system. METHODS: One hundred consecutive paroxysmal or persistent drug-refractory atrial fibrillation (AF) patients (men: 55; mean age, 64.7 ± 12.1 years) who had undergone 2 fluoroscopy-guided transseptal punctures and anatomical LA reconstruction under CARTO 3-guidance, and required ABL reinsertion into the LA during mapping or ablation, were included. They were randomized 1:1 to the show-catheter (reintroduction under the CARTO 3 show-catheter image-track function) or fluoroscopy group (reintroduction under conventional fluoroscopy). RESULTS: Although the reconstructed 3D anatomy map was displaced in 21/100 patients (21.0%), the ABL was successfully reintroduced in all patients. In the show-catheter and fluoroscopy groups, model displacement incidence (18% versus 24%), tachyarrhythmias (46.0% versus 52.0%), complications (2% versus 4%), and number of ABLs reintroduced into the LA (3.3 ± 0.8 versus 3.1 ± 0.9) were similar (all P > .05). The show-catheter group displayed shorter ABL reintroduction time (9.5 ± 5.5 s versus 156.4 ± 35.5 s, P < .01), ABL reintroduction X-ray exposure time (0 s versus 39.3 ± 13.8 s, P < .01), and total X-ray exposure time (4.1 ± 1.4 min versus 4.7 ± 0.8, P < .05). CONCLUSION: During AF ablation, the catheter can be safely reintroduced into the LA, without additional fluoroscopy, under guidance of the CARTO 3 show-catheter image track function.

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.