Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?

BACKGROUND: Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation. METHODS: A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated. RESULTS: PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p < .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p < .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022). CONCLUSIONS: EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process. CONDENSED ABSTRACT: PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease.

BACKGROUND: Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD. METHODS: In total, 12,104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. RESULTS: Over a mean follow-up of 46.0 ± 18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0% vs. 41.9%, p = .03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9% vs. 31.2%;p = .04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], p = .03). The composite secondary endpoints were significantly higher in the SCAD group (12.70% vs. 8.54%, p = .02), mainly due to thromboembolism events (8.16% vs. 4.41%, p < .01). CONCLUSIONS: SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD.

Safety and efficacy of catheter ablation for atrial fibrillation in abdominal solid organ (renal and hepatic) transplant recipients: A single-center pilot experience.

BACKGROUND: Atrial fibrillation (AF) is common in abdominal solid organ transplant recipients and a cause of morbidity and mortality in this population. However, the outcomes of catheter ablation (CA) in transplant recipients with AF remain unclear. This study aimed to elucidate the outcomes of CA in renal and hepatic transplant recipients. METHODS AND RESULTS: Between 2015 and 2019, 14 transplant recipients (nine with kidney transplantation and five with liver transplantation) were enrolled from among 10,741 AF patients and underwent CA at Anzhen Hospital. Another 56 patients matched by age, sex, and AF type were selected as the control group (four controls for each transplant recipient). During a mean follow-up of 30.0 ± 13.3 months after the initial procedure, 10 (71.4%) of the transplant patients, compared to 41 (73.2%) of the control patients, remained free from AF recurrence (p = 1.000). A repeated procedure was performed in one transplant patient and in six control subjects. Consequently, 11 (78.6%) of the transplant patients, compared to 46 (82.1%) of controls, were in sinus rhythm after the repeated ablation (p = .715). Notably, Kaplan-Meier analysis did not demonstrate any significant differences in the atrial arrhythmia-free rate after the initial and repeated procedure between the two groups. Vascular complications were identified in one transplant patient and two control subjects, while no life-threatening complications were observed in either group. There was no transient allograft dysfunction in transplant recipients after CA. CONCLUSION: CA is safe and effective in abdominal solid transplant recipients, and maybe an optimal therapeutic strategy for this group.

Ablation of right-sided accessory pathways with atrial insertion far from the tricuspid annulus using an electroanatomical mapping system.

BACKGROUND: It is difficult to ablate a right-sided accessory pathway (AP) with atrial insertion far from the tricuspid annulus (TA). We report our initial experience of ablating this rare AP by a 3-dimensional electroanatomical mapping system (CARTO). METHODS: From January of 2006 to April of 2008, 18 patients with right-sided APs who failed previous outside ablations were enrolled in this study. Retrograde AP conduction was mapped during pacing at the right ventricular apex by activation-mapping the right atrium (RA) using a 3-dimensional electroanatomical mapping system. AP atrial insertion was defined as the earliest retrograde atrial activations and successful ablation of the APs at this site. RESULTS: Among the 18 patients who had failed previous ablation, 10 patients (7 patients with right manifest APs and 3 patients with right conceal APs) had atrial insertions far from the TA. Of the 10 patients, the atrial insertions were found at the base of the RA appendage in 3 patients, at the high lateral RA in 5 patients, at the low lateral RA in other 2 patients. Ablation at the atrial insertions successfully abolished the AP conduction. The mean distance between the atrial insertion sites and the TA was 20.2 ± 2.7 mm. No patients reported recovered AP conduction or recurrent tachycardias after 6-month follow-up. CONCLUSIONS: The right-sided APs may have atrial insertion far from the TA. These uncommon variation of APs can be reliably identified and ablated using CARTO system.

Sinus node injury as a result of superior vena cava isolation during catheter ablation for atrial fibrillation and atrial flutter.

BACKGROUND: The ectopic foci originating from superior vena cava (SVC) may act as triggers in the occurrence and perpetuation of atrial fibrillation (AF). Unfortunately, the SVC isolation may result in potential dysfunction of sinus node. Furthermore, little is known about the occurrence of sinus node injury complicated by the SVC isolation. METHODS: Patients with AF or atypical atrial flutter experienced SVC isolation. The junctional rhythm or sinus arrest could be observed, if sinus node was injured. Atropin and dopamine administration ruled out the vagal irritation of sinus node, when junctional rhythm or sinus arrest occurred. RESULTS: One hundred and thirty-two patients who had no electrocardiogram signs of sinus node dysfunction before ablation experienced the SVC isolation. Six patients (three men, three women, mean age 62.5 ± 8.6 years) had sinus node injury (4.5%, 6/132): four patients had junctional rhythm and one male patient had junctional rhythm and sinus arrest simultaneously; another male patient required AAI mode permanent pacemaker implantation due to the persistent junctional rhythm after SVC isolation. The ablation sites of all six patients closed to the junction of right atrium and SVC during the ablation of anterolateral free wall of the SVC. CONCLUSION: Sinus node may be damaged due to the ablation sites closer to sinus node. The definition of the junction of right atrium and SVC is very important, the ablation sites of anterolateral free wall of the SVC should not be too close to the SVC orifice.