Clinical efficacy of irrigated catheter application of amiodarone during ablation of persistent atrial fibrillation

[Amiodarone promotes heat-induced apoptosis, inflammation and oxidative stress in mouse HL1 atrial myocytes]

OBJECTIVE

To investigate the injury types of atrial myocytes induced by heat exposure and the effect of amiodarone on heat-induced injuries in atrial myocytes.

OBJECTIVE

The optimal temperature for heat exposure and optimal concentration of amiodarone were determined by measuring the cell viability exposed to different temperatures and different concentrations of amiodarone. Heat exposure of HL1 atrial myocytes was conducted using a water bath, and the effect of amiodarone on cell viability was assessed with MTS method; cell apoptosis was detected using flow cytometry, and the levels of IL-1β, IL-6, TNF-α, SOD and MDA were detected with enzyme-linked immunosorbent assay (ELISA).

OBJECTIVE

Compared with the blank control cells, the cells exposed to a temperature of 52 ℃ showed a significantly decreased survival rate and a lowered SOD activity (P < 0.001) with increased IL-1β and MDA levels (P < 0.01) and markedly increased apoptosis rate and IL-6 level (P < 0.001). Compared with the heat exposure group, amiodarone resulted in significantly decreased survival rate of the atrial myocytes (P < 0.01), obviously decreased SOD activity (P < 0.05), and increased cell apoptosis rate (P < 0.05) and IL-1β, IL-6, MDA and TNF-α levels (P < 0.01 or 0.001).

OBJECTIVE

Heat exposure induces apoptosis, inflammation and oxidative stress in mouse HL1 atrial myocytes, and amiodarone can enhance the effects of heat exposure to aggravate the cell injuries.

Comparative effects of intensive ganglionated plexus ablation in treating paroxysmal atrial fibrillation and vasovagal syncope

BACKGROUND

Ganglionated plexus (GP) ablation is used to treat atrial fibrillation (AF) and vasovagal syncope (VVS). However, the comparative effects of GP ablation in treating paroxysmal atrial fibrillation (PAF) and VVS have not been well studied.

OBJECTIVE

The purpose of this study was to investigate the effects of intensive GP ablation on PAF and VVS.

METHODS

PAF and VVS patients were enrolled in this study. Pulmonary vein isolation (PVI) was performed in the PAF group, and additional ablation was performed at GP sites. Anatomic ablation of left atrial GPs was performed in the VVS group. The primary endpoint was freedom from AF or other sustained atrial tachycardia and syncope recurrence.

RESULTS

A total of 195 patients were enrolled: 146 patients with PAF, including eight patients with combined VVS (PAF group), and 49 patients with VVS (VVS group). Vasovagal response (VR) was achieved in 78 (53.4%) patients in the PAF group and 48 patients (98.0%) in the VVS group (P < .05). During the 17.8 ± 10.5 (range, 3-42) month follow-up, 126 (86.3%) patients were free of AF in the PAF group, and 45 (91.8%) patients in the VVS group had no syncope recurrence and significantly improved symptoms.

CONCLUSIONS

Anatomically guided intensive GP ablation showed efficient clinical outcomes for both groups of patients. Compared with PAF patients, VVS patients had more VR during ablation in the left atrium. Furthermore, VR during ablation indicated a better prognosis in PAF patients.

Remote ischaemic preconditioning ameliorates sinus rhythm restoration rate through Cox maze radiofrequency procedure associated with inflammation reaction reduction

Remote ischaemic preconditioning (RIPC) as adjuvant to selective heart surgery attenuates cardiac injury and atrial fibrillation (AF) occurrence. We investigated its effect on sinus rhythm (SR) restoration rate in permanent AF patients undergoing Cox maze (CM) radiofrequency ablation with concomitant mitral valve surgery. From May 2013 to May 2017, 206 patients with rheumatic valve disease concomitant with permanent AF were randomized to receive prosthesis valve replacement and CM radiofrequency ablation procedure with (n = 104) or without (n = 102) RIPC (intermittent arm ischaemia through three cycles of 5-min inflation, followed by 5-min deflation of a blood pressure cuff). The primary end point of the study was freedom from cumulative AF without using antiarrhythmic drugs 1 year after operation; the secondary end points included inflammation reaction index over 48 h postoperatively and clinical outcomes. Baseline characteristics and preoperative data did not differ between groups. The SR restoration rates were significantly higher in the RIPC group, 85.6%, 83.7%, and 82.7%, than those in the control group, 72.5%, 70.6%, and 69.6%, at discharge, 6 months and 12 months, respectively, after the radiofrequency ablation procedure (P < 0.05). The serum concentration of high sensitivity C-reactive protein and neutrophil-lymphocyte ratio were significantly decreased at 12 h, 24 h, and 48 h postoperatively in the RIPC group compared to those in the control group (P < 0.05). RIPC induced by brief ischaemia and reperfusion of the arm ameliorated SR restoration rate in patients with permanent AF through CM radiofrequency ablation procedure and was associated with reduction of postoperative systemic inflammation reaction index.

Clinical efficacy of irrigated catheter application of amiodarone during ablation of persistent atrial fibrillation

BACKGROUND

Pharmacological treatment during ablation of persistent atrial fibrillation (AF) is common, but utility of irrigated catheter application of amiodarone during ablation of persistent AF remains unclear.

HYPOTHESIS

Irrigated catheter application of amiodarone improves quality of ablation and long-term outcomes.

METHODS

We enrolled 90 persistent AF patients who underwent catheter ablation. Patients were randomized to the amiodarone group (n = 45) or control group (n = 45). All patients underwent stepwise ablation beginning with isolation of the pulmonary veins. Next, we performed ablation of linear lesions and focal triggers until sinus rhythm (SR) was achieved. The primary endpoint was documented atrial arrhythmia during follow-up. The secondary endpoint was cardioversion to SR during ablation.

RESULTS

All pulmonary veins were successfully isolated. Conversion of AF to SR occurred more frequently in the amiodarone group than in the control group (33 vs 23 [73.3% vs 51.1%]; P = 0.03). The amiodarone group had lower procedure, radiofrequency, and fluoroscopy times than the control group (167.4 ± 22.5 min vs 186.7 ± 25.3 min; 78.3 ± 14.2 min vs 90.4 ± 15.5 min; and 6.5 ± 1.9 min vs 8.6 ± 2.4 min, respectively; P < 0.05). More importantly, the atrial arrhythmia recurrence-free survival rates were 80% in the amiodarone group and 60% in the control group during the 14.7 ± 7.5-month follow-up (P = 0.043).

CONCLUSIONS

Irrigated catheter application of amiodarone during ablation for persistent AF resulted in higher cardioversion rates and lower procedure times and significantly reduced rates of atrial arrhythmia recurrence.