BACKGROUNDDelayed cure had been observed in recurrent cases after index ablation of atrial fibrillation (AF), however, its mechanism and incidence have not been elucidated in detail. This study aims to investigate the impact of different ablation strategies on the incidence of delayed cure and its possible mechanisms after trans-catheter ablation of AF.

METHODSOne hundred and fifty-one consecutive cases with highly symptomatic, drug refractory AF were included in this study [M/F = 109/42, mean age (56.0 +/- 11.2) (18 - 79) years]. Segmental pulmonary vein ablation (SPVA) was performed in 83 patients with the guidance of circular mapping catheter (SPVA Group), circumferential PV linear ablation (CPVA) was carried out in the rest 68 cases under the guidance of 3 dimensional mapping system in conjunction with circular mapping catheter (CPVA Group). Delayed cure was defined as that early recurrence of atrial tachyarrhythmias (AF, atrial tachycardia, or atrial flutter) after ablation procedure was no longer observed during subsequent follow-up, and stable sinus rhythm was maintained > or = 2 months.

RESULTSEarly recurrence of atrial tachyarrhythmias was detected in 41 cases from SPVA group and 23 cases from CPVA group, and delayed cure occurred in 21.9% (9/41) of the cases from SPVA group and 47.8% (11/23) of the cases from CPVA group, more delayed cure in later group was observed (P < 0.05). Meanwhile, patients in SPVA group took a longer time to achieve a delayed cure [(27.0 +/- 18.0) days vs (14.0 +/- 8.1) days, P < 0.05], and presented more recurrent episodes [(3.50 +/- 1.08) times a week vs (2.42 +/- 1.11) times a week, P < 0.05]. However, recurrent episodes after index ablation were markedly decreased in cases with delayed cure from both groups (P < 0.05).

CONCLUSIONSDespite of an early recurrence of atrial tachyarrhythmias after index ablation of AF, delayed cure occurs in a significant number of patients undergoing either SPVA or CPVA. However, different ablation strategies place different impact on the delayed cure, more delayed cure is obtained with CPVA approach, and the delayed cure occurs earlier with this approach; the average recurrent episodes before delayed cure are also less frequently detected in CPVA group compared with those in SPVA group.

Adolescent ; Adult ; Aged ; Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Time Factors

OBJECTIVETo investigate the feasibility and efficacy of treating atrial fibrillation (AF) with circumferential pulmonary vein (PV) linear ablation guided by 3 dimensional mapping system and single circular mapping catheter.

METHODSFrom April 2004 to January 2005, PV isolation with circumferential PV linear ablation guided by CARTO system (in 76 patients) or EnSite-NavX system (in 24 patients) was performed in 100 consecutive patients with significantly symptomatic, drug refractory AF. The procedural end-point was complete electrical isolation of bilateral PV.

RESULTSUp to 200 linear circles were produced around each ipsilateral PVs in all 100 cases, and 95.0% (190/200) of PV isolation rate was achieved with a mean procedure time of 150-365 (240 +/- 65) min and a mean fluoroscopy time of 23-61 (37 +/- 12) min, respectively. Eight cases with recurrent AF (8.0%) underwent second session. Cumulative atrial tachyarrhythmias-free rate was 85.0% (85/100) during a mean follow-up of 5.5-12 (10.2 +/- 5.7) months. Atrial tachyarrhythmias-free rate was 66.0% (66/100), 82.0% (82/100), 87.0% (87/100), 85.0% (85/100), 85.0% (85/100), and 88.6% (70/79) during the follow up at 1 month, 2 months, 3 months, 4 months, 5 months and 6 months, respectively. There were 2 complications (1 tamponade and 1 PV stenosis), which were rehabilitated after conservative treatment.

CONCLUSIONPV isolation with circumferential PV linear ablation guided by 3 dimensional mapping system is safe and effective for treating AF.

Adolescent ; Adult ; Aged ; Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Feasibility Studies ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Pulmonary Veins ; surgery ; Treatment Outcome ; Young Adult

BACKGROUND: Inducing factors are currently used as a main method for the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocytes. OBJECTIVE: To investigate the collaborative stimulation of transforming growth factor beta1 (TGF-β1) and insulin-like growth factor 1 (IGF-1) to induce the directed differentiation of BMSCs to chondrocytes, and to explore the best inductive effect. METHODS: Rat BMSCs were isolated, cultured and purified using adherent culture. Then, different inducing factors were added in the induction medium: TGF-β1+IGF-1 group, TGF-β1 group, IGF-1 group, and control group without growth factors. Immunofluorescence was carried out at 21 days of induction. The expression of collagen type Ⅱ was evaluated by immuncytochemical staining at 7, 14 and 21 days of induction. RESULTS AND CONCLUSION: (1) Immunofluorescence detection of the TGF-β1+IGF-1 and TGF-β1 groups showed highly expressed collagen type Ⅱ (brown red-stained cytoplasm), while negatively expressed collagen type Ⅱ in the other two groups. (2) Findings from the immuncytochemical staining showed that the expression of collagen type Ⅱ was stronger in the TGF-β1+IGF-1 group than the TGF-β1 group (P < 0.01), and the expression was gradually enhanced with time. Meanwhile, there was also no expression of collagen type Ⅱ in the IGF-1 and control groups. To conclude, the combination of TGF-β1 and IGF-1 can achieve the better inductive effect on the chondrogenic differentiation of BMSCs in vitro.