Initial experience with ablation of the innervation surrounding sinus and atrioventricular nodes to treat paroxysmal bradyarrhythmia.

BACKGROUND: The symptomatic bradyarrhythmia is Class I indication for pacing therapy which is not a radical cure. The present study aimed to assess the feasibility and to present the initial results of the restricted ablation of the parasympathetic innervation surrounding sinus and atrioventricular (AV) nodes for treating patients with bradyarrhythmia. METHODS: A total of 13 patients with cardiogenic syncope were included from May 2008 to June 2015. Under the guidance of fluoroscopy and /or three-dimensional geometry by 64-slice spiral computed tomography, atrial activation sequence in sinus rhythm was mapped. Chamber geometry was reconstructed manually or automatically using the Niobe II magnetic navigation system integrated with the CARTO-remote magnetic technology (RMT) system. Cardioneuroablation was targeted at the high-amplitude fractionated electrograms surrounding the regions of His bundle and the site with the earliest activation in sinus rhythm. Areas surrounding the sinus node, AV node, and the phrenic nerve were avoided. RESULTS: Thirteen patients completed the studies. Ablation was successfully performed in 12 patients and failed in one. The high-frequency potential was recorded in atrial electrograms surrounding the sinus or AV nodes in all the patients and disappeared in 15 s after radiofrequency applications. The vagal reaction was observed before the improvement of the sinus and AV node function. No complications occurred during the procedures. Patients were followed up for a mean of 13.0 ±â€Š5.9 months. During the follow up ten patients remained free of symptoms, and two patients had a permanent cardiac pacemaker implanted due to spontaneous recurrence of syncope. The heart rate of post-ablation was higher than pre-ablation (69.0 ±â€Š11.0 vs. 49.0 ±â€Š10.0 beats/min, t = 4.56, P = 0.008). The sinus node recovery time, Wenckebach block point, and atrium-His bundle interval were significantly shorter after ablation (1386.0 ±â€Š165.0 vs. 921.0 ±â€Š64.0 ms, t = 7.45, P = 0.002; 590.0 ±â€Š96.0 vs. 464.0 ±â€Š39.0 ms, t = 2.38, P = 0.023; 106.0 ±â€Š5.0 vs. 90.0 ±â€Š12.0 ms, t = 9.80, P = 0.013 before and after ablation procedure, respectively). CONCLUSIONS: Ablation of sinoatrial and AV nodal peripheral fibrillar myocardium electrical activity might provide a new treatment to ameliorate paroxysmal sinus node dysfunction, high degree AV block, and vagal-mediated syncope.

High volume practice proved the safety of off-pump coronary artery bypass surgery in left main coronary artery lesions: a two-year single center experience.

BACKGROUND: Left main coronary artery (LMCA) stenosis has been recognized as a risk factor for early death among patients undergoing coronary artery bypass grafting (CABG). This study aimed to assess if LMCA lesions pose an additional risk of early or mid-term mortality and/or a major adverse cardiac and cerebrovascular event (MACCE) after off-pump coronary artery bypass grafting (OPCABG), compared with non-left main coronary artery stenosis (non-mainstem disease). METHODS: From January 1, 2009 to December 31, 2010, 4869 patients had a primary isolated OPCABG procedure at Beijing Anzhen Hospital. According to the pathology of LMCA lesions, they were retrospectively classified as a non-mainstem disease group (n = 3933) or a LMCA group (n = 936). Propensity scores were used to match the two groups, patients from the non-mainstem disease group (n = 831) were also randomly selected to match patients from the LMCA group (n = 831). Freedom from MACCE in the two groups was calculated using the Kaplan-Meier method. RESULTS: The difference in the mortality and the rate of MACCE during the first 30 days between the non-mainstem disease group and the LMCA group did not reach statistical significance (P = 0.429, P = 0.127 respectively). With a mean follow-up of (12.8 ± 7.5) months and a cumulative follow-up of 1769.6 patient-years, the difference in the freedom from MACCEs between the two groups, calculated through Kaplan-Meier method, did not reach statistical significance (P = 0.831). CONCLUSION: Analysis of a high volume of OPCABG procedures proved that LMCA lesions do not pose additional early and mid-term risk to OPCABG. Therefore, a LMCA lesion is as safe as non-mainstem disease lesion during the OPCABG procedure.

[Asymptomatic recurrence of atrial tachy-arrhythmia after circumferential pulmonary vein isolation in patients with atrial fibrillation].

OBJECTIVE: To investigate the incidence, type, and predictors of asymptomatic relapse of atrial tachy-arrhythmia (ATa) after circumferential pulmonary vein isolation (CPVI) in patients with atrial fibrillation (AF). METHODS: Forty-eight consecutive patients with AF underwent CPVI and were followed up. Forty-eight hours Holter recording was performed 1, 3, and 6 months respectively after the initial CPVI procedure. Predictors of asymptomatic ATa relapse were determined by Logistic regression analysis for eight variables as follows: age, gender, AF type, existence of organic heart disease, diameter of left atria, left ventricular ejection fraction, procedure time, and heart rate variability after the procedure. RESULTS: Complete Holter data were acquired in 42 patients, 26 males and 16 females, aged: 58 +/- 14, including 25 patients with paroxysmal AF and 17 with non-paroxysmal AF. The standard deviations of R-R interval (SDNN) of the non-paroxysmal AF group was 92 ms +/- 19 ms, significantly longer than that of the paroxysmal AF group (78 ms +/- 15 ms, P = 0.011). The incidence of asymptomatic ATa recurrence rates 1, 3 and 6 months after CPVI were 8%, 12%, and 8% respectively in paroxysmal AF group and 23.5%, 29.4%, and 35.3% respectively in the non-paroxysmal AF group. The incidence of asymptomatic ATa recurrence 6 months after CPVI in the non-paroxysmal AF group was significant higher than that in the paroxysmal AF group (P < 0.05). AF was the dominant arrhythmia among the asymptomatic recurrence ATa, while atrial tachycardia constituted the major arrhythmia of the symptomatic recurrent ATa. CONCLUSION: (1) Asymptomatic ATa relapse is common among the patients undergoing CPVI. (2) The dominant type of asymptomatic recurrent arrhythmia is AF. (3) The independent predictors for asymptomatic ATa recurrence include non-paroxysmal AF, left atrial enlargement, and increase of SDNN.

Catheter ablation of atrial fibrillation in patients with hyperthyroidism.

AIMS: To study the clinical efficacy of catheter ablation for treating patients with hyperthyroidism-related atrial fibrillation (AF). MATERIALS AND METHODS: The study involved 16 patients (12 males; age, 59.8 +/- 11.3 years) with hyperthyroidism-related AF, who had all been euthyroid for more than 3 months but still suffered from highly symptomatic and antiarrhythmia drug (AAD)-refractory AF. Circumferential pulmonary vein ablation (CPVA) guided by a 3-D mapping system was carried out to encircle the ipsilateral pulmonary veins (PVs) with a procedural endpoint of continuity of the circular lesions and PV isolation. Success was defined as the absence of any atrial tachyarrhythmia (ATa) off AADs beyond the first 3 months after the procedure. RESULTS: CPVA was safely carried out in each of the 16 patients without any complications. PV isolation was achieved in all the treated PVs. After a mean follow-up of 15.8 +/- 11.8 (range, 6-55) months, 9 patients (56%) were free of ATa without any AADs beyond the first 3 months. AF relapsed in the remaining 7 patients, among whom 4 responded to AAD therapy and 3 were totally unresponsive. CONCLUSION: For patients suffering hyperthyroidism-related AF, CPVA guided by a 3-D mapping system could represent one of the therapeutic options.

Can pulmonary vein antrum be defined by electrophysiological mapping?

Atrial fibrillation (AF) is the most common sustained arrhythmia, and treatments with anti-arrhythmia drugs (AADs) have been frustrating. Limitations of AADs prompted the development of percutaneous catheter ablation. In contrast to AADs, percutaneous catheter ablation offers the possibility of a lasting cure. The successful cure of AF by percutaneous catheter ablation comes from a widespread recognize that pulmonary vein antrum (PVA) plays an important role in the genesis and maintenance of AF, and circular ablation along the PVA can eliminate majority of AF. PVA is comprised of pulmonary vein-left atrium junctions. However, during ablation procedure, definition of PVA solely depends on angiography, and it is largely experience-dependent and there is a great deal of variation involved. Our study in patients with AF found that a unique potential with double deflections could be documented along PVA, but it cannot be recorded at PV side or LA side. Thus, we propose that documentation of PVA potentials can be used as a landmark to define PVA. Unlike angiography, documentation of PVA potentials can be objectively carried out by different operators, and the variations due to experience can be avoided.

Pulmonary vein tachycardia after pulmonary vein isolation in patients with atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation has been developed to treat patients with atrial fibrillation (AF), and the electrophysiological endpoint of PV isolation is the disappearance or dissociation of pulmonary vein potentials (PVPs). Pulmonary vein tachycardia (PVT) is the dissociated PV rhythm with a rapid rate. However, the characteristics and significance of PVT after pulmonary vein isolation in patients with AF remains unclear. METHODS: From June 2003 to June 2005, a total of 285 consecutive patients with drug refractory AF were included in this study, and they underwent segmental pulmonary vein ablation (SPVA) or circumferential pulmonary vein ablation (CPVA). PV isolation was the initial endpoint for both approaches with documenting disappearance or dissociation of PVPs. PVT was characterized as dissociated activities within PVs with a circle length (CL) of < 300 ms, and was classified into organized PVT or disorganized PVT according to the variance of CL. Systematic follow-up was conducted after initial procedures. Continuous variables were analyzed by Student's t test and categorical variables were analyzed by chi-square test. RESULTS: Three hundred and fifteen PVs were ablated in 85 patients underwent SPVA approach, 400 circular lesions surrounding ipsilateral PVs (including 790 PVs) were produced in the rest of 200 patients received CPVA approach. Electrical isolation was achieved in all of these PVs. Of these, PVPs were abolished in 89.8% (992/1105) of the ablated PVs, dissociated PV rhythms were documented in the rest 10.2 % (113/1105) of the treated PVs. Among the 113 dissociated PV rhythms, 28 met the criteria of PVT with mean CL of (155 +/- 43) ms (2 PVTs in 2 patients received SPVA, 26 PVTs in 18 patients underwent CPVA). PVT was more frequently documented in patients underwent CPVA approach [9.0% (18/200) vs 2.3% (2/85), P = 0.04]. During the 6-month follow-up, it was indicated that no significant difference existed in AF free rate between patients with PVT and those without PVT (P = 0.75). CONCLUSIONS: PVT dissociated from LA activations can be documented after PV isolation, especially in patients underwent CPVA approach. However, PVT does not affect the follow-up results.

Safety and efficacy of catheter ablation of atrial fibrillation in patients with diabetes mellitus--single center experience.

BACKGROUND AND OBJECTIVE: Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with diabetes mellitus (DM). We investigated the safety and efficacy of catheter ablation of AF in patients with DM. MATERIALS AND METHODS: Thirty one patients with DM from a group of 263 consecutive patients undergoing a first-time catheter ablation of AF procedure were enrolled in a prospective study. The ablation protocol (guided by CARTO system) consisted in two continuous circular lesions around ipsilateral pulmonary veins. RESULTS: The following clinical characteristics differed between DM and no-DM patients: age (62.0 +/- 10.8 vs. 56.1 +/- 10.6 years, P = 0.004), longer AF history (9.6 +/- 9.3 vs. 6.7 +/- 6.3 years, P = 0.024), significantly larger left atrium size (41.1 +/- 7.8 vs. 38.3 +/- 5.8 mm, P = 0.021), hypertension (58.1 vs. 35.8%, P = 0.018) and structural heart disease (67.7 vs. 43.5%, P = 0.011). Despite a similar AF recurrence rate in DM and no-DM patients (32.3 vs. 22.4%, P = 0.240), the ablation procedure was complicated in 28 patients (11 hematomas, three cardiac tamponades and three strokes) and the incidence of complications was significantly higher in DM than in no-DM patients (29.0 vs. 8.2%, respectively, P = 0.002). Multivariate analysis showed that DM was an independent risk factor for complications occurrence (odd ratio 5.936, 95% confidence interval 2.059 to 17.112, P = 0.001). CONCLUSIONS: First catheter ablation of AF procedure in DM patients was equally efficacious than in no-DM patients. However, DM patients had a higher incidence of complications, mostly thrombotic or hemorrhagic.