Min Tang

Peking Union Medical College Hospital, Peping, Beijing, China

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Publications (12)27.28 Total impact

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    ABSTRACT: IntroductionElectrical reconnection of the pulmonary veins (PVs) plays a key role in the recurrence of atrial fibrillation (AF) after ablative treatment. This randomized controlled study tested the hypothesis that prolonged ablations, on areas that may be critical for left atrial (LA)-PV conduction, can significantly reduce the rate of acute PV reconnection and AF recurrence. Methods Patients with paroxysmal AF were randomly assigned to either a control or an add-on group. Ostial PV isolation (PVI) was performed by point-to-point RF ablation (irrigated tip, 30 Watts, 30 seconds). An ostial segment was assumed to be critical for LA-PV connection if any of the following reactions occurred during RF application: (1) sudden delay of LA-PV conduction, (2) change of activation sequence, and (3) PVI. In this case, RF application was prolonged from 30 seconds to 90 seconds in the add-on group only. ResultsA total of 131 patients (58 ± 11 years, 47 female) were assigned to a control (n = 64) and an add-on (n = 67) group. Ablation time was longer in the add-on (48 ± 16 minutes vs 37 ± 15 minutes, P = 0.03). Acute PV reconnection was observed in 20 of 64 controls and in eight of 66 add-on patients (31% vs 12%, P < 0.001). During a follow-up of 26 months, AF recurred in 33 of 64 controls and in 16 of 66 add-on patients (52% vs 24%, P = 0.001) after a single ablation procedure. Conclusions Prolonged radiofrequency application on critical segments of LA-PV connection is a safe and effective ablative strategy that significantly reduces acute PV reconnection and AF recurrence rates after a single ablation procedure for paroxysmal AF.
    Pacing and Clinical Electrophysiology 11/2013; · 1.75 Impact Factor
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    ABSTRACT: A novel circular pulmonary vein ablation catheter (PVAC) has been introduced for pulmonary vein isolation (PVI). Accurate delineation of left atrium-pulmonary vein (LA-PV) anatomy is important for this technique. The aim of this study was to test whether the 3-dimensional rotational angiography (3D RTA) of the left atrium can facilitate PVI using PVAC technique. Twenty patients with paroxysmal atrial fibrillation (AF) were enrolled in this study. The 3D RTA was reconstructed and registered with live fluoroscopy in all the patients. AF ablation was performed with a PVAC catheter in the navigation of registered 3D RTA. The 3DRTA image was successfully reconstructed and registered with live fluoroscopy in all patients (100%). The LA-PV anatomy was delineated clearly in all patients. Navigation of the PVAC inside the registered 3D RTA, ensured accurate placement within the atrium to perform ablation, and the PVAC was correctly placed inside the PV ostium to verify the PVI. All the PVs were isolated. Total procedural time was (87.5 ± 12.1) minutes, and fluoroscopy time was (20.1 ± 6.3) minutes. Follow-up after (7.1 ± 1.5) months showed freedom from AF in 70% (14/20) patients. No PV stenosis was observed. Intraprocedure reconstructed and registered 3D RTA can clearly delineate the LA-PV anatomy in real-time. The results demonstrate the feasibility and reliability of combining use of 3DRA and PVAC in AF ablation procedures.
    Chinese medical journal 01/2012; 125(1):144-8. · 0.90 Impact Factor
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    ABSTRACT: Atrial fibrillation (AF) is associated with electroanatomical remodelling of the left atrium (LA), especially with LA dilatation. However, little is known about the changes of the three-dimensional structure of the LA, regarding the type of atrial fibrillation and their prognostic value after an ablative treatment. One hundred fifteen patients (72 males, 59 ± 11 years) with an indication for AF ablation were prospectively included. Preoperatively, all patients underwent cardiac computed tomography (CCT). A reconstruction of the LA and the pulmonary veins (PV) was made from CCT data using specialized software (EP PreNavigator, Philips, The Netherlands). Left atrial volume (LAV) after exclusion of the atrial appendage (LAA) and the PV was determined. The LA was then arbitrarily divided by a cutting plane, between the anterior segment of the PV ostia and the atrial appendage and parallel to the posterior wall, to anterior-(LA-Ant.) and posterior-LA (LA-Post.). The ratio LA-Ant./LAV was defined as asymmetry index (ASI). The cardiac CT data, of 25 patients (11 women, 47 ± 11 years) without organic heart disease, were similarly studied for the same parameters, as a control group. Patients with paroxysmal AF (n = 63) had significantly higher LAV (131 ± 31 vs. 95 ± 18 ml, p < 0.001) and higher ASI (61 ± 6 % vs. 57 ± 4, p = 0.002) than the control group. Patients with persistent AF (n = 34) in comparison with paroxysmal AF showed significantly larger volumes (154 ± 44 vs. 131 ± 31 ml, p = 0.007) but no difference in the ASI (60 ± 8% vs. 61 ± 6%, p = 0.63). Finally, patients with long-term persistent AF (n = 18) showed a bigger asymmetry index than the patients with persistent AF (64 ± 5% vs. 60 ± 8%, p = 0.06) but no significant difference in volumes (161 ± 21 vs. 154 ± 44 ml, p = 0.49). LAA and partial LA volumes had a dilatation pattern similar to LAV. During a follow-up of over 25 ± 7 months, AF recurred in 31 (27%) patients. Multivariate analysis showed that ASI and LAV were the only two significant predictors of AF recurrence after ablative treatment. Independent of LAV, an ASI over 60% predicted AF recurrence with 74% sensitivity and 73% specificity. Characteristic differences of both left atrial volume and geometry exist between the different forms of atrial fibrillation (paroxysmal, persistent and long-term persistent). The asymmetry index is a simple parameter derived by cardiac CT data that reflects these changes of LA geometry and predicts the outcome after the pulmonary vein isolation.
    Journal of Interventional Cardiac Electrophysiology 06/2011; 32(2):87-94. · 1.39 Impact Factor
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    ABSTRACT: Atrial fibrillation (AF) ablation is facilitated by anatomical visualization of the left atrium (LA) and the pulmonary veins (PVs). The purpose of this study was to compare accuracy, radiation exposure, and costs between three-dimensional atriography (3D-ATG) and cardiac computed tomography (CCT). Seventy patients with an indication for AF ablation were included. Contrast-enhanced CCT was performed preoperatively for all patients. In addition, intraoperative 3D-ATG was performed with contrast medium injection either indirectly into the pulmonary arteries during a breath-hold (Ind.-RTA, n = 25) or directly into the LA, during adenosine-induced asystole (Ad.-RTA, n = 23), or rapid ventricular pacing (VP-RTA, n = 22). We evaluated vertical ostial PV diameters and LA volume, time needed to perform, radiation exposure, and procedural cost for each imaging method. The correlation coefficient between 3D-ATG and CCT for the ostial PV diameters was r = 0.83 for Ind.-RTA, 0.91 for Ad.-RTA, and 0.88 for the VP-RTA method (P > 0.05). The volume correlations were r = 0.87 for Ind.-RTA, 0.82 for Ad.-RTA, and 0.8 for VP-RTA (P > 0.05). Time to perform was 13 ± 5 minutes for ATG and 46 ± 9 minutes for CCT (P < 0.05). Effective radiation dose was 2.2 ± 0.2 mSv for ATG and 20.4 ± 7.4 mSv for CCT (P < 0.05). The procedural cost was estimated at 91-95 € for ATG and at 126-151 € for CCT. 3D-ATG is an intraprocedural imaging modality that provides anatomical accuracy comparable to that of CCT with significantly lower radiation dose, in less time and at less financial expense (PACE 2011; 34:315-322).
    Pacing and Clinical Electrophysiology 11/2010; 34(3):315-22. · 1.75 Impact Factor
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    ABSTRACT: The study was designed to evaluate the feasibility and efficacy of a simplified cryoballoon technique in which a microcircular catheter was introduced into the central lumen of a cryoballoon catheter for the purpose of recording pulmonary vein (PV) potentials during ablation procedures and without interchanging catheters. A total of 23 consecutive patients with paroxysmal atrial fibrillation (AF) were enrolled. A single transseptal puncture was made and a cryoballoon catheter was inserted into the left atrium. A 6-pole mapping catheter with a 0.035-inch shaft diameter was introduced into the PV through the central lumen of the cryoballoon catheter. In addition to the function as a recording device, the mapping catheter was also used as a "guide-wire" during the procedure. A total of 84 PVs (84/92, 91.3%) were completely isolated using this novel cryoballoon technique. In 43 of the 84 veins (51.2%), isolation was observed in real time during the cryoablation; in the remaining 41 veins (48.8%), isolation was confirmed immediately post ablation attempt with the mapping catheter. Procedure time was 152.7 +/- 54.9 minutes, and fluoroscopy time was 33.2 +/- 17.3 minutes. At follow-up (7.4 months, range 2-18 months), 17 (73.9%) patients were free from AF. There was 1 occurrence of phrenic nerve palsy during ablation of a right superior PV, which fully resolved after 1 month. The use of a cryoballoon catheter equipped with a 6-pole micromapping catheter inserted through its central lumen for the purpose of mapping and ablation during PV isolation procedures is both feasible and effective.
    Journal of Cardiovascular Electrophysiology 12/2009; 21(6):626-31. · 3.48 Impact Factor
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    ABSTRACT: The accurate assessment of pulmonary vein (PV) anatomy is important in planning radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). The aim of the present study was to perform a head-to-head comparison of magnetic resonance imaging (MRI) and multislice computed tomography (CT) for the evaluation of PV morphology before RFCA of AF. Contrast-enhanced MRI (on a 1.5-T system) and multislice CT (on a dual-source system) were performed for the evaluation of the PVs in 44 consecutive patients (31 men, mean age 56 +/- 10 years) admitted for RFCA of drug-refractory AF. Data on PV anatomy, ostial branching pattern, and ostial dimensions were compared between MRI and multislice CT. Variant PV anatomy was observed in 21 patients (48%) with the 2 imaging approaches. The incidence of PV ostial branching, as assessed with MRI and multislice CT, was higher on the right and more common in the inferior than superior vein. Agreement between the 2 imaging modalities for the evaluation of variant PV anatomy (kappa = 0.87, 95% confidence interval 0.77 to 0.97) and ostial branching pattern (kappa = 0.84, 95% confidence interval 0.75 to 0.93) was nearly perfect. Assessment of PV ostial cross-sectional area as well as maximal and minimal ostial diameters resulted in strong agreement and correlation (r(2) = 0.75 to 0.99, p <0.001 for all) between the 2 imaging approaches. In conclusion, MRI and multislice CT of the PVs appear to provide similar and detailed anatomic and quantitative information before RFCA of AF.
    The American journal of cardiology 12/2009; 104(11):1540-6. · 3.58 Impact Factor
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    ABSTRACT: Electrical isolation of the pulmonary veins (PVs) is the cornerstone of the ablative treatment of atrial fibrillation. Selective angiography of the PVs in standard fluoroscopic projections is often used for intraprocedural identification of PVs and their ostia. Variable spatial orientation and significant variability of PV anatomy are important limitations of this imaging approach. Sixty patients undergoing a PV isolation procedure received intraprocedural rotational angiography and three-dimensional reconstruction of the left atrium (LA) and PVs. For each patient, 33 angiographic projections were independently evaluated [right anterior oblique (RAO) 80 degrees to left anterior oblique (LAO) 80 degrees, in steps of 5 degrees] by two physicians in order to identify the optimal projections of the PV ostia according to the following definition: Sagittal plane: (i) clear identification of both superior and inferior segments of the LA-PV junction and (ii) no overlapping between LA (and/or left atrial appendage) and PV ostium. Frontal plane: (i) clear identification of all four quadrants of the PV ostium and (ii) fluoroscopic angles at which the maximal horizontal ostial diameter is visualized. A successful reconstruction of the LA and all PVs was obtained in 58 (97%) patients. An optimal ostial projection in a sagittal plane was identified for all four PVs. The optimal ostial projection was RAO 5 degrees for the right superior PVs in 57 out of 58 patients (98%), RAO 55 degrees for the right inferior PVs in 54 out of 58 patients (93%), LAO 45 degrees for the left superior PVs in 46 out of 58 patients (80%), and LAO 60 degrees for the left inferior PVs in 48 out of 58 patients (83%). An optimal ostial projection in a frontal plane was identified only for the inferior PVs. The optimal ostial projection was LAO 40 degrees for the right inferior PVs in 55 out of 58 patients (95%) and RAO 45 degrees for the left inferior PVs in 51 out of 58 patients (88%). If selective angiography is to be used to delineate anatomy and location of the PV ostia to guide PV isolation, different fluoroscopic projections are required for different PVs. The preselected RAO and LAO projections proposed in our study result in optimal angiographic projections of all PV ostia in at least one plane in the majority of patients.
    Europace 11/2009; 12(1):37-44. · 2.77 Impact Factor
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    ABSTRACT: Three-dimensional (3D) image of left atrium (LA) can greatly facilitate ablation of atrial fibrillation (AF). Reconstructing method using computed tomography (CT) has certain limitations. The 3D image of LA can be intraprocedurally reconstructed by a rotational angiography technique. Forty-six patients undergoing AF ablation were included in this study. Preprocedural CT imaging and intraprocedural reconstructing 3D rotational angiogram (3DRA) of LA were performed in all the patients. Rapid ventricular pacing (RVP, 300 ms) was used to inhibit the drainage of atrium. During RVP, contrast medium was injected into the LA, and rotational angiography was performed. The 3DRA was reconstructed and was registered with the live fluoroscopy. The 3DRA was evaluated in comparison to the CT image. In the navigation of the registered 3DRA, the ablation of AF was performed. Forty-four 3DRAs (95.7%) were successfully reconstructed and registered with the live fluoroscopy. The LA anatomy was delineated in the 3DRA in comparison to a CT image. AF ablation was successfully performed in the 44 patients in the navigation of the registered 3DRA. There were good correlations in the PV ostial diameter and the LA volume as assessed by 3DRA in comparison to a CT image (r>=0.87). The radiation exposure in rotational angiography was substantially less than that in CT scanning (2.7+/-0.9 mSv vs. 24.9+/-3.1 mSv, P<0.001). It is feasible to reconstruct and register the 3DRA with live fluoroscopy using the RVP method during the ablation of AF.
    Pacing and Clinical Electrophysiology 08/2009; 32(11):1407-16. · 1.75 Impact Factor
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    ABSTRACT: Conventional pulmonary vein (PV) angiography cannot precisely delineate the left atrium (LA)-PV anatomy, which is essential for the ablation of atrial fibrillation (AF). The aim of the study was to test the feasibility of a novel method of rotational angiography for the AF ablation. Forty-one patients were enrolled in this study. CT scanning was performed in all patients before the procedure. Rotational angiography (rotating from right anterior oblique 55 degrees to left anterior oblique 55 degrees ) was performed before AF ablation. Rapid ventricular pacing (RVP, 300 ms) was carried out to reduce cardiac output while contrast medium was injected into the LA via a pigtail catheter. RVP was successfully performed in 36 (87.8%) patients. The ostia of all PVs and the LA appendage were visible in all these 36 cases. There was a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP as compared to CT imaging (r (2) > 0.85). Rotational angiography by RVP is able to delineate the LA-PV anatomy. There is a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP and CT imaging. Rotational angiography by RVP is feasible during AF ablation.
    Journal of Interventional Cardiac Electrophysiology 05/2009; 26(2):101-7. · 1.39 Impact Factor
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    ABSTRACT: Pulmonary vein (PV) isolation is a technically challenging intervention. For this reason, integration of three-dimensional imaging with computed tomography (CT) or magnetic resonance imaging (MRI) in order to enhance effectiveness and safety has been widely adopted. A novel imaging approach--intraprocedural rotational angiography and reconstruction of the left atrium and PVs--is feasible and provides high anatomic accuracy. The purpose of this study was to prove the feasibility, safety, and efficacy of this imaging approach as a single navigation tool for PV isolation. Forty-four patients (25 men and 19 women; age 57 +/- 11 years) with atrial fibrillation (AF) who presented for PV isolation were studied. Rotational angiography during adenosine-induced ventricular asystole was performed under sedation with propofol. The left atrium and PVs were reconstructed by three-dimensional atriography using specialized software (EP navigator prototype, Philips Medical Systems). Three-dimensional atriography was used as a single navigation tool for guiding PV isolation. Of 176 PVs, 174 (99%) were isolated. Total procedural and fluoroscopy times were 192 +/- 46 minutes and 44 +/- 12 minutes, respectively. During follow-up of 6 +/- 3 months, 31 (70%) patients were free of symptoms and had no evidence of AF without any antiarrhythmic medication. MRI examination of 41 patients at 3-month follow-up excluded PV stenosis. No major complications occurred. Three-dimensional atriography is a novel intraprocedural three-dimensional imaging technique that is based on rotational angiography. It can be safely and effectively used as a single navigation tool for performing PV isolation.
    Heart rhythm: the official journal of the Heart Rhythm Society 03/2009; 6(6):733-41. · 4.56 Impact Factor
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    ABSTRACT: Atrial fibrillation ablation is a complex procedure that requires detailed anatomic information about left atrium (LA) and pulmonary veins (PVs). The goal of this study was to test rotational angiography of the LA during adenosine-induced asystole as an imaging tool in patients undergoing atrial fibrillation ablation. Seventy patients with paroxysmal or persistent atrial fibrillation undergoing PV isolation were included. After transseptal puncture, adenosine (30 mg) was given intravenously, and during atrioventricular block, contrast medium was directly injected in the LA; a rotational angiography was performed (right anterior oblique 55 degrees to left anterior oblique 55 degrees). Rotational angiography images were assessed qualitatively in all patients and quantitatively in 45 patients in comparison with computed tomography (CT) images. The majority of rotational angiography imaging data (94%) were deemed at least 'useful' in delineating the LA-PV anatomy. The so-called 'ridge' between left superior PV and left atrial appendage was delineated in 90% of the patients. All accessory PVs were independently identified by rotational angiography and CT. A blinded quantitative comparison of PV ostial diameters showed an excellent correlation between rotational angiography and CT measurements (r > 0.90 for all PVs). No serious adverse effects occurred in association with adenosine. Intra-procedural contrast-enhanced rotational angiography of the LA-PV during adenosine-induced asystole is feasible and provides anatomical information of high diagnostic value for atrial fibrillation ablation.
    Europace 01/2009; 11(1):35-41. · 2.77 Impact Factor
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    Hellenic journal of cardiology: HJC = Hellēnikē kardiologikē epitheōrēsē 50(4):324-9. · 1.23 Impact Factor

Publication Stats

79 Citations
27.28 Total Impact Points

Institutions

  • 2009–2013
    • Peking Union Medical College Hospital
      Peping, Beijing, China
  • 2011
    • Deutsches Herzzentrum Berlin
      • Cardiothoracic and Vascular Surgery
      Berlín, Berlin, Germany
  • 2009–2010
    • Renmin University of China
      Peping, Beijing, China