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Chinese medical journal 10/2012; 125(19):3587-8. · 0.86 Impact Factor
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ABSTRACT: Verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) combined with a left accessory pathway (AP) is a relatively rare condition. This study examines the characteristics of patients with this condition and the effect of radiofrequency catheter ablation (RFCA).
Catheter ablation was performed on 140 ILVT patients at a single centre from January 2004 to December 2009. A concealed left AP was found in seven patients (5%), all of whom were male, with an average age of 21 ± 9 years. Sustained ILVT and orthodromic atrioventricular reentrant tachycardia (AVRT) were induced in all seven patients. Retrograde activation through a bystander AP occurred concomitantly with ILVT, with an average tachycardia length of 346 ± 29 ms (range 310-400 ms). The location of the APs in four patients was left posterior, two of which showed a slow and decremental property, while in three it was left lateral. Ablation via a retrograde transaortic approach was performed in the seven patients. The left AP was ablated first in six patients, but ILVT was no longer induced in one and became non-sustained in another. In the seventh patient, ILVT was ablated first and this proved successful.
Among patients with IVLT, 5% had a concomitant left AP, most of who were young men. The location of the left AP was mainly posterior and lateral, with 30% showing a slow and decremental property. Idiopathic left ventricular tachycardia and AP should be ablated simultaneously.
Europace 10/2011; 14(5):703-8. · 1.98 Impact Factor
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ABSTRACT: The characteristics and response to ablation therapy of focal atrial tachycardia (AT) originating from the distal portion of left atrial appendage (LAAd) are still not quite clear up to now. The goal of this study is to characterize electrocardiographic and electrophysiological features and radiofrequency ablation (RFA) outcomes in patients with focal AT originating from the LAAd.
Fourteen patients (2.1%) (mean age, 25 ± 10 years; nine women; mean symptom duration, 5 ± 5 years) undergoing RFA of focal AT originating from the LAAd were included out of 668 RFA patients. Activation mapping was performed. P waves were classified as negative, positive, isoelectric, or biphasic. Tachycardia that was incessant in all, demonstrated a characteristic P-wave morphology and endocardial activation pattern: P wave was negative in leads I and aVL, highly positive in the inferior leads, and broad and positive in lead V₁. Radiofrequency ablation was acutely successful in 13 of 14 patients. The endocardial activation time of the successful RFA sites was 47.1 ± 4.3 ms before the onset of P wave. There were no complications in any of the 14 patients and long-term success was achieved in 13 of 13 successful RFA patients during follow-up (5 ± 2 years).
The LAAd is an uncommon site of origin for focal AT (2.1% incidence). In this case series, focal ATs originating from the LAAd had typical electrophysiological and electrocardiographic characteristics. Focal ablation yielded high acute success rate with low rate of recurrence during follow-up.
Europace 09/2011; 14(2):254-60. · 1.98 Impact Factor
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ABSTRACT: Selective ipsilateral pulmonary vein isolation (SIPVI) has shown comparable efficacy in focal triggered atrial fibrillation (AF) versus isolation of all pulmonary veins (PVs), yet the sufficiency for such an ablation strategy to all patients is unclear. This study sought to identify a subgroup of patients for SIPVI and a subgroup of patients for bilateral PV isolation (BiPVI) with long-term success by comparing the clinical efficacy of SIPVI and BiPVI on PV-triggered AF.
One hundred and forty-two patients (106 males; mean age 51 ± 13 years) with focal PV triggered paroxysmal AF (PAF) were studied. Seventy patients underwent SIPVI and 72 patients underwent BiPVI. After the first ablation, 44 patients (44/70) in the SIPVI group and 54 patients (54/72) in the BiPVI group were free of AF without antiarrhythmic drugs, after a follow-up period of 36 ± 12 months (log-rank test P = 0.1594). In patients younger than 50 years of age with a left atrium (LA) diameter <40 mm, SIPVI had a high success rate (15/18, 83%) of freedom from AF. However, for patients aged ≥50 years with an LA diameter ≥40 mm, 10 of the 12 patients in the SIPVI group and only 5 of the 15 patients in the BiPVI group had a recurrence of AF (log-rank test P = 0.0173).
For focally triggered PAF, in patients aged <50 years with an LA diameter <40 mm, SIPVI of triggering PV had a high success rate of freedom from AF. However, in patients aged ≥50 years with an LA diameter ≥40 mm, BiPVI achieved a higher success rate.
Journal of Cardiovascular Electrophysiology 09/2011; 23(2):130-6. · 3.06 Impact Factor
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ABSTRACT: Patients with persistent or permanent atrial fibrillation (AF) often need direct current cardioversion after radiofrequency ablation. The aim of this study was to investigate the effectiveness and safety of ibutilide for cardioversion of persistent or permanent atrial fibrillation after radiofrequency ablation and the factors related to conversion.
Patients with persistent or permanent atrial fibrillation were treated with combined ablation strategy including circumferential pulmonary vein isolation, linear ablation and CAFÉ potential ablation. If AF was not terminated after ablation, ibutilide was used for cardioversion (1 mg, intravenous injection in 10 minutes). These patients were divided into a conversion group and a non-conversion group according to whether AF was converted to sinus rhythm within 30 minutes after administration. ECG monitoring was performed during the injection of ibutilide. Atrial waves recorded by coronary sinus electrodes were measured for calculating average wavelength of AF waves in six seconds. The QT interval was measured immediately after conversion and 2 hours after injection of ibutilide.
Forty patients whose AF was not converted to sinus rhythm after radiofrequency ablation were given an intravenous injection of ibutilide. Of the 40 patients, 29 cases were converted to sinus rhythm, with a conversion rate of 72.5%. The average conversion time was (13.2 ± 5.5) minutes. Compared with the conversion group, patients in the non-conversion group had a longer history of AF (9.4 ± 5.3) years vs. (4.3 ± 2.8) years, P < 0.05), and a markedly enlarged left atrium (47.3 ± 2.9) mm vs. (42.1 ± 4.5) mm, P < 0.05). There were no significant differences in gender, age, body mass index and left ventricular function between the two groups. Ibutilide significantly prolonged the average wavelength of the AF wave (171.8 ± 29.5) ms vs. (242.0 ± 40.0) ms, P < 0.001). Two hours after ibutilide treatment, the QT interval was significantly shortened (421.0 ± 24.7) ms vs. (441.0 ± 37.4) ms, P < 0.05). No cases of serious arrhythmias or other adverse reactions were found.
A single dose of ibutilide for conversion of persistent or permanent AF after radiofrequency ablation is safe and effective.
Chinese medical journal 03/2011; 124(5):710-3. · 0.86 Impact Factor
