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ABSTRACT: BACKGROUND: Catheter ablation of persistent atrial fibrillation (AF) has been performed with varying results using a combination of different techniques. We sought to evaluate the efficacy of additional linear lesion and defragmentation of left atrium (LA). METHODS: A cohort of 169 patients with persistent AF was studied. Ablation was performed following a sequential strategy consisted of circumferential pulmonary vein isolation (CPVI), LA roof linear ablation, posterior mitral area, coronary sinus and cavotricuspid isthmus, and complex fractionated electrograms ablation. RESULTS: During a mean follow-up of 15±8months after a single procedure, 84 (50%) patients were in sinus rhythm, 34 (20%) had an AF recurrence and 51(30%) developed atrial tachycardias (ATs). Repeat procedures were performed in 24 recurrent AF and 46 AT patients. A total of 81 different ATs were mapped and ablated in 46 AT patients, characterized as focal for 45 and macroreentry for 36 ATs. Most of the ATs were likely to be attributed to the previous lesions by an analysis of substrate and activation mapping in the redo procedure and a review of the lesions placed in the initial procedure. Overall, 75 (93%) ATs were ablated successfully. Procedural complications occurred in 11 of the 239 procedures. After a mean follow-up of 20±9months, 128 (76%) patients were free of arrhythmias after the final procedure. CONCLUSIONS: CPVI supplemented by linear ablation and defragmentation does not seem to improve the overall success rate of persistent AF. The efficacy of linear ablation and defragmentation might be diluted by their proarrhythmic effects.
International journal of cardiology 10/2012; · 7.08 Impact Factor
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ABSTRACT: Slow Zone in CTI-Dependent Flutter After Atriotomy.
Earlier studies have shown that the slow conduction zone in patients with cavotriscuspid (CTI)-dependent atrial flutter without prior surgery (NS-AFL) is the CTI. However, the location of this slow zone in patients with CTI-dependent flutter and a prior atriotomy has not been formally studied. Identification of the slow zone in patients with prior atriotomy and CTI-dependent atrial flutter (PA-AFL) and comparison with NS-AFL may have important clinical implications.
Seventeen consecutive patients with PA-AFL and 17 consecutive patients with NS-AFL were included. Conduction velocity (CV) was measured using 3-dimensional mapping in 3 areas around the TVA. These regions were defined as the CTI area from lateral inferior vena cava orifice to coronary sinus ostium (region I), mid- to upper-septum (S), and free wall (F). In region F, the CV was much slower in PA-AFL than in NS-AFL patients (0.43 ± 0.13 vs 0.76 ± 0.26 m/s, P < 0.01). However, region I was slower in NS-AFL than PA-AFL (0.57 ± 0.18 m/s vs 0.84 ± 0.24 m/s, P < 0.01). In all PA-AFL patients, the slow zone was in region F. But in most (11/17) NS-AFL patients the slow zone was in region I. There was no significant difference in CV in region S between the 2 groups.
Unlike NS-AFL, CTI in PA-AFL displays relatively normal conduction but the slow zone is on the free wall. This arrhythmogenecity of atriotomy may perhaps be avoided if the incisional line were altered to extend to the TV. (J Cardiovasc Electrophysiol, Vol. 23, pp. 988-995, September 2012).
Journal of Cardiovascular Electrophysiology 08/2012; 23(9):988-95. · 3.06 Impact Factor
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ABSTRACT: Ablation in the noncoronary aortic cusp (NCC) potentially has a role in the treatment of perinodal atrial tachycardias (ATs). The objective of the study was to characterize clinical and electrophysiological properties of perinodal ATs between two groups of requiring and not requiring NCC ablation.
A total of 113 patients with focal ATs who underwent electrophysiologic study and radiofrequency catheter ablation were enrolled in the study. The clinical and electrophysiological characteristics of ATs that need and not need NCC ablation were compared.
Totally 20 cases were revealed to have the focal ATs located in the perinodal area. Among them, only five cases (25%) warrant ablation in the NCC, whereas the remainder could be successfully eliminated by ablation from the endocardial right atrium at the perinodal region. There were no clinical and electrophysiological clues observed to have the potential to predict the true original site, including the activation mode, the three-dimensional mapping characteristics of earliest activation site in the right atrium, as well as the time of termination during the ablation in the perinodal area.
Approximately, one-fourth of the perinodal ATs warrant ablation in the NCC. However, no clinical and electrophysiological clues could predict the potential site of the perinodal ATs.
Pacing and Clinical Electrophysiology 06/2012; 35(7):811-8. · 1.35 Impact Factor
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ABSTRACT: Circumferential pulmonary vein antral isolation (PVAI) and atrial complex fractionated electrograms (CFEs) are both ablative techniques for the treatment of paroxysmal atrial fibrillation (PAF). However, data on the comparative value of these 2 ablation strategies are very limited.
We randomized 118 patients with drug-refractory PAF to receive PVAI ablation (n = 60) or CFE ablation (n = 58). For CFE group, spontaneous/induced AF was mapped using validated, automated software to guide ablation until all CFE areas were eliminated. For PVAI group, all 4 pulmonary vein antra were electrically isolated as confirmed by circular mapping catheter. Patients with spontaneous/inducible AF after the initial ablation procedure were crossed over to the other arms. After initial ablation procedure, AF persisted/inducible in 24/59 patients (41%), and 34/58 patients (59%) assigned to PVAI and CFE ablation, respectively (P = 0.05). Then 58 patients underwent PVAI + CFE ablation. After 22.6 ± 6.4 months, PVAI ablation group was more likely than CFE ablation group to achieve control of any AF/atrial tachycardia (AT) off drugs (43/60, 72% vs 33/58, 57%, P = 0.075) and lower recurrence rate of AT (11.9% vs 34.5%, P = 0.004). Patients who received CFE ablation alone (38%) had significantly lower overall success rate to achieve control of AF/AT off drugs compared with patients who received PVAI ablation (77%, P = 0.002) alone or PVAI + CFE ablation (69%, P = 0.008) due to higher recurrence rate of AT (50% vs 6% vs 13%, P < 0.01).
CFE ablation in PAF patients was associated with higher occurrence rate of postprocedure AT compared with PVAI ablation, whereby making it less likely to be a sole ablation strategy for PAF patients.
Journal of Cardiovascular Electrophysiology 05/2011; 22(9):973-81. · 3.06 Impact Factor
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ABSTRACT: There is a consistent understanding that the proarrhythmic effect of linear ablation in the left atrium body for atrial fibrillation (AF) always manifests as the macroreentry tachycardia. However, its genesis of localized reentry has been underestimated.
Among 90 persistent AF patients who had accepted linear ablation in the left atrium body, a total of 11 patients (12%) presented with a localized reentry (six men, mean age 59 ± 11 years) associated with previous ablation lines. Among the 11 patients, four were encountered during the index procedure for AF ablation and the remaining seven during the redo procedure for atrial tachycardias (ATs).
The ATs were all located at previously ablated lesion sites and manifested a centrifugal mode in both the activation mapping and pattern of the postpacing interval response. The mean tachycardia cycle length (TCL) of the localized reentrant ATs was 306 ± 73 ms. The target sites demonstrated low amplitude (0.17 ± 0.09 mV) continuous complex electrograms or long double potentials, covering 142 ± 57 ms (46 ± 12 % of the TCL). The localized reentrant tachycardias were all successfully eliminated by catheter ablation.
A novel type of the proarrhythmic effects of linear ablation in the left atrium for AF may manifest as localized reentrant ATs, as evidenced by the association of the site of origin with the prior lesions.
Pacing and Clinical Electrophysiology 04/2011; 34(8):919-26. · 1.35 Impact Factor
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Europace 02/2011; 13(7):1047-50. · 1.98 Impact Factor
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Hongwu Chen,
Bing Yang,
Weizhu Ju,
Fengxiang Zhang,
Xiaofeng Hou,
Chun Chen,
Lishang Zhai,
Jing Wang,
Kejiang Cao,
Minglong Chen,
Hung-Fat Tse
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ABSTRACT: The incidence and clinical implication of dissociated pulmonary vein (PV) electrical activities after circumferential antrum PV ablation for paroxysmal atrial fibrillation (AF) remains unclear.
A total of 196 patients with symptomatic paroxysmal AF who underwent circumferential antrum PV ablation were prospectively studied. Dissociated PV electrical activities were observed in 101 patients (Group 1), but absent in the remaining 95 patients (Group 2). There were no significant differences in the baseline clinical characteristics between them, except that Group 2 had a higher prevalence of hypertension (30 vs. 44%, P = 0.04). After 21.8 ± 7.9 months of follow-up, 148 had no recurrence of AF after the initial procedure. AF recurrence rate was significantly higher in Group 2 than in Group 1 (P = 0.023). Relapse of PV conduction was the major cause of AF recurrence in both groups (16/16 vs. 19/23, P = 0.08), and the overall procedural success rate after the redo ablation procedure was similar in the 2 groups (90 vs. 86%, P = 0.44). However, the total number of patients with non-PV foci was significantly higher in Group 2 than in Group 1 (12/95 vs. 2/101, P < 0.01).
Dissociated PV electrical activities might identify a subgroup of patients with relatively higher initial procedural success with circumferential PV antrum ablation.
Circulation Journal 11/2010; 75(1):73-9. · 3.77 Impact Factor
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ABSTRACT: Atrial tachycardia (AT) is commonly encountered after atrial fibrillation (AF) ablation. But no study exclusively on noncavotricuspid isthmus-dependent right AT (NCTI-RAT) post-AF ablation has been reported. The present study aims to describe its prevalence, electrophysiological mechanisms, and ablation strategy and to further discuss its relationship with AF.
From July 2006 to November 2009, 350 consecutive patients underwent catheter ablation for paroxysmal AF. A total of seven patients (2.0%) developed NCTI-RAT after left atrium ablation for AF. In these highly selected patients (two male, mean age 54 ± 11 years, mean left atrium diameter of 34 ± 7 cm), all had circumferential pulmonary vein isolation in their initial procedures and three of them had additional complex fractionated electrograms ablation in the left atrium and the coronary sinus.
Totally, nine NCTI-RATs were mapped and successfully ablated in the right atrium with a mean cycle length of 273 ± 64 ms in seven patients. Five ATs in three patients were electrophysiologically proved to be macroreentry and the remaining four were focal activation. All the ATs were successfully abolished by catheter ablation. After a mean follow-up of 29 ± 15 months post-AT ablation, all patients were free of AT and AF off antiarrhythmic drugs.
NCTI-RAT is relatively less common post-AF ablation. Totally, 2.0% of paroxysmal AF patients were revealed to have NCTI-RAT.
Pacing and Clinical Electrophysiology 11/2010; 34(4):391-7. · 1.35 Impact Factor
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ABSTRACT: Catheter ablation for atrial fibrillation (AF) has become a widely accepted procedure in most of the large cardiac centers throughout the world. However, little is known regarding the knowledge, attitude, and behavior (KAB) of AF patients undergoing radiofrequency catheter ablation (RFCA). Our purpose is to investigate the status and influencing factors of KAB in these patients.
We conducted a KAB survey utilizing specifically designed questionnaires among hospitalized AF patients undergoing RFCA from July 2008 to April 2009.
A total of 116 AF participants were enrolled and 113 were effective sample, the response rate was 97%. Only 47% of the participants answered questions regarding knowledge about AF correctly. Knowledge deficits were greater in male patients, poorly educated and first-time RFCA patients. With regard to attitude, 45% of participants considered daily pulse examination to be unnecessary. Higher knowledge scores, persistent AF and AF recurrence were positive predictors of attitude. Despite adherence to take medication was high, more than half of the participants demonstrated poor monitor behavior. Knowledge, attitude, and the number of previous attempts at RFCA were factors affecting the self-management behavior.
AF patients undergoing RFCA have knowledge deficits in general and there is a lack of consistency among their KAB. In order to establish a better attitude and self-management behavior, AF patients undergoing RFCA need comprehensive education by the KAB questionnaire according to the KAB theory.
Journal of Interventional Cardiac Electrophysiology 09/2010; 28(3):199-207. · 1.17 Impact Factor
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ABSTRACT: The involvement of connexins in regulating cell growth and death has recently been reported. We have investigated whether Cx43 (connexin43) contributes to MSC (mesenchymal stem cell) survival and improves therapeutic efficacy in MI (myocardial infarction). Genetically modified Cx43 MSCs were exposed to hypoxic conditions or injected intramyocardially into a rat MI model. MSCs overexpressing Cx43, with more Bcl-2 and phosphorylated Akt, but less Bax, were relatively tolerant to hypoxic injury. After transplantation, this Cx43 overexpression enhanced cell survival and reduced infarct size, improving contractile performance. Cx43 inhibition by SiRNA reversed the effects of Cx43 overexpression. Therefore, Cx43 may act as a potential target for improving the therapeutic efficacy of MSCs in ischaemic heart disease.
Cell Biology International 04/2010; 34(4):415-23. · 1.48 Impact Factor
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ABSTRACT: We analyzed the shape and distribution of epsilon waves by 3 various methods of electrocardiographic recording in patients with arrhythmogenic right ventricular cardiomyopathy.Thirty-two patients who met recognized diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy were included in this study (24 men and 8 women; mean age, 42.3 ± 12.9 yr). Epsilon waves were detected by standard 12-lead electrocardiography (S-ECG), right-sided precordial lead electrocardiography (R-ECG), and Fontaine bipolar precordial lead electrocardiography (F-ECG). We found 3 types of epsilon waves: wiggle waves, small spike waves, and smooth potential waves that formed an atypical prolonged R' wave. The most common configuration was small spiked waves. In some circumstances, epsilon waves were evident in some leads (especially in leads V(1) through V(3)), but notches were recorded in the other leads during the corresponding phase. These waves could be detected only by S-ECG in 1 patient, R-ECG in 3 patients, and F-ECG in 5 patients; the rates of epsilon-wave detection by these 3 methods were 38% (12/32), 38% (12/32), and 50% (16/32), respectively. However, the detection rate using combined methods was significantly higher than that by S-ECG alone (SF-ECG 56% vs S-ECG 38%, P = 0.0312; and SRF-ECG 66% vs S-ECG 38%, P = 0.0039). In addition, the rate of widespread T-wave inversion (exceeding V(3)) was significantly higher in patients with epsilon waves than in those without (48% vs 9%, P = 0.029), as was ventricular tachycardia (95% vs 64%, P = 0.019).These 3 electrocardiographic recording methods should be used in combination to improve the detection rate of epsilon waves.
Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2010; 37(4):405-11. · 0.65 Impact Factor
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Circulation Arrhythmia and Electrophysiology 12/2009; 2(6):e34-41. · 6.46 Impact Factor
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ABSTRACT: Several electrocardiographic (ECG) algorithms have been developed to identify the site of origin of ventricular premature contractions (VPCs) from right ventricular outflow tract (RVOT) based on pacemapping; however, their accuracy remains unclear.
We evaluated the accuracy of these algorithms in 52 consecutive patients (31 female, mean age 42.6+/-14.6 years) with successful radiofrequency ablation of RVOT-VPC as guided by 3D electroanatomical non-contact mapping (Ensite, St Jude Medical, USA) and compared with a newly proposed ECG algorithm. As guided by 3D electroanatomical mapping, the successful ablation sites of RVOT-VPC were RVOT septum (n=31), RVOT free wall (n=19), and His region (n=2). Retrospective evaluation in the initial 39 patients shows that the overall positive prediction value to identify a successful ablation site of this newly proposed ECG algorithm is 77.3% and is higher than the 73.3% by Ito et al., 73.3% by Joshi et al., and 53.8% by Dixit et al. (P>0.05). Prospective evaluation in the subsequent 13 patients also demonstrate similar high overall sensitivity (79.0%), specificity (92.7%), and positive prediction value (88.2%) to identify a successful ablation site with this newly proposed ECG algorithm.
On the basis of detail 3D electroanatomical mapping of successful ablation sites, a newly proposed ECG algorithm was developed to improve the sensitivity, specificity, and positive prediction value in identification of targeted ablation sites for RVOT-VPC.
Europace 10/2009; 11(9):1214-20. · 1.98 Impact Factor
