A comparative study of pericardial effusion and pleural effusion after cryoballoon ablation or radiofrequency catheter ablation of atrial fibrillation.

INTRODUCTION: The incidence and clinical outcome of pericardial and pleural effusion after cryoballoon ablation (CBA) or radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) have not been fully investigated. METHODS: A total of 60 patients with paroxysmal AF were treated with either CBA (n = 30) or RFCA (n = 30) groups, with assessment of serum troponin I level, left atrial pulmonary vein computed tomography (CT) angiography and echocardiography within 24 hours before ablation, and serum troponin I level at 12 hours, and chest CT and echocardiography within 24 hours postablation. Repeat chest CT was performed 1 month after the index procedure in patients with pericardial or pleural effusion. RESULTS: With similarly distributed baseline characteristics, the CBA group relative to the RFCA group had postablation: higher serum troponin I level (13.48 vs 1.84 µg/L, P < .001); similarly high pericardial effusion rates on chest CT (80% vs 93.3%, P > .05), with chest CT yielding significantly higher detection rate than echocardiography; similarly high pleural effusion rates on chest CT (73.3% vs 80%, P > .05); and smaller maximum depths on chest CT cross-section of pericardial effusion (5.21 ± 3.37 vs 7.13 ± 2.68 mm, P < .05) and pleural effusion bilaterally (left: 4.16 ± 4.90 vs 6.96 ± 5.42 mm; right: 5.04 ± 4.46 vs 7.55 ± 4.95 mm, both P < .05). The effusions self-resolved within a mean period of 1 month. CONCLUSIONS: Both CBA and RFCA were associated with high rates of pericardial and pleural effusion, with RFCA yielding numerically higher incidence and significantly higher effusion extent, and chest CT significantly higher detection rates than echocardiography.

[Clinical characteristics and long-term outcome of non-pulmonary vein foci ablation in patients with paroxysmal atrial fibrillation].

OBJECTIVE: To evaluate the clinical characteristics and long-term results of non-pulmonary veins (PV) trigger ablation in patients with paroxysmal atrial fibrillation (AF). METHODS: Eighty-six patients [48 men, mean age (52.3 ± 10.2) years] were included in the study. Circumferential pulmonary vein antrum isolation guided by a 3-D mapping system was performed. Aggressive high right atrium programmed stimulation and burst pacing were made before and after isoproterenol infusion. Additional ablation was performed if other trigger foci were found or other sustained tachycardias could be induced. RESULTS: PV triggers were observed in 59 patients (group I), and non-PV triggers were observed in 27 patients (group II), 12 non-PV triggers were identified during the first procedure. Among them, one was located in the roof of left atrium, 11 were originated from superior vena cava. After a mean follow-up of [37.1 ± 10.4 (range 15-60)] months, the AF recurrence rate was significantly higher in the Group II than in the Group I (55.5% vs. 20.3%, P = 0.001). The number of performed ablation was also significantly in group II than in group I higher difference (1.7 ± 0.8 vs. 1.1 ± 0.4, P < 0.001). In the group II, 15/15 (100%) patients had a repeated ablation procedure for AF recurrence, and 15 patients had new non-PV foci after isoproterenol infusion which were originated from the superior vena cava (n = 11) and coronary sinus (n = 2), respectively. After the second ablation procedure, AF recurrence was observed in three patients, two patients accepted third procedure, the non-PV triggers were located in left atrial septum and coronary sinus, and one patient accepted fourth procedure, the non-PV foci was located in left posterior wall. CONCLUSIONS: Non-PV foci may occur at any age and the main area is located in the super vena cava, Non-PV serves as a major cause of AF recurrence after successful PVAI.

[Catheter ablation of epicardial accessory pathway associated with coronary sinus musculature].

OBJECTIVE: To report the single-center clinical experience of catheter ablation of epicardial accessory pathway associated with coronary sinus musculature. METHODS: The data of 721 cases of left sided accessory pathway ablation were retrospectively analyzed. Ablation in the coronary sinus was performed in 17 (2.4 %) cases [11 males, mean age (37 ± 11) years]. RESULTS: Among the 17 cases, the accessory pathway was successfully ablated in middle cardiac vein and posterior lateral coronary sinus in 11 and 6 cases, respectively. Deverticulum of middle cardiac vein was seen in 2 cases. Mean time required to block the accessory pathway was (4.7 ± 2.7) s. An accessory pathway potential could be recorded at the target site in 10 out of 17 patients (59%). During a mean (21 ± 16) months follow up, only one patient experienced recurrence who was successfully cured by a second ablation session. No procedure related complication was reported. CONCLUSION: About 2.4% of left accessory pathway may have epicardial connection locating at middle cardiac vein or lateral part of the coronary sinus and require epicardial ablation. The epicardial ablation is safe and effective, warrants an excellent long-term results.

[Efficacy of catheter radiofrequency ablation for the treatment of ventricular arrhythmia storm post cardioverter-defibrillators implantation].

OBJECTIVE: To evaluate the acute and long-term effects of catheter radiofrequency ablation for the treatment of ventricular arrhythmia storm (VAS) post implantable cardioverter-defibrillators (ICD) implantation. METHODS: Acute and long-term effects of catheter radiofrequency ablation for the treatment of VAS post ICD implantation were retrospectively assessed in 11 patients from September 2008 to August 2011. RESULTS: A total of 15 ablation procedures were performed in 11 patients. Six ablation procedures were performed through epicardial approach. In 9 patients, 20 types of ventricular tachycardia (VT) (including 20% hemodynamically unstable VT) were induced during the procedures [mean cycle length (384 ± 141) ms] and polymorphic ventricular tachycardia were induced in 7 patients. The average X-ray fluoroscopy time and procedural time were (26 ± 17) min and (189 ± 60) min, respectively. Complete success, partial success, and failure rates immediately post catheter radiofrequency ablation were 46.7% (7/15), 26.7% (4/15) and 26.7% (4/15), respectively. All patients are alive at follow-up[(2.45 ± 9.6) months after the last catheter ablation] and the complete success, partial success, and failure rates during follow-up were 72.7% (8/11), 9.1% (1/11) and 18.2% (2/11), respectively. CONCLUSION: VAS can be effectively treated by catheter radiofrequency ablation in patients post ICD implantation.

[Catheter ablation of focal atrial tachycardia:the topographic distribution and long-term outcome].

OBJECTIVE: To explore the topographic distribution and long-term outcome of catheter ablation for focal atrial tachycardia (AT). METHOD: The data of 207 patients who underwent electrophysiologic study for AT were retrospectively analyzed. RESULTS: A total of 200 AT were identified in 185 patients. The most common site for AT was ostium of the coronary sinus (23.8%), followed by crista terminalis (20.5%), perinodal area (20.0%), cava vena (17.8%), annulus (13.0%), and appendage (10.3%). Eighty percent AT originated from the right atrium, 17.8% originated from the left atrium. AT originated from the left atrium was more common in male than in female (25.0% vs. 13.3%, P = 0.042), while AT originated from the right atrium was more common in female than in male (69.4% vs. 86.7%, P = 0.004). Among the 185 patients, acute success ablation rate was 93.5% (n = 173). The acute success rate in the conventional mapping group was lower than that in the three-dimensional mapping group (79.3% vs. 96.5%, P < 0.01). During a median of 36 months follow up, the AT recurred in 20 patients (success ablation rate 88.4%). Success ablation rate was similar between the conventional mapping group and the three-dimensional mapping group (P > 0.05). CONCLUSIONS: Focal AT commonly originates from ostium of coronary sinus, crystal terminalis, perinodal area, and cava veins. There is a gender related difference in the distribution of focal AT. The radiofrequency catheter ablation yields a satisfying success rate and very low complication rate and could be the first line choice for treating ATs in experienced electrophysiological center.

[Clinical characteristics of congenital ventricular aneurysm and diverticula in inland China].

OBJECTIVE: To summarize the clinical characteristics of congenital ventricular aneurysm and diverticula in inland China. METHODS: To identify the literature of congenital aneurysm and diverticula from Wanfang, China National Knowledge Infrastructure (CNKI) and PubMed databases, and to analyze the clinical characteristics of congenital aneurysm and diverticula from January of 2001 to December of 2009. RESULTS: A total of 116 patients [78 men, 1 - 80 (33.5 ± 21.3) years old] with congenital aneurysm or diverticula were included in 109 articles. Twenty-five patients (13 men) were congenital ventricular aneurysm, including a family of 4 patients. Ninety-one patients (65 men) were congenital ventricular diverticula. One hundred patients were detected by echocardiography during medical examination, 34 patients combined with other cardiac anomalies, 4 of which with extracardiac structures. There were 8 patients with ventricular arrhythmia, 8 patients with thrombosis, 2 patients died of cardiac rupture, 4 patients died of sudden death, surgical operation was performed in 46 patients and 3 patients received ablation procedure. All patient did not receive implantable cardioverter defibrillator (ICD) implantation. CONCLUSIONS: Congenital ventricular aneurysm or diverticulum is a rare cardiac malformation. Most congenital left ventricular aneurysms and diverticula are asymptomatic and detected by echocardiography. Congenital ventricular aneurysm or diverticulum may cause ventricular tachycardia, ventricular wall rupture, systemic embolization or sudden death, which had to be treated individually.

Right-sided free wall accessory pathway refractory to conventional catheter ablation: lessons from 3-dimensional electroanatomic mapping.

INTRODUCTION: the aim of this study was to delineate the electroanatomic substrates of right-sided free wall (RFW) accessory pathways (APs) that were refractory to conventional catheter ablation utilizing 3-dimensional (3-D) mapping. METHODS AND RESULTS: eleven patients with RFW APs that failed initial conventional catheter ablation(s) by a mean of 1.9 ± 0.5 attempts were enrolled in the study. Electroanatomic mapping of the right atrium was performed during orthodromic reciprocating tachycardia in 3 patients and right ventricular pacing in 8 patients. The earliest atrial activation site, which represented the atrial insertion of the AP, was separated from the tricuspid annulus by an average of 14.3 ± 3.9 mm, and the local activation time was 27.8 ± 17.0 ms earlier than that of the corresponding annular point. One patient exhibited an AP with wide branching on the atrial side. RF ablation with an irrigated catheter successfully interrupted AP conduction in all patients without complications. CONCLUSIONS: RFW APs resistant to conventional catheter ablation might be due to unique anatomic AP features such as more epicardial course at the annulus level with atrial insertion distant from the tricuspid annulus. Electroanatomic mapping is helpful to accurately localize the atrial insertion sites of these APs and facilitates catheter ablation.

[The anti-apoptotic effects of N-acetylcysteine in neonatal rat cardiomyocytes underwent hypoxia-reoxygenation injury].

OBJECTIVE: To evaluate the effects of N-acetylcysteine (NAC) on hypoxia-reoxygenation (H/R) injury induced apoptosis in neonatal rat cardiomyocytes. METHODS: Neonatal rat cardiomyocytes were cultured for 48 h and then randomized into control group, H/R group and H/R + NAC group. Cardiomyocytes underwent hypoxia for 6 h, reoxygenation for 72 h in the absence (H/R group) or presence (H/R + NAC group) of NAC (100 micromol/L). Cell viability was assayed with trypan blue staining. Early stage of apoptosis was detected by flow cytometry with Annexin V, late stage of apoptosis was assessed by TUNEL staining. ROS in culture medium was assayed by Image-iT(TM) LIVE green reactive oxygen species detection kit.bcl2 and bax mRNA levels were determined by real-time quantitative PCR (RT-PCR). bcl2, bax, p38 and pp38 protein levels were measured by Western blot. RESULTS: The percentage of viable cardiomyocytes (93.5%, 74.9%, 89.9%) was significantly reduced while percentage of early stage of apoptotic cardiomyocytes (6.5%, 25.2% and 11.1%) and late stage of apoptotic cardiomyocytes (3.5%, 33.5% and 13.5%) were significantly increased in H/R group compared to control group and these changes could be largely reversed by NAC (all P < 0.01). Significantly increased ROS generation in H/R group could also be attenuated by NAC (P < 0.01). The band density ratio of pp38 and p38 was significantly upregulated in H/R group (13.4 vs. 3.89), the mRNA and protein expressions of bcl2 were significantly lower and bax expressions were significantly higher in H/R group than those in control group and these changes could also be attenuated by NAC. CONCLUSION: NAC significantly reduced apoptosis through inhibiting the phosphorylation of p38 signal pathway.

Premature ventricular contractions originating from the right ventricular outflow tract: three-dimensional distribution of the target sites and their electrocardiographic characteristics.

1. The purpose of the present study was to explore the relationship between electrocardiogram (ECG) patterns of right ventricular outflow tract (RVOT) premature ventricular contractions and the three-dimensional distribution of the target sites. 2. Thirty-three consecutive patients were included in the study. The target sites were identified by non-contact mapping and confirmed by successful ablation. The distribution of the target sites in the three-dimensional reconstructed geometry of the RVOT was classified in three directions: (i) anterior (A)/posterior (P); (ii) free wall (F)/septal (Se); and (iii) superior (Su)/inferior (I). The ECG characteristics were then analysed according to the three-dimensional distribution of the target sites. 3. The following indices were helpful to identify the position of the target site: (i) QRS duration (> or = 150 msec = F; < 150 msec = Se; P < 0.05); (ii) the R wave pattern in the inferior leads (RR' or Rr' = F; R = Se; P < 0.05); (iii) the R wave amplitude in the inferior leads (high = Se; low = F; P < 0.05); (iv) the initial r wave width in lead V(1) (wide = F; narrow = Se; P < 0.05); (v) the QS wave amplitude in aVR and aVL (if aVR < aVL, A; if aVR > or = aVL, P; P < 0.05); and (vi) the initial r wave amplitude in lead V(1) and V(2) (if V(1) > or = 0.15 mV and V(2) > or = 0.3 mV, Su; if V(1) < 0.15 mV or V(2) < 0.3 mV, I; P < 0.05). 4. In conclusion, the ECG characteristics were associated with target site locations in all three directions.

[Prevalence of Epsilon wave in patients with arrhythmogenic right ventricular cardiomyopathy].

OBJECTIVE: To investigate the prevalence of Epsilon wave in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: The epsilon wave was detected in 32 patients [24 men, mean age (42.3 +/- 13.3) years] with ARVC using three different electrocardiography (ECG) recording methods: standard twelve leads ECG (S-ECG), right precordial leads ECG (R-ECG) and Fontaine bipolar precordial leads ECG (F-ECG). The Epsilon wave was defined as wiggler, small spike wave and smooth potential between the end of the QRS complex and the beginning of the ST segment. RESULTS: Epsilon wave was detected in 37.5%, 37.5% and 50.0% patients with ARVC by S-ECG, R-ECG and F-ECG respectively. The detection rates derived from the three recording methods were similar (P > 0.05). The Epsilon wave was only detectable by S-ECG in one case, by R-ECG in three cases, and by F-ECG in five cases. The detection rate of Epsilon wave was 50.0% by combined use of S-ECG and R-ECG (SR-ECG), 56.3% by combined use of S-ECG and F-ECG (SF-ECG), and 65.6% by combined use of the three recording methods (SRF-ECG). The detection rate was significantly higher by SF-ECG (56.3%) and SRF-ECG (65.6%) than by S-ECG alone (37.5%, all P < 0.05). Most Epsilon waves detected by the S-ECG, R-ECG and F-ECG were small spiked waves. CONCLUSION: Combined use of S-ECG, F-ECG and R-ECG could increase the detection rate of Epsilon wave in patients with ARVC.

Electrical and histological remodeling of the pulmonary vein in 2K1C hypertensive rats: Indication of initiation and maintenance of atrial fibrillation.

OBJECTIVE: Hypertension is a significant risk factor for atrial fibrillation (AF). The role of pulmonary vein (PV) remodeling in the mechanistic association between hypertension and AF is not definitive. In this study, we aimed to identify changes in the electrophysiology and histology in PVs in two-kidney, one-clip (2K1C) hypertensive rats. METHODS: Fifty male Sprague-Dawley rats were classified into the 2K1C and sham-operated groups. The systolic blood pressure was measured every 2 weeks. The left atrial diameter was measured by transthoracic echocardiography. Left superior PV (LSPV) and left atrial (LA) fibrosis was evaluated by Masson's trichrome staining. The expression of fibrosis markers [angiotensin II (Ang II), transforming growth factor-ß1 (TGF-ß1), matrix metalloproteinase-2 (MMP-2), and collagen I (Col I)] and ion channels [Kir2.1, Kir2.3, Cav1.2, and Nav1.5] in LSVP was quantified by western blot. Conventional microelectrodes were used to record the action potential duration at 90% repolarization (APD90) and effective refractory period (ERP) in isolated LA. RESULTS: At 4 months, the 2K1C hypertensive rats developed LA dilation. Col deposition in LSPV and left atrium and expression of TGF-ß1, MMP-2, and Col I in LSPV were significantly increased in 2K1C hypertensive rats. In addition, hypertension reduced the expression of Nav1.5 and Kir2.1, although there were no significant differences in APD90; ERP; and expression of Ang II, Kir2.3, and Cav1.2 between the two groups. CONCLUSION: Hypertension may lead to changes in the electrophysiology and histology of rats PVs, which is characterized by significant reduction in the expression of Nav1.5 and Kir2.1 and increase in interstitial fibrosis. These observations may clarify the role of PVs in the mechanistic association between hypertension and AF.

Hepatocyte growth factor modification enhances the anti-arrhythmic properties of human bone marrow-derived mesenchymal stem cells.

BACKGROUND/AIMS: Chronic myocardial infarction (MI) results in the formation of arrhythmogenic substrates, causing lethal ventricular arrhythmia (VA). We aimed to determine whether mesenchymal stem cells (MSCs) carrying a hepatocyte growth factor (HGF) gene modification (HGF-MSCs) decrease the levels of arrhythmogenic substrates and reduce the susceptibility to developing VA compared with unmodified MSCs and PBS in a swine infarction model. METHODS: The left descending anterior artery was balloon-occluded to establish an MI model. Four weeks later, the randomly grouped pigs were administered MSCs, PBS or HGF-MSCs via thoracotomy. After an additional four weeks, dynamic electrocardiography was performed to assess heart rate variability, and programmed electrical stimulation was conducted to evaluate the risk for VA. Then, the pigs were euthanized for morphometric, immunofluorescence and western blot analyses. RESULTS: The HGF-MSC group displayed the highest vessel density and Cx43 expression levels, and the lowest levels of apoptosis, and tyrosine hydroxylase (TH) and growth associated protein 43 (GAP43) expression. Moreover, the HGF-MSC group exhibited a decrease in the number of sympathetic nerve fibers, substantial decreases in the low frequency and the low-/high- frequency ratio and increases in the root mean square of successive differences (rMSSD) and the percentage of successive normal sinus R-R intervals longer than 50 ms (pNN50), compared with the other two groups. Finally, the HGF-MSC group displayed the lowest susceptibility to developing VA. CONCLUSION: HGF-MSCs displayed potent antiarrhythmic effects, reducing the risk for VA.

Myocardial injury resulting from radiofrequency catheter ablation: comparison of circumferential pulmonary vein isolation and complex fractionated atrial electrograms ablation.

BACKGROUND: Radiofrequency catheter ablation (RFCA) necessarily produces an area of myocardial necrosis. However, the difference of the extent of myocardial injury between circumferential pulmonary vein isolation (CPVI) and complex fractionated atrial electrograms (CFAE) ablation in patients with atrial fibrillation (AF) has not been investigated before. METHODS: Twenty-nine consecutive male patients (n = 29) with either paroxysmal or persistent AF were selected for CPVI or CFAE ablation. The CPVI or CFAE ablation was performed with a three-dimensional electroanatomical mapping system (CARTO). Serum cardiac biomarkers, for example, cardiac troponin T (cTnT), aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase myocardial bound (CKMB) were determined by the Elecsys STATE immunoassay. Cardiac structure and function were measured with echocardiography. RESULTS: Echocardiography showed that there was no significant difference of atrioventricular structure or function parameters between the CPVI group and the CFAE ablation group. Serum cTnT showed a significant increase in the CFAE ablation group over the CPVI group at 12 and 24 hours after the procedure (P < 0.05, respectively), and then it was reduced to a normal level after 48 hours. Serum AST showed a significant increase in the CFAE ablation group over the CPVI group at post-procedure, 4 and 12 hours after the procedure (P < 0.05, respectively), and then it reached to a normal level after 24 hours. There was no significant difference in LDH, CK, or CKMB levels between the CFAE ablation group and the CPVI group at any time point (P > 0.05). CONCLUSIONS: cTnT and AST other than LDH, total CK or CKMB activity significantly increased more in the CFAE ablation group than the CPVI group. However, the difference of the serum levels of cTnT, AST between two groups was temporary.