A comparative study on the clinical efficacy of percutaneous endoscopic lumbar discectomy and conventional open surgery in the treatment of lumbar disc herniation.

Objective: To analyze the efficacy of single-channel percutaneous endoscopic lumbar discectomy (PELD) and conventional open surgery in the treatment of lumbar disc herniation (LDH). Methods: This is a retrospective study. A total of 66 patients with LDH admitted to Tianjin Medical University from June 2017 to June 2018 were divided into two groups: the observation group (single-channel PELD) and the control group (posterior lumbar interbody fusion), with 33 cases in each group. The two groups were compared in terms of visual analogue scale(VAS), oswestry disability index (ODI), Japanese Orthopaedic Association Score(JOA), perioperative indicators, clinical efficacy, postoperative complications, changes in inflammatory factors and serum T lymphocyte subsets. Results: The operation time, incision length, intraoperative blood loss, time in bed, hospital stay in the observation group were all lower than those in the control group. At 7d after treatment, the improvement of ODI, VAS and JOA in the observation group were better than that in the control group. At the last follow-up, there was no significant difference in Cobb angle and lumbar lordosis angle between the two groups. The levels of serum IL-1, IL-6 and TNF-α in the observation group were lower than those in the control group. The degree of reduction of serum CD3+ and CD4+ in the observation group were higher than those in the control group. And the level of elevation of CD8+ in the observation group was lower than that in the control group. Moreover, there was no significant difference in CD4+/CD8+ level between the two groups. The excellent rate of surgical results in the observation group was higher than that in the control group. Complications occurred in both groups, with no significant difference between the two groups. Conclusions: Single-channel PELD can achieve superior clinical efficacy over conventional open surgery in the treatment of LDH.

Adjunctive percutaneous ablation targeting epicardial arrhythmogenic structures in patients of atrial fibrillation with recurrence after multiple procedures.

INTRODUCTION: Repeat ablation strategy for atrial fibrillation (AF) recurrence after multiple ablation procedures is known to be challenging. This study evaluated the insights of adjunctive ablation for epicardial arrhythmogenic substrates in those patients via a percutaneous epicardial approach. METHODS AND RESULTS: Thirty-five consecutive patients with AF/atrial tachycardia (AT) recurrence, who had two or more prior ablation procedures, were enrolled from September 2016 to December 2018. In addition to a standard endocardial approach, epicardial mapping and ablation were performed via a percutaneous subxiphoid access in the electrophysiology lab. Adjunctive epicardial ablations for left lateral ridge (LLR) were performed in 31 of 35 patients (88.6%) for efficient transmural lesions with pacing capture loss. Marshall Bundle (MB) potentials were documented on epicardial LLR in three patients and abolished by direct epicardial ablation. Bachmann's bundle (BB) was ablated as an epicardial conduction gap in four patients with a refractory anterior wall line. Two epicardial AT/AF triggers were detected followed by successful termination with epicardial ablation. No periprocedural complications occurred. About 23 of 35 patients (65.7%) remained free from AF/AT after 23.2 ± 9 months of the procedure. CONCLUSIONS: Patients with multiple failed prior AF procedures refractory to antiarrhythmic therapy might warrant a percutaneous epicardial mapping and ablation strategy, with adjunctive therapy for targeting LLR/MB, BB, and underlying epicardial triggers in addition to a standard endocardial approach.

Stereotactic body radiation therapy for refractory ventricular tachycardia secondary to cardiac lipoma: A case report.

We present the case of a 29-year-old man who developed ventricular tachycardia (VT) secondary to a cardiac lipoma located adjacent to the interventricular groove, which could not be fully resected. Antiarrhythmic drugs and endocardial and epicardial ablation failed to prevent VT recurrence. Finally, noninvasive stereotactic body radiation therapy (SBRT) targeting the lipoma was performed, with a total dose of 24 Gy delivered in three fractions. The number of VT episodes was reduced from 189/24 h before SBRT to 0 after the procedure. At 4-month follow-up, there were no signs of therapy-related complications. Our experience suggests that SBRT could emerge as a viable treatment option for patients with cardiac tumors who develop refractory ventricular arrhythmias.

Bioinformatics analysis of sex differences in arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease that exhibits sex differences on clinical presentation. The present study aimed to investigate the sex differences associated with ARVC by conducting an integrated bioinformatics analysis. The GSE29819 gene expression dataset was downloaded from the Gene Expression Omnibus database. The online analytical tool GEO2R was then used to screen for differentially expressed genes (DEGs), which were subsequently processed using enrichment analysis and protein­protein interaction (PPI) network construction. Functional annotation of the DEGs was determined using ClueGO. The PPI network was constructed with Search Tool for the Retrieval of Interacting Genes, and was visualized with Cytoscape to identify the modules and hub genes. Compared with the female group, a total of 1,188 DEGs, of which 915 were upregulated and 273 were downregulated, were identified in the male group. The enrichment analysis revealed that in KEGG pathways, the upregulated DEGs were substantially enriched in the 'nicotine addiction' pathways, whereas the downregulated DEGS were mainly enriched in the 'ECM­receptor interaction' and 'protein digestion and absorption' pathways. The PPI network contained 899 nodes and 1,627 edges, among which four significant modules were identified. In addition, kininogen 1, lysophosphatidic acid receptor 5, formyl peptide receptor (FPR) 2, adenylate cyclase 2, γ­aminobutyric acid type B receptor subunit 2, FPR1, hydroxycarboxylic acid receptor 1, prostaglandin E receptor 3, cannabinoid receptor 1 and proenkephalin were identified as the top 10 hub genes. The key genes and related pathways identified in this study provide genetic insight into the diversity in phenotypes between female and male patients with ARVC, and may facilitate therapeutic individualization.

MicroRNA Expression Profiles Identify Biomarker for Differentiating the Embolic Stroke from Thrombotic Stroke.

In order to identify potential biomarkers that distinguish the embolic stroke (ES) from thrombotic stroke (TS), a profile of microRNA expression was analyzed. The GSE60319 expression profile was downloaded from the Gene Expression Omnibus (GEO) database. The GEO2R was applied to screen for differentially expressed microRNAs (DEmiRNAs) between the embolic stroke group and thrombotic stroke group. The miRWalk was utilized to predict the target genes of DEmiRNAs. Genes associated with embolic stroke were downloaded from the Comparative Toxicogenomics Database. Cross reference of target genes to disease related genes was conducted to construct the DEmiRNA-gene network. The protein-protein interaction (PPI) network of overlapping genes was evaluated by STRING, using the MCODE and CytoHubba plugin of Cytoscape to identify the modules and hub genes. The enrichment of Kyoto Encyclopedia of Genes and Genomes (KEGG) in modules was performed. There were 30 microRNAs in total identified as DEmiRNAs between embolic stroke and thrombotic stroke groups, of which 8 were upregulated and 22 were downregulated. Among these differentially expressed miRNAs, miR-15a-5p, miR-17-5p, miR-19b-3p, and miR-20a-5p were significantly associated with an ES to TS. Using the miRWalk 3.0 online tool, target genes regulated by DEmiRNAs were predicted. In addition, disease related genes were predicted and compared with target genes of DEmiRNAs. 166 overlapped genes regulated by miR-15a-5p, miR-17-5p, miR-19b-3p, and miR-20a-5p were identified, suggesting their association with diseases that contributed to ES, mainly including atrial fibrillation, mitral valve stenosis, myocardial infarction, and aortic dissection. Therefore, miR-15a-5p, miR-17-5p, miR-19b-3p, and miR-20a-5p were promising candidate biomarkers for differentiating an ES from TS. The PPI network demonstrated that miR-15a-5p, miR-17-5p, miR-19b-3p, and miR-20a-5p were associated with an ES by mainly regulating "CCND1, E2F2, E2F3, ITCH, UBE4A, UBE3C, RBL2, FBXO31, EIF2C4, and EIF2C1". Furthermore, miR-15a-5p and miR-17-5p may function through "cell cycle, prostate cancer, and small cell lung cancer" while miR-19b-3p and miR-20a-5p function through "insulin resistance, hepatitis B, and viral carcinogenesis" and "vasopressin-regulated water reabsorption", respectively. However, these results were approached in the manner of bioinformatics analysis; therefore, further verification is required.

Impact of Anatomically Guided Ganglionated Plexus Ablation on Electrical Firing from Isolated Pulmonary Veins.

BACKGROUND: The mechanisms underlying atrial fibrillation (AF) initiation and pulmonary vein isolation (PVI) effectiveness remain unclear. Ganglionated plexus (GPs) have been implicated in AF initiation and maintenance. In this study, we evaluated the impact of GP ablation in patients with pulmonary vein (PV) firing after PVI. METHODS: Patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation therapy with PVI were screened. Among 840 cases over a 3.75-year period, 12 cases were identified with persistent PV firing (left = 4 and right = 8) after PVI was achieved and left atrial sinus rhythm restored. Adjacent GP ablation was performed anatomically and followed if necessary by additional PV ablation. RESULTS: In eight patients, PV firing was terminated during GP ablation outside of the circumferential ablation line. In one patient, additional PV ablation resulted in cessation of PV firing and in the remaining three patients, firing could not be terminated by GP ablation or additional PVI. CONCLUSION: GP ablation outside of wide antral circumferential line frequently results in the cessation of rapid firing from electrically isolated PVs. These observations suggest that interactions between left atrium and PV beyond electrical conduction warrant consideration in AF mechanisms.

Cadmium Activates Reactive Oxygen Species-dependent AKT/mTOR and Mitochondrial Apoptotic Pathways in Neuronal Cells.

OBJECTIVE: To examine the role of Cd-induced reactive oxygen species (ROS) generation in the apoptosis of neuronal cells. METHODS: Neuronal cells (primary rat cerebral cortical neurons and PC12 cells) were incubated with or without Cd post-pretreatment with rapamycin (Rap) or N-acetyl-L-cysteine (NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3'-kinase/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays. RESULTS: Cd-induced activation of Akt/mTOR signaling, including Akt, mTOR, p70 S6 kinase (p70 S6K), and eukaryotic initiation factor 4E binding protein 1 (4E-BP1). Rap, an mTOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/mTOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein (Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), and nuclear translocation of apoptosis-inducing factor (AIF) and endonuclease G (Endo G). CONCLUSION: Cd-induced ROS generation activates Akt/mTOR and mitochondrial pathways, leading to apoptosis of neuronal cells. Our findings suggest that mTOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.

Approaches to catheter ablation for persistent atrial fibrillation.

BACKGROUND: Catheter ablation is less successful for persistent atrial fibrillation than for paroxysmal atrial fibrillation. Guidelines suggest that adjuvant substrate modification in addition to pulmonary-vein isolation is required in persistent atrial fibrillation. METHODS: We randomly assigned 589 patients with persistent atrial fibrillation in a 1:4:4 ratio to ablation with pulmonary-vein isolation alone (67 patients), pulmonary-vein isolation plus ablation of electrograms showing complex fractionated activity (263 patients), or pulmonary-vein isolation plus additional linear ablation across the left atrial roof and mitral valve isthmus (259 patients). The duration of follow-up was 18 months. The primary end point was freedom from any documented recurrence of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure. RESULTS: Procedure time was significantly shorter for pulmonary-vein isolation alone than for the other two procedures (P<0.001). After 18 months, 59% of patients assigned to pulmonary-vein isolation alone were free from recurrent atrial fibrillation, as compared with 49% of patients assigned to pulmonary-vein isolation plus complex electrogram ablation and 46% of patients assigned to pulmonary-vein isolation plus linear ablation (P=0.15). There were also no significant differences among the three groups for the secondary end points, including freedom from atrial fibrillation after two ablation procedures and freedom from any atrial arrhythmia. Complications included tamponade (three patients), stroke or transient ischemic attack (three patients), and atrioesophageal fistula (one patient). CONCLUSIONS: Among patients with persistent atrial fibrillation, we found no reduction in the rate of recurrent atrial fibrillation when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary-vein isolation. (Funded by St. Jude Medical; ClinicalTrials.gov number, NCT01203748.).

Non-pulmonary vein foci induced before and after pulmonary vein isolation in patients undergoing ablation therapy for paroxysmal atrial fibrillation: incidence and clinical outcome.

OBJECTIVE: To evaluate the incidence and clinical outcome of adenosine triphosphate (ATP) plus isoproterenol (ISP)-induced non-pulmonary vein (PV) foci before and after circumferential PV isolation (CPVI) during index ablation in patients with paroxysmal atrial fibrillation (PAF). METHODS: In 80 consecutive patients undergoing catheter ablation for drug-refractory, symptomatic PAF at our hospital from April 2010 to January 2011, atrial fibrillation (AF) was provoked with ATP (20 mg) and ISP (20 µg/min) administration before and after CPVI. The spontaneous initiation of AF was mapped and recorded. RESULTS: Before ablation, AF mostly originating from PVs (PV vs. non-PV, 36/70 vs. 3/70; P<0.01) was induced in 39 patients with sinus rhythm. CPVI significantly suppressed AF inducibility; however, more non-PV foci were provoked (post-CPVI vs. pre-CPVI, 13/76 vs. 3/70; P=0.016). Patients with pre- and post-CPVI induced AF (n=49) were divided according to non-PV foci being induced (group N, n=17) or not (group P, n=32). After mean (19.2±8.2) months follow-up, 88.2% (15/17) and 65.6% (21/32) of patients in groups N and P, respectively, were free from AF recurrence (P=0.088). CONCLUSIONS: ATP+ISP administration effectively provokes non-PV foci, especially after CPVI in PAF patients. Although in this study difference did not achieve statistical significance, supplementary ablation targeting non-PV foci might benefit clinical outcome.

Marked suppression of pulmonary vein firing after circumferential pulmonary vein isolation in patients with paroxysmal atrial fibrillation: is pulmonary vein firing an epiphenomenon?

INTRODUCTION: Rapid firing in pulmonary veins (PVs) is a leading cause of paroxysmal atrial fibrillation. We hypothesized that PV firing (PV-F) should continue after circumferential PV isolation (CPVI) because the PV tissue responsible for PV-F remains intact. METHODS AND RESULTS: In Group-1 (n = 92), isoproterenol (ISP) and adenosine triphosphate (ATP) were co-administered to provoke PV-F before and after CPVI. The site of rapid focal discharge that initiated atrial fibrillation (AF) defined PV-F versus non-PV-F. Additional 17 patients with PV-F induced by ISP+ATP before CPVI were enrolled into Group-2 and various pacing maneuvers were used in conjunction to ISP+ATP to provoke PV-F after CPVI. In Group-1, AF was induced in 47/81 (58.0%) and 16/88 (18.2%) patients before and after CPVI, respectively (P < 0.01). Before CPVI, 43/47 (91.5%) of the rapid firing originated from PV. After successful CPVI, 88/92 patients were in sinus rhythm and non-PV-F was induced in 14/88 patients. PV-F was induced in 2/88 patients, which was eliminated by ganglionated plexus ablation outside the CPVI line. In Group-2, various pacing maneuvers with ISP+ATP only induced PV-F in 1/17 patients after CPVI. CONCLUSION: Marked suppression of PV-F after CPVI strongly suggests that the real source of PV-F is located in the atrium. PV-F may be an epiphenomenon.

Cadmium-induced apoptosis in primary rat cerebral cortical neurons culture is mediated by a calcium signaling pathway.

Cadmium (Cd) is an extremely toxic metal, capable of severely damaging several organs, including the brain. Studies have shown that Cd disrupts intracellular free calcium ([Ca(2+)]i) homeostasis, leading to apoptosis in a variety of cells including primary murine neurons. Calcium is a ubiquitous intracellular ion which acts as a signaling mediator in numerous cellular processes including cell proliferation, differentiation, and survival/death. However, little is known about the role of calcium signaling in Cd-induced apoptosis in neuronal cells. Thus we investigated the role of calcium signaling in Cd-induced apoptosis in primary rat cerebral cortical neurons. Consistent with known toxic properties of Cd, exposure of cerebral cortical neurons to Cd caused morphological changes indicative of apoptosis and cell death. It also induced elevation of [Ca(2+)]i and inhibition of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase activities. This Cd-induced elevation of [Ca(2+)]i was suppressed by an IP3R inhibitor, 2-APB, suggesting that ER-regulated Ca(2+) is involved. In addition, we observed elevation of reactive oxygen species (ROS) levels, dysfunction of cytochrome oxidase subunits (COX-I/II/III), depletion of mitochondrial membrane potential (ΔΨm), and cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase (PARP) during Cd exposure. Z-VAD-fmk, a pan caspase inhibitor, partially prevented Cd-induced apoptosis and cell death. Interestingly, apoptosis, cell death and these cellular events induced by Cd were blocked by BAPTA-AM, a specific intracellular Ca(2+) chelator. Furthermore, western blot analysis revealed an up-regulated expression of Bcl-2 and down-regulated expression of Bax. However, these were not blocked by BAPTA-AM. Thus Cd toxicity is in part due to its disruption of intracellular Ca(2+) homeostasis, by compromising ATPases activities and ER-regulated Ca(2+), and this elevation in Ca(2+) triggers the activation of the Ca(2+)-mitochondria apoptotic signaling pathway. This study clarifies the signaling events underlying Cd neurotoxicity, and suggests that regulation of Cd-disrupted [Ca(2+)]i homeostasis may be a new strategy for prevention of Cd-induced neurodegenerative diseases.

Regional ganglionated plexus ablation eliminated rapid firing in an electrically isolated pulmonary vein.

Atrial fibrillation (AF) was initiated by rapid firing from left superior pulmonary vein (PV) by administration of isoproterenol (ISP) and adenosine triphosphate (ATP) before ablation. After successful isolation of all PVs, ISP and ATP were administered again. PVs were still isolated but an episode of rapid firing was observed inside the left PV isolation line during sinus rhythm. Radiofrequency energy was then delivered to the areas of superior left ganglionated plexus (GP) and inferior left GP. Then, PV firing could no longer be initiated. It suggests additional GP ablation may have additional benefit to circumferential PV isolation, to reduce the incidence of AF recurrence.

Dissociated pulmonary vein rhythm may predict the acute pulmonary vein reconnection post-isolation in patients with paroxysmal atrial fibrillation.

AIMS: Dissociated pulmonary vein rhythm (PVD) has been taken as a signal of PV isolation, but has been questioned recently; we assessed the relationship between PVD and acute PV reconnection after PV isolation in this study. METHODS AND RESULTS: Eighty-five consecutive patients (52 males; mean age 59±11 years) were referred for catheter ablation of drug-refractory paroxysmal AF. Following PV isolation, the presence and cycle length of PVD were recorded. Pulmonary veins were classified into veins with PVD (Group 1) and veins without PVD (Group 2). Adenosine triphosphate (ATP) was then injected during isoproterenol infusion to reveal dormant conduction gap(s), and PVs were further remapped at 30 min post-isolation. Totally, PVD was observed in 68% (58 of 85) of patients and 34.7% (112 of 323) of PVs. Seventy-nine (24.5%) PVs were found acutely reconnected, including 48 veins revealed by ATP induction [ATP(+)PV] and 64 veins by reassessment after 30 min post-isolation [Time(+)PV]. Time(+)PVs were observed more frequently in Group 1 than those in Group 2 (31.3 vs. 13.7%, P<0.01), but no significant difference was found in the occurrence of ATP(+)PVs between Group 1 and Group 2 (17.9 vs. 13.3%, P=0.27). The sequences of the PVD and the acutely reconnected PV potential were similar in 87.5% of veins. After PV re-isolation, 70% (28 of 40) of previously documented PVD disappeared. CONCLUSION: The occurrence of PVD after PV isolation was closely related to the acute PV reconnection after 30 min post-isolation.

ATP revealed extra pulmonary vein source of atrial fibrillation after circumferential pulmonary vein isolation.

Noninducibility of atrial fibrillation (AF) by additional electrograms-guided ablation may benefit the clinical outcome. This report illustrates the effect of adenosine triphosphate (ATP) injection on AF inducibility after pulmonary vein (PV) isolation. AF was triggered twice by ATP without PV reconnection. Meanwhile, complex fractionated atrial electrograms (CFAEs) were observed, and ablation targets on these sites appeared to be essential to the AF elimination. It suggests that CFAEs may contribute to the initiation of some AF. ATP may be useful to induce AF after proven PV isolation, and further ablation might be necessary to ensure efficacy after circumferential PV isolation.

Early detection of pulmonary vein reconnection after isolation in patients with paroxysmal atrial fibrillation: a comparison of ATP-induction and reassessment at 30 minutes postisolation.

INTRODUCTION: Catheter ablation for paroxysmal AF (PAF) is limited by an unacceptable recurrence rate, mainly due to pulmonary vein (PV) reconnection. Strategies to minimize reconnection include adenosine infusion and also a waiting period of 30 minutes after PV isolation. The aim of the present study was to assess whether these two strategies revealed the same conduction gap. METHODS AND RESULTS: In total, 88 consecutive patients (54 males, mean age of 60 years) with drug refractory PAF underwent circumferential PV isolation (CPVI). After isolation of ipsilateral PVs, with entry and exit block checked using a circular mapping catheter, 20 mg ATP was injected during isoproterenol infusion to reveal dormant conduction gap(s). Unless the reconnection revealed by ATP persisted, PVs were further remapped with the circular mapping catheter at 30 minutes postisolation. Totally, PV reconnection was observed in 56 (64%) patients. 24.3% veins (80/329) were found reconnected. Reassessment at 30 minutes postablation was more efficient as compared to ATP induction (19.8% vs 14.6% for ATP). The agreement between these 2 methods is moderate (kappa value = 0.50). In veins that transiently reconnected after ATP administration and later observed at 30 minutes postablation, 94% (17 of 19) of them were found being reconnected with the same gap. CONCLUSION: Acute PV reconnection is common, occurring in 64% of patients, as detected by adenosine infusion and waiting time. Each shows a unique quality as compared to one another. The combined use of these 2 methods may reduce the AF recurrence rate after CPVI.

Optimal time for mesenchymal stem cell transplantation in rats with myocardial infarction.

BACKGROUND: Bone marrow mesenchymal stem cell (MSC) transplantation is a promising strategy in the treatment of myocardial infarction (MI). However, the time for transplanting cells remains controversial. The aim of this study was to find an optimal time point for cell transplantation. METHODS: MSCs were isolated and cultured from Sprague-Dawley (SD) rats. MI model was set up in SD rats by permanent ligation of left anterior descending coronary artery. MSCs were directly injected into the infarct border zone at 1 h, 1 week and 2 weeks after MI, respectively. Sham-operated and MI control groups received equal volume of phosphate buffered saline (PBS). At 4 weeks after MI, cardiac function was assessed by echocardiography; vessel density was analyzed on hematoxylin-eosin stained slides by light microscopy; the apoptosis of cardiomyocytes was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay; the expressions of proteins were analyzed by Western blot. RESULTS: MSC transplantation improved cardiac function, reduced the apoptosis of cardiomyocytes and increased vessel density. These benefits were more obvious in 1-week group than in 1-h and 2-week groups. There are more obvious increases in the ratio of bcl-2/bax and the expression of vascular endothelial growth factor (VEGF) and more obvious decreases in the expression of cleaved-caspase-3 in 1-week group than those in other two groups. CONCLUSION: MSC transplantation was beneficial for the recovery of cardiac function. MSC transplantation at 1 week post-MI exerted the best effects on increases of cardiac function, anti-apoptosis and angiogenesis.

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance.

OBJECTIVE: To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein (PV) ostia for patients with refractory paroxysmal atrial fibrillation (AF) under multi-slice spiral computed tomography (MSCT) guidance before the procedure. METHODS: A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation of PV ostia. The 36 male and 22 female patients with mean age of (57.4+/-9.5) (32-79) years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimensional image of the left atrium (LA) and proximal PVs. Patients then underwent segmental radiofrequency ablation of PV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. RESULTS: No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was (17.1+/-9.3) months. Forty-one patients (95%) experienced improved quality of life one month after the procedure. Thirty-six patients (83%) showed stable sinus rhythm, while 10 patients (23%) required additional anti-arrhythmic drugs. AF returned> or =1 time in 6 (14%) patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. CONCLUSION: It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.

Validation of the use of foreign gas rebreathing method for non-invasive determination of cardiac output in heart disease patients.

OBJECTIVE: To compare a new device (Innocor) for non-invasive measurement of cardiac output (CO) by foreign gas rebreathing method with conventional techniques used in the measurements of cardiac function. METHODS: Cardiac outputs measured by Innocor (CO(RB)) were compared with CO obtained by echocardiography (CO(EC)), Swan-Ganz thermodilution (CO(TD)), and left ventricle radiography (CO(LVR)) in 34 patients subjected to cardiac catheterization. Values obtained from the four methods were analyzed by linear regression and paired values were compared by the method of Bland and Altman in SPSS. RESULTS: There was strong positive correlation (r=0.94) between Innocor cardiac output values and the corresponding values obtained by thermodilution and between CO(EC) and CO(LVR) values. Thermodilution appears to overestimate cardiac output when compared to the values obtained with Innocor by (0.66+/-0.22) L/min (P<0.0001). There was no correlation between data obtained by Innocor and the corresponding CO(EC) and CO(LVR) values. CONCLUSION: Innocor CO(RB) is an easy, safe and well established method for non-invasive measurement of cardiac output with good prospects for clinical application in heart disease patients.