AF Group Research Articles

Effects of Task-Specific Augmented Feedback on Deficit Modification During Performance of the Tuck-Jump Exercise

Anterior cruciate ligament (ACL) injuries are prevalent in female athletes. Specific factors have possible links to increasing a female athlete's chances of suffering an ACL injury. However, it is unclear if augmented feedback may be able to decrease possible risk factors. To compare the effects of task-specific feedback on a repeated tuck-jump maneuver. Double-blind randomized controlled trial. Sports-medicine biodynamics center. 37 female subjects (14.7 ± 1.5 y, 160.9 ± 6.8 cm, 54.5 ± 7.2 kg). All athletes received standard off-season training consisting of strength training, plyometrics, and conditioning. They were also videotaped during each session while running on a treadmill at a standardized speed (8 miles/h) and while performing a repeated tuck-jump maneuver for 10 s. The augmented feedback group (AF) received feedback on deficiencies present in a 10-s tuck jump, while the control group (CTRL) received feedback on 10-s treadmill running. Outcome measurements of tuck-jump deficits were scored by a blinded rater to determine the effects of group (CTRL vs AF) and time (pre- vs posttesting) on changes in measured deficits. A significant interaction of time by group was noted with the task-specific feedback training (P = .03). The AF group reduced deficits measured during the tuck-jump assessment by 23.6%, while the CTRL training reduced deficits by 10.6%. The results of the current study indicate that task-specific feedback is effective for reducing biomechanical risk factors associated with ACL injury. The data also indicate that specific components of the tuck-jump assessment are potentially more modifiable than others.

Abstract 9121: Does AF Burden Measured By Implantable Loop Recorder During Post-ablation Blanking Period Predict Response At 12 Month Follow-up?

Introduction: The aim of this study was to identify if there is a threshold of AF burden during the first months post-ablation obtained through continuous subcutaneous monitoring that can identify patients at risk of subsequent AF recurrences. Methods: 613 patients with symptomatic drug refractory AF (17% with persistent AF) were enrolled in this retrospective analysis. All patients underwent circumferential pulmunary vein isolation (PVI) and were implanted with an ILR for collecting data on AF burden during 12-month follow-up. AF freedom (Responders) was defined as AF%<0.5% during follow-up period. A ROC curve analysis was performed to identify the value of AF burden during the first 2 months post ablation (Blanking Period, BP) that was predictive of late recurrence of AF. Results: After the first ablation procedure, 396 (65%) of the 613 patients were AF-free at 12-month: 346 out of 508 (68%) in the paroxysmal AF group and 50 out of 105 (47%) in the persistent AF group. Using the ROC curve (Fig 1), the specificity corresponding to 90% sensitivity was 75%. The corresponding threshold in the AF burden during the blanking period able to identify patients at risk of late recurrences was 7.1%, corresponding to 102h (= 4.25 days) in AF during the 2 months BP. At the multivariate analysis, a threshold in the AF burden <7.1% during BP was still highly significant (p<0.0001) and the odds of responders/non-responders was 21.5 (10.8 - 42.9). Conclusions: The BP AF pattern predicted response to catheter ablation. An AF burden ≥7.1% assessed by continuous monitoring was a powerful predictor of subsequent AF recurrence after initial ablation, and thus be an appropriate guide for early re-intervention.

Prediction of atrial fibrillation after ischemic stroke using P-wave signal averaged electrocardiography

BackgroundAtrial fibrillation (AF) is highly prevalent in patients with ischemic stroke, but the diagnosis is often difficult. MethodsThis study consisted of 68 stroke patients in sinus rhythm without history of AF. All patients underwent P-wave signal-averaged electrocardiography (P-SAECG), echocardiography, 24-h Holter monitoring, and measurement of plasma B-type natriuretic peptide (BNP) concentrations at admission. ResultsAn abnormal P-SAECG was found in 34 of 68 stroke patients. In the follow-up period of 11±4 months, AF developed in 17 patients (AF group). The remaining 51 patients were classified as the non-AF group. The prevalence of atrial late potentials (ALP) on P-SAECG, and the number of premature atrial contractions (PACs) were significantly higher in the AF group than those in the non-AF group (88.2% vs 37.3%; p<0.001, 149±120 vs 79±69; p=0.030, respectively). However, there were no significant differences in age, left atrial dimension, or BNP concentrations between both groups. Cox proportional hazards analysis revealed that the presence of ALP (risk ratio 11.15; p=0.002) and frequent PACs (more than 100/24h) (risk ratio 4.53; p=0.007) had significant correlation to the occurrence of AF. ConclusionsALP may be a novel predictor of AF in stroke patients. P-SAECG should be considered in stroke of undetermined etiology.

Estradiol supports in vitro development of bovine early antral follicles

Antrum formation and estradiol (E(2)) secretion are specific features of oocyte and granulosa cell complexes (OGCs). This study investigates the effect of E(2) on the in vitro development of bovine OGCs derived from early antral follicles as well as on the expression of genes in granulosa cells (GCs). The supplementation of culture medium with either E(2) or androstenedione (A(4)) improved the in vitro development of OGCs and the nuclear maturation of enclosed oocytes. When OGCs were cultured in medium containing A(4), developmentally competent OGCs secreted more E(2) than OGCs that were not competent. In addition, fulvestrant inhibited the effect of both E(2) and A(4) on OGCs development. Comprehensive gene expression analysis using next-generation sequence technology was conducted for the following three types of GCs: i) GCs of OGCs cultured for 4 days with E(2) (1 μg/ml; E(2)(+)), ii) GCs of OGCs cultured for 4 days without E(2) (E(2)(-)) or iii) OGCs that formed clear antrum after 8 days of in vitro culture in medium containing E(2) (1 μg/ml; AF group). GCs of the E(2)(+) group had a similar gene expression profile to the profile reported previously for the in vivo development of large follicles. This genetic profile included factors implicated in the up-regulation of E(2) biosynthesis and down-regulation of cytoskeleton and extracellular matrices. In addition, a novel gene expression profile was found in the AF group. In conclusion, E(2) impacts the gene expression profile of GCs to support the in vitro development of OGCs.

THE TIME-DEPENDENT STUDY ON CONNECTIVE TISSUE GROWTH FACTOR AND NERVE REMODELLING IN ATRIAL FIBRILLATION

ObjectivesTo dynamically observe the mechanism of connective tissue growth factor and nerve remodelling in the atrial fibrillation rabbit models.Methods(1) Ninety-six rabbits were randomly divided into two groups: control group (n=48)...

PREVALENCE AND RELATED FACTORS OF ARRHYTHMIAS IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

ObjectivesWe aim to explore the incidence and risk factors of AF, dangerous ventricular arrhythmias and bradyarrhythmia in patients with HCM, and improve the awareness of clinicians on hypertrophic cardiomyopathy (HCM)...

ELECTRICAL CHARACTERISTICS OF RAA AND LAA IN 48 H AF CANINE WITH MEA CHIP TECHNIQUE

ObjectivesTo explore electrical characteristics of RAA and LAA in 48 h AF canine with MEA chip technique.MethodsTwelve adult healthy mongrel canine were randomly divided into two groups:pacing group and control...

Impact of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mechanical mitral valve replacement for rheumatic mitral valve disease

The prognostic significance of preoperative atrial fibrillation on mitral valve replacement remains unclear. The aim of this study was to explore the effects of the presence of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mitral valve replacement for rheumatic valve disease. A retrospective analysis was performed on a total of 793 patients who underwent mitral valve replacement with or without tricuspid valve repair in our hospital. The patients selected were divided into two groups according to preoperative rhythm status. Patients with preoperative atrial fibrillation were assigned to the AF group, while patients in preoperative sinus rhythm were assigned to the SR group. Postoperative follow-up was performed by outpatient visits, as well as by telephone and written correspondence. Data gathered included survivorship, postoperative complications, left ventricular function and tricuspid regurgitation. For patients with atrial fibrillation vs those in sinus rhythm, there was no difference in postoperative mortality and morbidity. Follow-up was a mean of 8.6 ± 2.4 years. For patients with preoperative atrial fibrillation, 10-year survival from a Kaplan-Meier curve was 88.7%, compared with 96.6% in patients with preoperative sinus rhythm (P = 0.002). Multivariate analysis identified low left ventricular ejection fraction, older age, large left atrium and preoperative atrial fibrillation as significant adverse predictors for overall survival. Freedom from thromboembolism complications at 13 years was lower for patients with preoperative atrial fibrillation without maze procedure and left atrial appendage ligation, compared with that for patients with preoperative sinus rhythm without maze procedure and left atrial appendage ligation, and patients with concomitant maze procedure and left atrial appendage ligation (76.3 vs 94.8 vs 94.0%, respectively; P = 0.001). On echocardiography, the proportion of patients with significant tricuspid regurgitation was 38.7% (atrial fibrillation patients) vs 25.4% (patients in sinus rhythm; P < 0.001). Left ventricular ejection fraction measured 5 years after surgery increased by an average of 1.2% in the AF group, while it increased by 5.3% in the SR group (P = 0.028). Preoperative atrial fibrillation is a risk factor for long-term mortality, thromboembolism complications and tricuspid regurgitation, and it also has an adverse effect on the degree of improvement when considering left ventricular function.

Documentation of impaired coronary blood flow by TIMI frame count method in patients with atrial fibrillation

BackgroundAtrial fibrillation (AF) is associated with impaired coronary flow and diminished myocardial perfusion. In the present study we aimed to evaluate coronary blood flow by means of Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) in patients with AF in the absence of obstructive coronary artery disease (CAD). MethodsThis prospective study initially enrolled 166 patients with AF and 332 age- and gender-matched control subjects without AF. After diagnostic coronary angiography, TFC was assessed in the participants without obstructive CAD, with 146 in the AF group and 150 in the control group. ResultsThe TFC for three major coronary arteries and the mean TFC were found to be significantly higher in AF patients compared to control subjects (34.1±10.4 vs. 25.0±10.4, 31.8±9.7 vs. 23.7±9.1, and 32.3±9.5 vs. 24.1±8.4 for each artery and 32.8±9.2 vs. 24.3±8.9 for mean TFC, p<0.001 for all comparisons). The mean TFC was 28.8±7.9 in patients with paroxysmal AF, 33.7±8.7 in those with persistent AF, and 39.0±8.8 in those with long-standing or permanent AF (p<0.01 for all comparisons). After multivariate analysis, we found that the presence of AF remains to be independently associated with mean TFC. In AF group, baseline heart rate, left ventricular ejection fraction, AF duration and left atrium diameter were found to be independently associated with mean TFC. ConclusionsPatients with atrial fibrillation in the absence of obstructive coronary artery disease have significantly higher TIMI frame counts for all three coronary vessels, indicating impaired coronary blood flow, compared to the control subjects without atrial fibrillation.

The occurrence of atrial fi brillation in former top-level handball players above the age of 50

Objective Cardiac adaptation to sports activity in endurance athletes is considerably diff erent from that in power athletes. The eff ects of a highlevel team sport like handball, one of the most popular sports in the world, performed at a younger age, on cardiac rhythm in individuals above the age of 50 have not been investigated to date.Methods Thirty-three former top-level handball players from the fi rst German league (6 former world champions and numerous Olympians) (57.5 ± 5.5 y) joined our screening programme for former athletes and underwent electrocardiography, echocardiography and spiroergometry. Data were compared to 24 sedentary healthy controls.Results Ten of the 33 athletes suff ered from atrial fi brillation (AF). Left ventricular diameter was 53.68 ± 4.88 mm in the athletes group and 50.58 ± 4.12 mm in the healthy controls. Analysing the subgroups of handball players (‘AF group’ and ‘non-AF group’), spiroergometry showed oxygen consumption at the anaerobic threshold of 27.54 ± 6.77 ml/kg/min in the AF group and 31.24 ± 10.33 ml/kg/min in the non-AF group (P = 0.228). Absolute left atrial diameter was 44.34 ± 4.41 mm in the AF group (non-AF group 38.94 ± 3.77 mm, P< 0.001) (healthy controls 37.54 ± 4.34 mm, compared with all athletes P= 0.015). In all individuals left ventricular wall thickness was within normal limits. However, myocardial walls were thicker in the AF group (11.28 ± 1.83 mm) than in the non-AF group (9.44 ± 1.26 mm, P= 0.002). Athletes in the AF group (187.6 ± 6.42 cm) were signifi cantly taller than in the non-AF group (180.91 ± 7.31 cm, P= 0.018).Conclusion Not only endurance training, but also sports activity with a relevant static component, like team handball, might predispose for AF above the age of 50. LA size, height and myocardial wall thickness seem to aff ect the risk of developing AF. More data in non-endurance sports are mandatory to confi rm this hypothesis.

EP News: Basic and Translational

Igarashi et al (Circulation 2012;125:216, PMID 22158756) randomized 30 Yorkshire swines into 2 groups (sinus rhythm and atrial fibrillation [AF]) and each group into 3 subgroups: sham-operated control, gene therapy with adenovirus expressing connexin 40 (Cx40), and gene therapy with adenovirus expressing Cx43. Sinus rhythm animals had strong transgene expression, but no atrial conduction changes. In animals with AF, controls had reduced and lateralized Cx43 expression, and Cx43 gene transfer restored expression and cellular location to sinus rhythm control levels. In the AF group, both Cx40 and Cx43 gene transfer improved conduction and reduced AF relative to controls. The authors conclude that connexin gene therapy preserved atrial conduction and prevented AF.

Silencing gene of TLR4 down-regulates the effect of TLR2 signal transduction in RAW264.7 cells to anti-Aspergillus fumigatus conidia stimulation

Objective To study the role of TLR2 and TLR4 signal transduction in RAW264.7 monocyte-macrophages stimulated by Aspergillus fumigatus conidia,and to investigate the expression of TLR2 signal transduction after silencing gene of TLR4.Methods Macrophages were randomly divided into normal group ( N group),normal+stimulated with Aspergillus fumigatus conidia ( N +Af group ),normal + transfected with TLR4-siRNA [ TLR4 (RNAi) group ],normal+transfected with TLR4-siRNA +stimulated with Aspergillus fumigatus conidia[ TLR4(RNAi) +Af group].RT-PCR and Western blot were used to assay expression levels of TLR2,TLR4,MyD88 mRNA and pro-inflammatory cytokines TNF-α protein when macrophages were stimulated 12 h by Aspergillus fumigatus conidia after tranfected 24 h with TLR4-siRNA by technology of RNAi.Results ( 1 ) Compared with N group,the expression of TLR2,TLR4,MyD88 mRNA and TNF-αprotein in N+Af group significantly increased before silencing gene of TLR4.(2) Silencing efficiency of macrophates was up to 83％ after transfected with TLR4-siRNA.(3)The expression of TLR2,MyD88 mRNA in TLR4 (RNAi) group significantly decreased contrast with normal group.Meanwhile the expression of TLR2,MyD88 mRNA and TNF-α protein also obviously reduced in TLR4(RNAi) +Af group when compared with N +Af group.Compared with TLR4 (RNAi) group,the expression of MyD88 mRNA in TLR4 (RNAi) +Af group significantly increased.However,the expression of TLR2 mRNA and TNF-α protein have no significant change after silencing gene of TLR4.Conclusion Signaling pathway of TLR2 and TLR4 in macrophages was activated by given stimulus of Aspergillusfumigatus conidia and exerted the effect of anti-Aspergillus fumigatus spores stimulation through the release of pro-inflammatory cytokines TNF-α.Meanwhile,silencing gene of TLR4 down-regulate the effect of TLR2 signal transduction in RAW264.7 cells to anti-Aspergillus fumigatus conidia stimulation,and it found that TLR4 played an more important role by contrast with TLR2. Key words: TLR2 ; TLR4 ; TLR4-siRNA ; Aspergillus fumigatus conidia; Regulation mechanism

Core-Needle Biopsy Is More Useful Than Repeat Fine-Needle Aspiration in Thyroid Nodules Read as Nondiagnostic or Atypia of Undetermined Significance by the Bethesda System for Reporting Thyroid Cytopathology

Thyroid nodules with fine-needle aspiration (FNA) readings of nondiagnostic or atypia of undetermined significance (AUS), also referred to as follicular lesion of undetermined significance (FLUS) are problematic for their optimal management. The usefulness of performing a core-needle biopsy (CNB) to clarify whether these nodules are benign or malignant has not been established. The purpose of the present study was to determine whether CNB provides better diagnostic information than repeat FNA (rFNA) in thyroid nodules having nondiagnostic or AUS/FLUS readings. The Bethesda System for Reporting Thyroid Cytopathology was used for FNA readings and for CNB readings. The study included 225 thyroid nodules from 220 consecutive patients who previously had nondiagnostic (Group N-DIAG, n=64) or AUS/FLUS (Group AF, n=161) FNA readings. All patients simultaneously underwent rFNA and CNB of each nodule. The nondiagnostic and AUS/FLUS readings by rFNA and by CNB were compared. The diagnostic sensitivities of rFNA and CNB for malignancy in thyroid nodules were also assessed. Statistical analysis was performed using a McNemar's test. In N-DIAG Group, the nondiagnostic readings for the CNBs were lower than that those for rFNAs (1.6% vs. 28.1%, p<0.001). In the AF Group, the AUS/FLUS readings for the CNBs were lower than those for the rFNAs (23.6% vs. 39.8%, p<0.001). The inconclusive diagnoses (nondiagnostic or AUS/FLUS) for the CNBs were lower than those for the rFNAs in Group N-DIAG (12.5% vs. 45.3%, p<0.001) and Group AF (26.7% vs. 49.1%, p<0.001). The sensitivity of CNB for thyroid malignancy was higher than that of rFNA in Group N-DIAG (100% vs. 71.4%, p=0.125) and Group AF (78.5% vs. 55.4%, p<0.001). After patients have had one FNA of a thyroid nodule yielding inconclusive diagnostic results (nondiagnostic or AUS/FLUS), CNB is more useful than rFNA for reducing the frequency of inconclusive diagnostic results. CNB will improve the diagnostic performance for malignancy more than rFNA in thyroid nodules that on the first FNA had nondiagnostic or AUS/FLUS readings.

Abstract 18260: Local Interleukin-6 and Pericardial Drainage Volume are Associated with Atrial Fibrillation After Coronary Artery Bypass Grafting

Objective. To examine the relationship between IL-6, WBC, CRP levels and volume of pericardial drainage in patients with AF following CABG. Method. In 124 patients with sinus rhythm (SR) undergoing elective isolated CABG, IL-6, WBC count and CRP levels were measured in pericardial drainage and peripheral blood at six, 12, and 18 hours (hrs) postoperatively. The volume of pericardial drainage was also recorded at the same time interval. Two-factor ANOVA for repeated measures was used to test the trends of the above parameters and their relationship with postoperative AF (POAF). Results. AF occurred in 44 (35.5%) patients and IL-6 levels in pericardial drainage increased over time in this group (from 1353.9 pg/ml at six hours to 2189.2 pg/ml at 18 hrs), while it was peaked at 12 hrs and declined thereafter in the SR group (1541.5 pg/ml at six hours, 1906.3pg/ml at 12 hrs, and 1876.2 pg/ml at 18 hrs). Two-factor ANOVA for repeated measures showed that the change of mean IL-6 levels in drainage over time between the two groups was significantly different ( P = 0.016). The postoperative levels of IL-6 in peripheral blood declined slowly over 18 hours in both groups (from 71.61 pg/ml to 62.90 pg/ml and 85.56 pg/ml to 75.92 pg/ml, respectively). Interestingly, IL-6 levels in drainage were 28 and 22 times higher in drainage than those in blood in the AF and SR groups, while the difference of IL-6 levels in drainage and blood in the AF group was six times higher than in the SR group ( P = 0.014). Although the volume of drainage decreased over time in both groups, logistic regression showed that age adjusted total drainage of ≥ 430 ml during the first 18 hours post-op was an independent predictor of POAF (OR 3.91, 95%CI 1.55-10.27). CRP levels in the drainage of the AF and SR groups increased noticeably from 3.74 and 3.08 mg/L at six hours, to 16.76 and 15.45 mg/L at 18 hrs after surgery, and in blood from 9.95 and 9.82 mg/L to 41.70 and 41.36 mg/L, respectively. CRP levels in blood were higher than in drainage for both groups ( P &lt; 0.001). There was no association between the occurrence of POAF and CRP levels or WBC in either drainage, or blood. Conclusion. IL-6 may be produced locally after CABG, and the levels of IL-6 in, as well as the volumes of pericardial drainage were associated with POAF.

Diuretics administration correlate with atrial fibrillation in patients with chronic systolic heart failure

BackgroundLittle is known about the prognostic value of diuretics for AF in patients with chronic systolic heart failure (CSHF).Methods16681 patients, diagnosed with CSHF, from 12 hospitals were analysed. Patients were...

532 Postoperative atrial fibrillation increases long-term mortality in older patients undergoing CABG surgery

532 Postoperative atrial fibrillation increases long-term mortality in older patients undergoing CABG surgery

A novel radiofrequency ablation catheter using contact force sensing: Toccata study

The aim of this multicenter study was to evaluate the device- and procedure-related safety of a novel force-sensing radiofrequency (RF) ablation catheter capable of measuring the real-time contact force (CF) and to present CF data and its possible implications on patient safety. The clinical outcome of RF ablation for the treatment of cardiac arrhythmias may be affected by the CF between the catheter tip and the tissue. Insufficient CF may result in an ineffective lesion, whereas excessive CF may result in complications. Seventy-seven patients (43 with right-sided supraventricular tachycardia [SVT] and 34 with atrial fibrillation [AF]) received percutaneous ablation with the novel studied catheter. The CF applied and safety events related to the procedure were reported. CF values at mapping ranged from 8 ± 8 to 60 ± 35 g and from 12 ± 10 to 39 ± 29 g in the SVT group and the LA group, respectively, showing a significant interinvestigator variability (P < .0001). High transient CFs (>100 g) were noted in 27 patients (79%) of the LA group. One device-related complication (tamponade, 3%) occurred in the AF group. Catheter ablation using real-time CF technology is safe for the treatment of SVT and AF. High CFs may occur during catheter manipulation and not just during ablation, suggesting that measuring CF may provide additional useful information to the operator for safe catheter manipulation. In the future, CF-sensing catheters may also increase the effectiveness of RF ablations by allowing better control of the RF lesion size.

A Comparison of Articaine and Fentanyl-Supplemented Articaine for Hemodialysis Fistula Creation under Ultrasound-Guided Axillary Block

The aim of this prospective randomized, double-blinded study was to evaluate the effect of fentanyl addition to articaine on the duration of sensory as well as motor blocks, and the duration of analgesia during hemodialysis fistula creation under ultrasound-guided axillary block. Fifty patients were randomly allocated to two groups, an articaine group (A), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL of isotonic sodium chloride solution, and an articaine-fentanyl group (AF), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL (100 µg) of fentanyl. The onset as well as the duration of sensory and motor blocks, the time necessary for first analgesic administration, the hemodynamic parameters, and the side effects were recorded. Three patients in Group A and two patients in Group AF due to incomplete block were excluded from the study. The duration of sensory and motor blocks was significantly longer in the AF group than in the A group. The first time for analgesic need was also significantly longer in group AF (363 ± 134 min) than in group A (244 ± 84 min) (p = 0.001). The addition of fentanyl did not improve the onset of sensory and motor block times. Hemodynamic parameters were similar in the two groups. In conclusion, the addition of fentanyl to articaine in axillary block prolongs the duration of sensory and motor blocks, as well as the time of first analgesic requirement.

Plasma Connective Tissue Growth Factor (CTGF) Would Be a Novel Potential Biomarker of Atrial Structural Remodeling in Patients with Atrial Fibrillation

Purpose: We hypothesized plasma CTGF concentration would be a biomarker for clinical AF. Methods: The study population consisted of consecutive 64 patients with minimal structural heart disease. They were divided into two groups; 1) SR (sinus rhythm, n=6), and 2) AF (n=58, chronic AF n=13, and paroxysmal AF n=45). The AF group was further divided into two subgroups with and without ARB or angiotensin converting enzyme inhibitor (ACEI). The clinical characteristics and plasma CTGF concentrations, which were evaluated by ELISA, were compared. Results: The plasma CTGF concentration in total population was 0.653±0.091 ng/mL and tended to be higher in AF group than SR group (SR vs. AF groups: 0.450±0.091 vs. 0.674±0.101 ng/mL, p=0.328). ARB/ACEI was administered in 33/58 AF patients (56.9%). Plasma CTGF concentration tended to be lower in the AF with ARB/ACE-I group than the AF without ARB/ACE-I group (AF+ARB/ACEI vs. AF-ARB/ACEI groups: 0.583±0.083 vs. 0.794±0.206 ng/mL, p=0.198). Conclusions: It might be speculated plasma CTGF concentration would be a novel biomarker for AF and this increase would be suppressed by ARB/ACEI in clinical patients with AF.

Connexin Gene Transfer Preserves Conduction Velocity and Prevents Atrial Fibrillation

Introduction: Fibrosis, cellular dysfunction and gap junction protein alterations occur in AF and cause conduction delay. We performed this study to test the hypothesis that gap junction protein overexpression would improve conduction and prevent AF. Methods and Results: Thirty Yorkshire swine were randomized into sinus rhythm (SR) and AF groups (n=15 per group). Each group included 3 subgroups: sham-operated control, gene therapy with adenovirus expressing connexin (Cx) 40 and Cx43, with 5 animals in each subgroup. All animals had epicardial gene painting; the AF group had burst atrial pacing. All animals underwent terminal study 7 days after gene transfer. SR animals had strong transgene expression but no atrial conduction changes. In AF animals, controls had reduced and lateralized Cx43 expression, and Cx43 gene transfer restored the expression of total and phosphorylated Cx43 to SR control levels. Immunohistochemical analysis revealed connexin localization to the intercalated disk after gene transfer. In the AF group, both Cx40 and Cx43 gene transfer improved conduction and reduced AF relative to controls. Conclusions: Atrial-specific gene therapy with gap junction protein preserved atrial conduction velocity and prevented AF.