[Clinical characteristics and genetic analysis of three pediatric patients with idiopathic restrictive cardiomyopathy].

OBJECTIVE: Restrictive cardiomyopathy (RCM) is rare in children, and little is known about the molecular basis of RCM. The aim of this study was to investigate the clinical and myopathological characteristics and to detect mutations on cardiac sarcomere protein genes in three idiopathic pediatric RCMs. METHODS: Detailed clinical characteristics and familiar history were obtained in three idiopathic pediatric RCMs. One hundred healthy pediatric individuals were recruited as controls. Histological evaluation was performed with heart tissue retrieved at catheterization in case-1 and case-2. The entire coding sequences of four cardiac sarcomere protein genes, including cardiac troponin T (TNNT2), cardiac troponin I(TNNI3), ß-myosin heavy chain (MYH7), and α-actin (ACTC)were screened for mutations. Sequence variants were then tested in the family as well as in 100 healthy control DNAs. RESULTS: All three index cases were diagnosed as primary RCMs without family history, and their clinical conditions deteriorated rapidly. Case-1 was in combination with ventricular septal defect. Case-2 was in combination with mid- and inferoseptal hypertrophy. In case-1, myocardial biopsies displayed extensive an isomorphism and disarray of cardiomyocytes; electron microscopy showed large stacks of severely dysmorphic megamitochondria and focal Z-disc streaming. In case-2, endomyocardial biopsy revealed moderate myocyte hypertrophy with mild interstitial fibrosis; transmission electron microscopy showed misalignment of Z-bands and unequal Z-Z band distances. Genetic analysis identified two heterozygous missense mutations in TNNI3, with R204H in case-1 and R192H in case-3 respectively. A de novo heterozygous deletion in TNNT2 (p. Asn100_Glu101del) was identified in case-2. Sequence analysis shows that all three mutations are located in a position highly conserved across many species. The three mutations were negative for their parents and controls. CONCLUSION: The clinical conditions in all three index cases are deteriorated rapidly after diagnosed as primary RCM. Three heterozygous mutations including two in TNNI3 and one in TNNT2 gene are identified in the three RCMs respectively, which are considered as causative mutations. These findings provide new insights into the molecular etiology responsible for pediatric RCM.

[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.

[Initial experience of percutaneous coronary intervention guided by computed tomography coronary angiography derived roadmap and magnetic navigation system].

OBJECTIVE: To evaluate the feasibility, efficacy and safety of the percutaneous coronary intervention (PCI)guided by computed tomography (CT) coronary angiography derived roadmap and magnetic navigation system (MNS). METHODS: During June 2011 and May 2012, thirty consecutive patients receiving elective PCI were enrolled, coronary artery disease was primarily diagnosed by dual-source CT coronary angiography (DSCT-CA) at outpatient clinic and successively proved by coronary artery angiography in the hospital. Target vessels from pre-procedure DSCT-CA were transferred to the magnetic navigation system, and consequently edited, reconstructed, and projected onto the live fluoroscopic screen as roadmap. Parameters including characters of the target lesions, time, contrast volume, radiation dosage for guidewire crossing, and complications of the procedure were recorded. RESULTS: Thirty patients with 36 lesions were recruited and intervened by PCI. Among the target lesions, sixteen were classified as type A, 11 as type B1, 8 as type B2, 1 as type C. The average length of the target lesions was (22.0 ± 9.8) mm, and the average stenosis of the target lesions was (81.3 ± 10.3)%. Under the guidance of CT roadmap and MNS, 36 target lesions were crossed by the magnetic guidewires, with a lesion crossing ratio of 100%. The time of placement of the magnetic guidewires was 92.5 (56.6 - 131.3) seconds. The contrast volume and the radiation dosage for guidewire placement were 0.0 (0.0 - 3.0) ml and 235.0 (123.5 - 395.1) µGym(2)/36.5 (21.3 - 67.8) mGy, respectively. Guidewires were successfully placed in 21 (58.3%) lesions without contrast agent. All enrolled vessels were successfully treated, and there were no MNS associated complications. CONCLUSIONS: It is feasible, effective and safe to initiate PCI under the guidance of CT derived roadmap and MNS. This method might be helpful for the guidewire placement in the treatment of total occlusions.

Overexpression of FABP3 promotes apoptosis through inducing mitochondrial impairment in embryonic cancer cells.

Fatty acid-binding protein 3 (FABP3) is a low-molecular-weight protein with a distinct tissue distribution that may play an important role in fatty acid transport, cell growth, cellular signaling, and gene transcription. Previously, we have found that FABP3 was involved in apoptosis-associated congenital cardiac malformations, but the underlying mechanisms have not yet been described. In the present study, we investigated the characteristics of mitochondrial dysfunction in embryonic cancer cells (P19 cells) that overexpressed FABP3. We demonstrated that in FABP3-overexpressing P19 cells a lower cellular ATP production was accompanied by a dramatic decrease in mitochondrial membrane potential (MMP), despite the lack of a substantial decrease in the mtDNA copy number. In addition, FABP3 overexpression also led to an imbalance in mitochondrial dynamics and to excess intracellular reactive oxygen species production. Collectively, our results indicated that overexpression of FABP3 in P19 cells caused mitochondrion dysfunction that might be responsible for the development of FABP3-induced apoptosis.

Downregulation of quinone reductase 2 attenuates vascular smooth muscle cells proliferation and neointimal formation in balloon injured rat carotid artery.

BACKGROUND/AIMS: Quinone reductase 2 (NQO2) is a flavoprotein that catalyzes the metabolic reduction of quinines, but its biological mechanism in vascular smooth muscle cells (VSMCs) is unclear. The aim of this study was to evaluate the role of NQO2 on VSMCs proliferation and the neointimal formation in balloon injured rat carotid artery. METHODS: Left common carotid arteries from Sprague-Dawley rats were injured by a balloon catheter, and the injured arteries were incubated with 50 µL solution of NQO2-siRNA-GFP lentiviral vectors, NC-siRNA-GFP lentiviral vectors or PBS for 1 h. The rats were euthanized for morphometric and immunohistochemical analysis, real-time PCR and western blot analysis at 2 weeks after balloon injury and gene transfer. The cultured rat VSMCs transduced with NQO2-siRNA-GFP or NC-siRNA-GFP lentiviral vectors were used for cell proliferation assay, real-time PCR and western blot analysis. In order to detect the vascular or intracellular ROS level, the lentiviral vectors without GFP were used to transfect the injured common carotid arteries and the cultured rat VSMCs. RESULTS: Lentiviral vectors bearing NQO2 siRNA could reduce NQO2 protein level and suppress NQO2 mRNA expression in balloon injured artery walls and cultured rat VSMCs. Downregulation of NQO2 significantly suppressed VSMCs proliferation and intimal formation. NQO2 siRNA treatment could reduce vascular or intracellular ROS level and decrease the phosphorylation of the ERK1/2 in balloon injured artery walls and cultured rat VSMCs. CONCLUSION: Our study suggests that downregulation of NQO2 significantly suppresses VSMCs proliferation and progression of neointimal formation after vascular injury.

Renin-angiotensin-aldosterone system gene polymorphisms and coronary artery disease: detection of gene-gene and gene-environment interactions.

OBJECTIVE: The objective of this study was to explore the association between coronary artery disease and genetic polymorphisms of the renin-angiotensin-aldosterone system (RAAS) pathway. In addition, we examined the interactions between demographic and lifestyle risk factors (environmental factors including age, sex, smoking status, alcohol intake) and RAAS polymorphisms on disease risk. METHODS: A total of 1089 subjects who underwent coronary angiography were enrolled in this study. Eight RAAS polymorphisms were genotyped in this population: the G2350A (rs4343) polymorphism in exon 17 of the angiotensin converting enzyme (ACE) gene, 1166A→C (rs5186) and 573C/T (rs5182) in the angiotensin II type 1 receptor (AGTR1) gene, the -344C→T transversion (rs1799998) in the aldosterone synthase (CYP11B2) gene, and the G-217A (rs5049), G-6A (rs5051), M235T (rs699; T4072C), and T174M (rs4762; C3889T) polymorphisms in the angiotensinogen (AGT) gene. Subjects with coronary heart disease were defined as those with at least 50% stenosis in at least one major coronary artery, and, the severity of coronary atherosclerosis was defined by the Gensini scoring system. RESULTS: Compared to the subjects with AA genotype, the subjects with AG + GG genotype of rs1799998 had significant lower gensini score (p=0.029). After adjusting for age, gender, cigarette smoking, and alcohol intake status, the AG genotype (OR 0.717 95%CI 0.541-0.950, p=0.021) and the AG + GG genotype (OR 0.730 95%CI 0.559-0.954, p=0.021) distributions of rs1799998 were significantly different between the cases and controls compare to the AA genotype. Subjects with three at-risk loci had increased risk of coronary artery disease compared to subjects carrying 0 or 1 risk-associated polymorphism (OR [95% CI]:1.579 [1.077-2.316], p=0. 019), and the significance of the association was not reduced after adjusting for age, sex, cigarette smoking, or alcohol intake (adjusted OR [95% CI]: 1.673 [1.116-2.507], p=0.013). The results of multifactor-dimensionality reduction analysis revealed an interaction effect of CYP11B2 -344C→T, age, and smoking status on the risk of coronary heart disease (training OR [95% CI]: 3.7685 [2.8463-4.9895], p<0.0001; testing OR [95% CI]: 2.7583 [1.2038-6.3203], p=0.015). CONCLUSIONS: Subjects who carried the G allele of the rs1799998 polymorphism significantly associated with coronary heart disease and severity of coronary atherosclerosis estimated by the Gensini score in the whole population of the study. And, multiple RAAS gene polymorphisms are associated with coronary artery disease. The interaction of the CYP11B2 -344C→T polymorphism (rs1799998), age, and smoking status is also associated with enhanced risk of coronary artery disease.

Expressing murine p56Hck(ca) promotes HeLa cells' motility and invasion via triggering redistribution of F-actin and microtubules.

Hck is the unique example among the Src PTKs to be expressed as two isoforms, which are generated by alternative translation. The two isoforms differs from each other by a 21 N-terminal amino acids sequence which supports myristoylation. Though it has been shown that these different acylation states govern the different subcellular localization of the isoforms and each Hck isoform could play a specific role, little study focus on the function of p56Hck. To investigated the role of p56Hck isoform in cell migration, GFP targeted p56Hck plasmid and its constitutively active form were constructed and transiently transfected into HeLa cells, F-actin staining and Indirect immunofluorescence for microtubules were then performed. Phagokinetic track motility assay and In vitro invasion assays were also investigated after transiently transfection respectively. In this study, we found ectopically expressing a constitutively active form of 56Hck will lead to membrane protrusion and F-actin reorganization in HeLa cells. Both 56Hck and its constitutive active form will lead to redistribution of microtubules and enhancement of cell motility and cell invasion. Hck inhibitor PP2 supplementation eliminated cell motility and cell invasion of p56Hck while PP3, a negative control of PP2 didn't eliminate cell motility and cell invasion of p56Hck. It is indicated that enhanced cell motility and cell invasion in p56Hck ectopically expressed HeLa cells are the results of reorganization of F-actin and microtubules.

[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.

An algorithm to predict the site of origin of focal atrial tachycardia.

BACKGROUND: Only a few algorithms for predicting the site of origin of focal atrial tachycardia (AT) have been reported. We aimed to develop a new and more effective algorithm. METHODS: Surface 12-lead electrocardiograms were collected during tachycardia and sinus rhythm in 61 patients who received successful radiofrequency ablation. P-wave polarities, durations, and amplitudes were analyzed. Predictive values of the most significant parameters were determined. An algorithm was then developed and prospectively evaluated in 30 new consecutive AT patients. RESULTS: Thirty-six percent (22/61) of the foci were located at the ostium of coronary sinus (CS). Other common foci included pulmonary veins (PVs, n = 15), right atrial appendage (RAA, n = 7), parahisian area (n = 7), and crista terminalis (CT, n = 3). Positive P waves in inferior leads (II, III, and aVF) and a negative P wave in lead aVR indicated high atrial origins (high CT, superior PVs, and RAA, defined as Area A), with a sensitivity of 95% and a specificity of 90%. Negative P waves in inferior leads and a positive P wave in lead aVR suggested right low septal origins (CS ostium and inferior tricuspid annulus, defined as Area B), with good sensitivity and specificity (88% and 89%, respectively). This new P-wave diagnostic algorithm correctly identified the site of origin in 90% of AT cases. CONCLUSION: Combination of data from multiple leads and regrouping of sites of origin provides a better predictive value.

Negative association between free triiodothyronine level and international normalized ratio in euthyroid subjects with acute myocardial infarction.

AIM: To investigate the relationship between free triiodothyronine (FT3) and the international normalized ratio (the ratio of the prothrombin time of a patient to the normal sample, INR) in Chinese euthyroid subjects with acute ST-segment elevation myocardial infarction (STEMI). METHODS: A total of 231 consecutive patients (177 males, 54 females) with STEMI were enrolled. Anthropometric and laboratory measurements, including heart rate, respiratory rate, blood pressure, body temperature, platelet count, INR, prothrombin time, activated partial thromboplastin time, FT3, free thyroxine (FT4), and thyroid-stimulating hormone, were collected from all the patients. The levels of FT3 and FT4 were measured with a full-automatic immune analyzer. The INR was determined using a coagulation analyzer. RESULTS: Patients were classified into 4 groups according to their quartile FT3 and FT4 levels: 0.40-3.09 (n=52), 3.10-3.69 (n=56), 3.70-4.29 (n=64) and 4.30-7.10 (n=59) for FT3; 4.9-14.8 (n=57), 14.9-16.8 (n=58), 16.9-18.7 (n=57) and 18.8-29.0 (n=59) for FT4. Subjects with a high FT3 level had significantly lower values of INR than those with a low FT3 level (P=0.01). Multiple linear regression analysis revealed decreased serum FT3 as an independent risk factor for elevated INR values (ß=-0.139, P=0.025). The value of INR was similar among the 4 groups according to the quartile FT4 levels (P=0.36). CONCLUSION: Free triiodothyronine was negatively associated with INR in the patients with acute STEMI and normal thyroid function.

Severity of coronary atherosclerosis is an independent predictor of the left ventricular ejection fraction.

1. We studied the association between the level of the left ventricular ejection fraction and the severity of coronary atherosclerosis. 2. The study population consisted of 850 consecutive patients who underwent coronary angiography for suspected or known coronary atherosclerosis. Anthropometric measurements including the body mass index, blood pressure, blood lipids, blood glucose and leucocyte count were taken. The severity of coronary atherosclerosis was defined by the Gensini score. 3. When the level of the left ventricular ejection fraction was examined as a categorical variable classified by quartile values, subjects with a high left ventricular ejection fraction level had significantly lower Gensini scores than those with a low left ventricular ejection fraction level (P=0.000). Spearman's correlation analysis suggested that the left ventricular ejection fraction was significantly negatively associated with Gensini score (r= -0.213, P=0.000). Multiple stepwise linear regression analysis showed that the Gensini score was significantly independently associated with the left ventricular ejection fraction level (ß= -0.194, P=0.000). Furthermore, multivariable stepwise logistic regression analysis showed that the Gensini score was the independent risk factor for dysfunction of left ventricular ejection (OR=2.048, 95% CI=1.517-2.763). 4. The severity of coronary atherosclerosis was defined by the Gensini score. This was a strong and statistically highly significant predictor of the left ventricular ejection fraction level and dysfunction of left ventricular ejection independent of other major risk factors including age, body mass index, blood pressure, fasting blood glucose, blood lipid and leucocyte count.

[Activation of calcium-sensing receptors is associated with apoptosis in cardiomyocytes under simulated ischemia/reperfusion].

OBJECTIVE: To examine the association of activation of calcium-sensing receptors (CaSR) with apoptosis in cardiomyocytes under simulated ischemia/reperfusion. METHODS: Ventricular cardiomyocytes of neonatal rats were incubated in ischemia-mimetic solution for 2 h, then re-incubated in normal culture medium for 24 h to establish a model of simulated ischemia/reperfusion (I/R). Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL assay). The expression of CaSR mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR). The expression of Caspase -3 and Bcl-2 was detected by Western blotting. RESULT: The simulated I/R enhanced the expression of CaSR and cardiomyocyte apoptosis. GdCl(3), a specific activator of CaSR, further increased the expression of CaSR and cardiomyocyte apoptosis, along with upregulation of Caspase-3 and downregulation of Bcl-2. CONCLUSION: CaSR is associated with I/R injury and apoptosis in neonatal rat ventricular cardiomyocytes via suppressing Bcl-2 and promoting Caspase -3 expression.

[Impact of metoprolol use in the treatment of patients with electrical-storm after cardioverter defibrillators implantation].

OBJECTIVE: To explore the effectiveness of the metoprolol dosage adjustment on reducing the incidence of electrical-storm (ES) in patients with Implantable Cardioverter Defibrillators (ICDs). METHODS: Data from patients with ICD implantation between Jan, 2003 and Jun, 2006 in our hospital were retrospectively analyzed. ES was defined as either ≥ 3 times of ventricular tachyarrhythmias (VTAs) resulting in ICD therapy or VTAs lasting more than 30 s detected by ICD without any therapy within 24 hours. RESULTS: During a follow-up period of (27.5 ± 21.2) months, ES was recorded in 39 cases [34 males, average age (52.0 ± 13.1) years] out of 119 patients (32.8%) and 9 patients died after ES. During the period of storm attack, ES was successfully controlled in 25/30 patients by various interventions, including predisposing factors corrected in 5 cases, ICD reprogramming and antiarrhythmic drugs therapy optimized in 16 cases (one received intravenous injection of metoprolol), and VTAs eliminated by catheter ablation in 4 cases. ES was spontaneously resolved in the remaining 5 cases. In the chronic phase, 2 patients with Brugada syndrome were treated with Quinidine mono-therapy while the dosage of metoprolol was adjusted in the remaining 23 patients and the dosage of metoprolol was increased gradually from (26.8 ± 13.9) mg/d to (88.9 ± 53.5) mg/d without any adverse effects (9 patients received also oral amiodarone 200 mg/d). Post dosage adjustment, the total VTA episodes [(1.9 ± 1.7) times/month vs. (0.8 ± 0.6) times/month, P = 0.004], incidence of antitachycardia pacing therapies [(4.2 ± 3.8) runs/month vs. (2.3 ± 2.0) runs/month, P = 0.003], as well as electrical cardioversion or defibrillation [(1.1 ± 0.9) times/month vs. (0.4 ± 0.2) times/month, P = 0.001] were significantly decreased. ES was not controlled until a extremely high dosage [225 - 300 (255.3 ± 41.7) mg/d] of metoprolol was reached in the remaining 5 patients. CONCLUSIONS: Metoprolol use is essential and its dosage should be individualized in the majority of ICD recipients with ES. In approximately 1/6 patients, the dosage of metoprolol should be higher than 200 mg/d.

[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.

Inhibition of MAPK signaling by eNOS gene transfer improves ventricular remodeling after myocardial infarction through reduction of inflammation.

Endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) may play an important role in attenuating cardiac remodeling and apoptosis after myocardial infarction. However, the anti-inflammation effects of eNOS in infarcted myocardium and the role of MAPK signaling in eNOS/NO mediated cardiac remodeling have not yet been elucidated. Adenovirus carrying Human eNOS gene was delivered locally into heart 4 days prior to induction of myocardial infarction (MI) by left anterior descending coronary artery ligation. Monocyte/macrophage infiltration was detected by ED-1 immunohistochemistry. Western blot was employed to examine the activation of MAPK. eNOS gene transfer significantly reduced myocardial infarct size and improved cardiac contractility as well as left ventricle (LV) diastolic function at 7 days after MI. In addition, eNOS gene transfer decreased monocyte/macrophage infiltration in the infarct region of the heart. Phosphorylation of MAPK after MI were also dramatically reduced by eNOS gene transfer. All the protective effects of eNOS were blocked by N(ω)-nitro-L-arginine methyl ester (L-NAME) administration, indicating a NO-mediated event. These results demonstrate that the eNOS/NO system provides cardiac protection after MI injury through inhibition of inflammation and suppression of MAPK signaling.

Improvement of heart function in postinfarct heart failure swine models after hepatocyte growth factor gene transfer: comparison of low-, medium- and high-dose groups.

Despite advances in surgical and reperfusion therapy, there is no effective therapy currently exists to prevent the progressive decline in cardiac function following myocardial infarction. Hepatocyte growth factor has potent angiogenic and anti-apoptotic activities. The aim of this study was to investigate the therapeutic effect and dose-effect relationship on postinfarction heart failure with different doses of adenovirus-mediated human hepatocyte growth factor (Ad(5)-HGF) transference in swine models. Totally twenty swine were randomly divided into four groups: (a) control group (null- Ad(5), 1 ml); (b) low-dose group (1 x 10(9) Pfu/ml Ad(5)-HGF, 1 ml); (c) medium-dose group (5 x 10(9) Pfu/ml Ad(5)-HGF, 1 ml); (d) high-dose group (1 x 10(10) Pfu/ml Ad(5)-HGF, 1 ml). Four weeks after left anterior descending coronary artery (LAD) ligation, different doses of Ad(5)-HGF were transferred in three therapeutic groups via right coronary artery. Four and seven weeks after LAD ligation, gate cardiac perfusion imaging was performed to evaluate cardiac perfusion and left ventricular ejection fraction (LVEF). Seven weeks after surgery, the apoptotic index of cardiocyte was observed by TUNEL, the expression of Bcl-2, Bax, alpha-SMA and Factor VIII in the border zones were evaluated by immunohistochemistry, respectively. Four weeks after myocardial infarction, no significant difference was observed among four groups. Three weeks after Ad(5)-HGF transfer, the improvement of cardiac perfusion and LVEF was obviously observed, especially after 1 x 10(10) Pfu Ad(5)-HGF transfer. TUNEL assay showed that 5 x 10(9) Pfu and 1 x 10(10) Pfu Ad(5)-HGF treatment had a obvious reduction in the apoptotic index compared with the null-Ad(5) group, especially after 1 x 10(10) Pfu Ad(5)-HGF treatment. The expression of Bcl-2 protein was increased and the expression of Bax protein was inhibited in the 5 x 10(9) Pfu and 1 x 10(10) Pfu Ad(5)-HGF groups compared with the null-Ad(5) group. The vessel density of Factor VIII(+) and alpha-SMA(+) was increased in Ad(5)-HGF groups compared with the null-Ad(5) group. There were no significant differences in angiogenesis, reducing apoptosis and ameliorating heart function between the 1 x 10(9) Pfu Ad(5)-HGF group and the null-Ad(5) group. Although no statistical difference was observed between 1 x 10(10) Pfu and 5 x 10(9) Pfu Ad(5)-HGF groups, the cardiac protective effects of 1 x 10(10) Pfu Ad(5)-HGF treatment were greater than 5 x 10(9) Pfu Ad(5)-HGF treatment. Different doses of Ad5-HGF injected via noninfarct-related artery could induce angiogenesis, reduce apoptosis and ameliorate heart function, and the cardiac protective effects of 1 x 10(10) Pfu Ad5-HGF is of most significance.

Point-of-care test of heart-type fatty acid-binding protein for the diagnosis of early acute myocardial infarction.

AIM: To investigate the efficacies of point-of-care test of heart-type fatty-acid binding protein (H-FABP) and its combinations with the conventional biomarkers in the diagnosis of early acute myocardial infarction (AMI). METHODS: 227 patients suspected of AMI were consecutively recruited in two centers. Biomarkers including H-FABP, myoglobin (MYO), creatine kinase-myocardial band (CK-MB) and cardiac troponin T (cTnT) were determined simultaneously at admission. AMI was defined according to the universal definition of myocardial infarction. Chi-Square test was adopted for the analysis. RESULTS: In patients presenting within 12 h of symptom onset, the sensitivity of H-FABP[93.0% (95% CI: 86.6%-96.9%)] was significantly higher than that of initial CK-MB [67.5% (95% CI: 58.1%-76.0%), P<0.0001], cTnT [69.3% (95%CI: 60.0%-77.6%), P<0.0001] and MYO [68.6% (95% CI: 54.1%-80.9%), P<0.05]. The negative predictive value of H-FABP [92.8% (95%CI: 86.3%-96.8%)] was significantly higher than that of initial CK-MB [74.7% (95% CI: 66.8%-81.5%), P<0.001] and cTnT [75.9% (95% CI: 68.1%-82.6%), P<0.001]. The sensitivity of H-FABP+cTnT combination [94.7% (95% CI: 88.9%-98.0%)] was significantly higher than that of admission cTnT [69.3% (95% CI: 60.0%-77.6%), P<0.0001], CK-MB+cTnT [75.4% (95% CI: 66.5%-83.0%), P<0.0001] and MYO+CK-MB+cTnT [74.5% (95% CI: 60.4%-85.7%), P<0.05]. The negative predictive value of H-FABP+cTnT [94.5% (95% CI: 88.4%-98.0%] was significantly higher than that of initial cTnT [75.9% (95% CI: 68.1%-82.6%), P<0.001] and CK-MB+cTnT [79.1% (95% CI: 71.2%-85.6%), P<0.001]. Subgroup analysis showed that the superiorities of both the sensitivities and the negative predictive values of H-FABP and H-FABP+cTnT combination occurred only in patients who presented within 6 h of the symptom onset. CONCLUSION: Point-of-care test of H-FABP can be used as a valuable biomarker to detect or exclude an early-stage AMI. Combining H-FABP and cTnT provides the best performance for early AMI diagnosis.

[Hepatocyte growth factor attenuates ischemia/reperfusion induced cardiomyocyte apoptosis via downregulating calcium sensing receptor expression].

OBJECTIVE: To examine whether the anti-apoptotic effect of hepatocyte growth factor (HGF) in cardiomyocytes underwent ischemia/reperfusion (I/R) is associated with downregulation of calcium sensing receptor (CaSR) mRNA expression. METHODS: Neonatal rat cardiomyocytes were isolated and randomly divided into 7 groups: control, I/R, GdCl(3), GdCl(3) + NiCl(2) + CdCl(2), GdCl(3) + LY294002, GdCl(3) + HGF, GdCl(3) + HGF + LY294002.I/R was established by incubating primary neonatal rat ventricular cardiomyocytes in ischemia-mimetic solution for 2 h, then reincubated in normal culture medium for 24 h. Cardiomyocyte apoptosis was detected by TUNEL. The expression of CaSR mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR). The expression of Caspase-3, Bcl-2 and Phosphoinositide-3 Kinase (PI3K) was analyzed by Western blot. RESULTS: I/R enhanced the expression of CaSR mRNA (I/R: 2.62 ± 0.41, control: 1.00 ± 0.31, P < 0.01) and cardiomyocyte apoptosis [I/R: (15.32 ± 2.54)%, control: (2.90 ± 1.45)%, P < 0.01]. GdCl(3) further increased the expression of CaSR mRNA (GdCl(3): 4.46 ± 0.62, I/R: 2.62 ± 0.41, P < 0.01) and cardiomyocyte apoptosis [GdCl(3): (25.36 ± 2.60)%, I/R: (15.32 ± 2.54)%, P < 0.01], along with upregulation of Caspase-3 (GdCl(3): 1.93 ± 0.28, I/R: 1.50 ± 0.21, P < 0.01), downregulation of Bcl-2 (GdCl(3): 0.82 ± 0.18, I/R: 1.71 ± 0.30, P < 0.01) and PI3K phosphorylation inhibition (I/R: 0.87 ± 0.08, GdCl(3): 0.61 ± 0.07, P < 0.01). Combination of GdCl(3) with LY294002 further enhanced cardiomyocytes apoptosis [GdCl(3) + LY294002: (32.6 ± 3.42)%, GdCl(3): (25.36 ± 2.60)%, P < 0.01] but did not affect CaSR mRNA expression (GdCl(3) + LY294002: 4.27 ± 0.56, GdCl(3): 4.46 ± 0.62, P > 0.05). HGF decreased I/R- and GdCl(3)-induced apoptosis [GdCl(3) + HGF: (11.8 ± 1.89)%, GdCl(3): (25.36 ± 2.60)%, P < 0.05] by suppressing Caspase-3 (GdCl(3) + HGF: 1.12 ± 0.23, (GdCl(3): 1.93 ± 0.28, P < 0.05; GdCl(3) + HGF + LY294002: 1.87 ± 0.31, GdCl(3) + LY294002: 3.86 ± 0.47, P < 0.05) and promoting Bcl-2 (GdCl(3) + HGF: 2.56 ± 0.54, GdCl(3): 0.82 ± 0.18, P < 0.05; GdCl(3) + HGF + LY294002: 1.68 ± 0.28, GdCl(3) + LY294002: 0.68 ± 0.13, P < 0.05) and PI3K phosphorylation expression (GdCl(3) + HGF: 2.87 ± 0.21, GdCl(3): 0.61 ± 0.07, P < 0.05; GdCl(3) + HGF + LY294002: 2.01 ± 0.14, GdCl(3) + LY294002: 0.44 ± 0.10, P < 0.05) in accordance with downregulation of CaSR mRNA expression (GdCl(3) + HGF: 1.46 ± 0.37, GdCl(3): 4.46 ± 0.62, P < 0.01). CONCLUSION: HGF exerts protective role in I/R-induced apoptosis at least in part by inhibiting CaSR mRNA expression along with promoting Bcl-2, suppressing Caspase-3 expression and stimulating PI3K phosphorylation signaling pathway.