Potential proarrhythmic effect of cardiac resynchronization therapy during perioperative period: data from a single cardiac center / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cardiac resynchronization therapy (CRT) could improve heart function, symptom status, quality of life and reduce hospitalization and mortality in patients with severe heart failure (HF) with optimal medical management. However, the possible adverse effects of CRT are often ignored by clinicians.</p><p><b>METHOD</b>A retrospective analysis of CRT over a 6-year period was made in a single cardiac center.</p><p><b>RESULTS</b>Fifty-four patients were treated with CRT(D) device, aged (57 ± 11) years, with left ventricular ejection fraction of (32.1 ± 9.8)%, of which 4 (7%) developed ventricular tachycardia/ventricular fibrillation (VT/VF) or junctional tachycardia after operation. Except for one with frequent ventricular premature beat before operation, the others had no previous history of ventricular arrhythmia. Of the 4 patients, 3 had dilated cardiomyopathy and 1 had ischemic cardiomyopathy, and tachycardia occurred within 3 days after operation. Sustained, refractory VT and subsequent VF occurred in one patient, frequent nonsustained VT in two patients and nonparoxysmal atrioventricular junctional tachycardia in one patient. VT was managed by amiodarone in two patients, amiodarone together with beta-blocker in one patient, and junctional tachycardia was terminated by overdrive pacing. During over 12-month follow-up, except for one patient's death due to refractory heart and respiratory failure in hospital, the others remain alive and arrhythmia-free.</p><p><b>CONCLUSIONS</b>New-onset VT/VF or junctional tachycardia may occur in a minority of patients with or without prior history of tachycardia after biventricular pacing. Arrhythmia can be managed by conventional therapy, but may require temporary discontinuation of pacing. More observational studies should be performed to determine the potential proarrhythmic effect of CRT.</p>

R25G mutation in exon 1 of LMNA gene is associated with dilated cardiomyopathy and limb-girdle muscular dystrophy 1B / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mutations of the LMNA gene encoding lamin A and C are associated with dilated cardiomyopathy (DCM), conduction system defects and skeletal muscle dystrophy. Here we report a family with a mutation of the LMNA gene to identify the relationship between genotype and phenotype.</p><p><b>METHODS</b>All 30 members of the family underwent clinical and genetic evaluation. A mutation analysis of the LMNA gene was performed. All of the 12 exons of LMNA gene were extended with polymerase chain reaction (PCR) and the PCR products were screened for gene mutation by direct sequencing.</p><p><b>RESULTS</b>Ten members of the family had limb-girdle muscular dystrophy (LGMD) and 6 are still alive. Two patients suffered from DCM. Cardiac arrhythmias included atrioventricular block and atrial fibrillation; sudden death occurred in 2 patients. The pattern of inheritance was autosomal dominant. Mutation c.73C > G (R25G) in exon 1 encoding the globular domains was confirmed in all of the affected members, resulting in the conversion of arginine (Arg) to glycine (Gly).</p><p><b>CONCLUSIONS</b>The mutation R25G in exon 1 of LMNA gene we reported here in a Chinese family had a phenotype of malignant arrhythmia and mild LGMD, suggesting that patients with familial DCM, conduction system defects and skeletal muscle dystrophy should be screened by genetic testing for the LMNA gene.</p>

Effect of AP-1 decoy oligodeoxynucleotides on neonatal rat cardiac fibroblast proliferation and collagen synthesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the inhibitory effects of AP-1 decoy oligodeoxynucleotides (ODNs) on angiotensin II (AngII)-induced proliferation and collagen synthesis in neonatal rat cardiac fibroblasts (CFs).</p><p><b>METHODS</b>The CFs of neonatal SD rats were cultured in serum-free medium for 24 h and stimulated with 10(-7) mol/L AngII in the presence of AP-1 decoy ODNs or mutational AP-1 decoy ODNs at varied concentrations. MTT assay was employed for quantitative evaluation of the CF proliferation. Collagen synthesis in the CFs was assessed with hydroxyproline, and the cell cycle distribution determined with flow cytometry (FCM).</p><p><b>RESULTS</b>With the increase of the concentration of AP-1 decoy ODNs, the absorbance at 490 nm (OD490) of the CFs decreased gradually as shown by MTT assay. Treatment with 100 or 200 nmol/L AP-1 decoy ODNs resulted in significantly lowered OD490 of the CFs as compared with that of AngII group. The concentration of hydroxyproline increased significantly after treatment with 10(-7) mol/L AngII in comparison with the control group (P<0.05). Hydroxyproline concentration in cells treated with 100 or 200 nmol/L AP-1 decoy ODNs was significantly lower than that in the 10(-7) mol/L AngII-treated cells. AP-1 decoy ODNs decreased the cell percentage in S phase and increased hydroxyproline concentration, but increased the percentage of cells in G0/G1 phase. AP-1 decoy ODNs at 100 and 200 nmol/L did not obviously affect AngII-induced CF proliferation and collagen synthesis (P<0.01).</p><p><b>CONCLUSION</b>AP-1 decoy can inhibit AngII-induced rat CF proliferation and collagen synthesis possibly by affecting the cell cycle distribution.</p>

The Effect of Activator Protein-1 Decoy Oligodeoxynucleotides on the Collagen Ⅰ and Ⅲ Expression in Rat Cardiac Fibroblast Cells Induced by Angiotension Ⅱ / 中华高血压杂志

Objective To investigate the effects of activator protein-1(AP-1)decoy oligodeoxynucleotides (ODNs)on the myocardial fibrosis induced by angiotension Ⅱ(Ang Ⅱ)in vitro.Methods CFs of neonatal Spra- gue-Dawley(SD)rats were isolated by trypsin digestion method.CFs were co-cultured with 10~(-7)mol/L Ang Ⅱ in the presence of different concentration of activator protein-1(AP-1)decoy ODNs or mutational AP-1 decoy ODNs for 24 h.Collagen synthesis was assessed by hydroxyproline and the mRNA expression of collagen Ⅰ,collagen Ⅲ.Results The concentration of hydroxyproline increased significantly after treated by 10~(-7)mol/L Ang Ⅱ;decoy ODNs on the range of 10-200 nmol/L dose dependently decrease synthesis of collagen;Ang Ⅱ stimulates mRNA expression of collagen Ⅲ(1.04?0.07 vs 1.63?0.071,n=3,P