Effects of right ventricular nonapical pacing on cardiac function: a meta-analysis of randomized controlled trials.

BACKGROUND: A meta-analysis of randomized controlled trials (RCTs) was conducted to compare the effects of right ventricular nonapical (RVNA) and right ventricular apical (RVA) pacing on cardiac function. METHODS: A systematic literature search was performed using MEDLINE, EMBASE, and the Cochrane Library to identify RCTs comparing RVNA pacing with RVA pacing with follow-up ≥2 months. Twenty RCTs involving 1,114 patients were included. RESULTS: Compared with RVA pacing, RVNA (mainly right ventricular septum [RVS]) pacing exhibited not only excellent pacing threshold and R-wave amplitude but also higher impedance. RVNA pacing showed a significant increase in left ventricular ejection fraction (LVEF) at the end of follow-up (weighted mean difference = 3.58, 95% confidence interval = 1.80-5.35), and the effects were observed in the following subgroups: 6-month follow-up, ≤12-month follow-up, >12-month follow-up, baseline LVEF ≤45%, and baseline LVEF >45%. RVS and RVA pacing significantly differed in improving LVEF (weighted mean difference = 4.82, 95% confidence interval = 2.78-6.87). In addition, RVNA pacing resulted in a narrower QRS duration, a smaller left ventricular end-systolic volume, and a lower New York Heart Association functional class. CONCLUSIONS: This meta-analysis found that RVNA (mainly RVS) pacing exhibited satisfactory long-term lead performance compared with RVA pacing and demonstrated beneficial effects in improving LVEF after the 6-month follow-up. Furthermore, it proved superior to RVA pacing in terms of interventricular synchrony and cardiac function.

A high normal TSH level is associated with an atherogenic lipid profile in euthyroid non-smokers with newly diagnosed asymptomatic coronary heart disease.

BACKGROUND: Serum lipid profiles may be influenced by thyroid function, but the detailed mechanism remains unclear. Increasing evidence suggests that thyrotropin (TSH) may exert extra-thyroidal effects. The goal of this study was to evaluate the relationship between serum TSH levels and the lipid profiles in euthyroid non-smokers with newly diagnosed asymptomatic coronary heart disease (CHD). METHODS: This was a retrospective study of 406 euthyroid non-smokers (187 males and 219 females) with newly diagnosed asymptomatic CHD from 2004 to 2010 in Jinan, China. Lipid parameters and the levels of TSH, FT3, and FT4 were determined. Multiple linear regression analysis and Logistic regression analysis were used to assess the influence of TSH on the lipid profiles and the risks of dyslipidemia. RESULTS: The TSH level, even within the normal range, was positively and linearly correlated with total cholesterol (TC), non-high density lipoprotein cholesterol (non-HDL-C) and triglycerides (TG) (Beta = 0.173, 0.181 and 0.103, respectively, P < 0.01 in all). With 1 mIU/L rise of TSH, the levels of TC, TG and non-HDL-C will increase by 1.010, 1.064, and 1.062 mmol/L, respectively. The odds ratio of hypercholesterolemia and hypertriglyceridemia with respect to the serum TSH level was 1.640 (95% CI 1.199-2.243, P = 0.002) and 1.349 (95% CI 1.054-1.726, P = 0.017), respectively. CONCLUSIONS: TSH levels were correlated in a positive linear manner with the TC, non-HDL-C and TG levels in euthyroid non-smokers with newly diagnosed asymptomatic CHD. TSH in the upper limits of the reference range might exert adverse effects on lipid profiles and thus representing as a risk factor for hypercholesterolemia and hypertriglyceridemia in the context of CHD.

Myocardial Motion Velocity Detected by Tissue Doppler Imaging for Idiopathic Premature Ventricular Beat / 中国循环杂志

Objective: To detect the systolic and diastolic velocity in patients with idiopathic premature ventricular beat(PVB)by pulsed wave-tissue Doppler imaging (PW-TDI) techniques.Methods: There were two groups involved in this study. PVB group,n=30,patients with idiopathic PVB,and Control group,n=30,of healthy subjects. The changes of cardiac function were measured and compared between two groups by the index of myocardial motion velocity using PW-TDI techniques.Results: A total of 7 sites were studied,there were no significant differences in systolic peak velocities (Sm),time velocity integral (TVI),peak velocity of the early relaxation wave (Em),peak velocity of the later relaxation wave (Am) and Em/Am ratio (Em/Am) between the Control group and PVB group in the normal sinus beat (P＞0.05).Compared with the normal sinus beat,Sm,TVI,Em and Em/Am were significantly lower in PVB (P<0.01),while Sm,TVI,Em in the post-PVB sinus beat were significantly higher than that in normal sinus beat (P<0.01). However,there were no significant differences of Am in each site among the normal sinus beat,PVB and the post-PVB sinus beat. Conclusion: PVB and PVB-induced compensational interval could significantly influence the systolic and diastolic function of the ventricle.

Modified Maze lines plus pulmonary vein isolation created by radiofrequency catheter ablation on the atrial wall to treat atrial fibrillation in elderly / 老年心脏病学杂志（英文版）

Objective To evaluate the effect of modified Maze lines plus pulmonary vein (PV) isolation created by radiofrequency catheter ablation (RFCA) on atrial wall guided by a novel geometry mapping system in the treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Methods After regular electrophysiological study, transseptal punctures were achieved twice with Swartz L1 and R1 sheaths. PV angiographies were conducted to evaluate their orifices and branches. A balloon electrode array catheter with 64 electrodes was put in the middle of the left atrium. Atrium geometry was constructed using Ensite 3000 Navx system. Two RFCA lesion loops and three lines (modified Maze) were created on left and right atrial walls. Each lesion point was ablated for 30 seconds with preset temperature 50 (ae) and energy 30W. The disappearance or 80% decrease of the amplitude of target atrial potential and 10 to 20(|), decrease of ablation impedance were used as an index of effective ablation. Results A total of 11 patients (7 male and 4 female, mean age, 68.7±5.1 years) were enrolled. PAF history was 7.9±4.5 years. PAF could not be prevented by mean 3.1±1.6 antiarrhythmic agents in 6.3±3.4 years. None of the patients had complications with structural heart disease or stroke. Left atrial diameter was 41.3±3.6 mm and LVEF was 59.2±3.7% on echocardiography. Two loops and three lines were completed with 67.8±13.1 (73-167) lesion points. Altogether 76-168 (89.4±15.3) lesion points were created in each patient. PAF could not be provoked by rapid burst pacing up to 600 beat per minute delivered from paroxysmal coronary sinus electrode pair.Complete PV electrical isolation was confirmed by three-dimensional activation mapping. Mean procedure time was 2.7±0.6 hours and fluoroscopy time was 17.8±9.4 minutes. Patients were discharged with oral aspirin and without antiarrhythmic agents. During follow up of 6.5±1.8 months, seven patients were PAF symptom free (63.6%). PAF attacks were decreased more than 70% in two patients (18.2%). PAF frequency did not change in another two patients (18.2%). Conclusions Ensite 3000 Navx guided modified Maze lines plus PV isolation on the atrial wall is safe and feasible in the elderly patients. It has the advantages of exact procedural endpoint, shorter X-ray exposure, fewer complications and satisfied long-term effect PAF control.

Potassium channel gene expression in myocardial sleeves of pulmonary vein and effects of amiodarone on rabbits with rapid atrial pacing / 中国病理生理杂志

AIM: To investigate the potassium channel gene expression of myocardial sleeves of pulmonary vein and effects of amiodarone on rabbits with rapid atrial pacing.METHODS: Rabbits were divided into three groups(n=10),(1) the control group with sham operation and placebo;(2) the right atrial pacing(RAP) group at 600 beats/min with the placebo;(3) the amiodarone group treated for seven days with oral amiodarone at 100 mg ? kg-1 ? d-1.Based on RAP simultaneously,the messenger ribonucleic acid(mRNA) of specimen was measured by reverse transcription-polymerase chain reaction.RESULTS: Compared with the control group,Kv4.3(transient outward K+ current,Ito1) mRNA expression in RAP group was reduced by 51%(P

Comparison of atrial fibrillation inducibility due to electrical stimulation of the extrinsic vs the intrinsic cardiac autonomic innervation / 中国介入心脏病学杂志

Objective To investigate the influence of cervical vagosympathetic trunk or ganglionated plexi stimulation to the inducibility of atrial fibrillation(AF) in dogs.Methods In 16 anesthetized dogs,right cervical vagosympathetic trunk(VST) were dissected.A right thoracotomy was used to expose fat pad(FP) containing the ganglionated plexi(GP) at the caudal end of the sinus node.An electrode catheter was attached along the right superior pulmonary vein to allow programmed atrial pacing.At 2?,4? and 10? threshold atrial refractory periods(ARPs) were determined with and without VST or GP stimulation.At each pacing threshold AF inducibility was measured from the window of vulnerability(WOV).A cumulative WOV sum made of all WOVs was calculated in each group.Results In the baseline state the heart rate(HR) averaged 153?22 beats/min.Slowing of the HR by VST stimulation(79?44 beats/min) was not significantly different than with GP induced slowing(87?99 beats/min,P=NS).Furthermore,there were no significant differences between the lowest ARPs with VST stimulation and GP stimulation,accounting to 90?17 ms and 91?13 ms respectively(P=NS),but both are shorter than that in the baseline state,which was 101?20 ms(P

Distinctive Feature of Application of Radiofrequency Current Ablation to Aged Patients with Tachycardia / 介入放射学杂志

14 aged patients received radiofrequency current ablation(RFCA)to treat drug-refractory tachycardia. The success rate was 97%(13/14).In conjunction with the charcteristicaof aged patients often with long clinical history and apt to be complicated,the paper especially discussed the distinctive feature of application of RFCA to aged patients.

Spontaneous focal atrial fibrillation arising from a peripheral atrial site:separation of AF triggers from AF maintenance / 中国介入心脏病学杂志

10 minutes).The average cycle length(CL) at the RAA was 30.6?4.6 msec vs.105.2?32.0 msec at other atrial sites(P

Comparison of Clinical and Economic Effects between Catheter Radoifrequency Current Ablation and Openheart Operation for Chinese Patients with Paroxysmal Supraventricular Tachycardia / 中国介入心脏病学杂志

0. 05) in rate of success, recurrence and complication between RFCA and OHO for the patients with AVRT. Medical workers were fewer, operation, du-ration, hospital days (including days of pre-operation preparation and post-operation recovery) and days of looking after the patients in RFCA were shorter than those in OHO,p

Mechanism of heart failure with diastolic dysfunction——changes of platelet Ca~(2+),erythrocyte Ca~(2+) and Ca~(2+),Mg~(2+)-ATPase / 中国病理生理杂志

Platelet Ca~(2+), erythrocyte Ca~(2+) and Ca~(2+), Mg~(2+)-ATPase activity in erythrocyte membrane of 42 patients of mildmoderate degree heart failure (HF) with diastolic dysfunction were measured. The results showed that the patients with HF had higher level of platelet Ca~(2+) and erythrocyte Ca~(2+) content, and lower level Ca~(2+), Mg~(2+)-ATPase activity than those of control group (P