Prevention Of Arrhythmias Research Articles

Propranolol efficiency in prevention of sustained ventricular tachycardia in patients with implanted cardioverter-defibrillator: a case series

Propranolol efficiency in prevention of sustained ventricular tachycardia in patients with implanted cardioverter-defibrillator: a case series

Antiarrhythmic Drug Therapy for Maintaining Sinus Rhythm Early after Pulmonary Vein Ablation in Patients with Symptomatic Atrial Fibrillation

The optimal pharmacological treatment for patients early after ablation of atrial fibrillation (AF) is still not clear. We analyzed if concomitant antiarrhythmic drug (AAD) therapy significantly alters early recurrence of AF/atrial tachycardia (AT) following pulmonary vein ablation (PVA). For the first 2months after PVA, 274 patients (age 62±10years; 66% male) were individually scheduled for concomitant treatment with beta-adrenergic blocking agents (BB) or AAD therapy. Primary endpoint of this study was a composite of (1) AF/AT lasting more than 30seconds; (2) symptomatic AF/AT recurrence requiring intervention; or (3) intolerance to the antiarrhythmic agent given. Univariate and multivariate analysis was performed to evaluate predictors for successful AAD therapy. Early after PVA, patients were treated with BB (n=89), flecainide (n=99), sotalol (n=37), dronedarone (n=29), or amiodarone (n=115). Ninety-five patients received a combination of AAD therapy and BB. A total of 369 observation periods were analyzed. Over the first 2months following PVA, AF/AT recurrences were found in 42% of patients. No significant difference regarding freedom from AF/AT recurrence with regard to different drug therapies was observed (P=0.769). In multivariate analysis, none of the parameters were significant to predict success of AAD therapy. In nine observations, AAD therapy was terminated due to side effects presumably related to the respective agent. Following PVA, AAD therapy is not superior to BB treatment for the prevention of early atrial arrhythmias. Furthermore and confirmed by multivariate analysis, no drug was superior to another regarding the maintenance of sinus rhythm.

Stress status and ventricular fibrillation in long QT syndrome

The long QT syndrome (LQTS) is a rare hereditary disorder in which affected subjects are exposed to ventricular tachyarrhythmia leading to sudden cardiac death. In these patients the prevention of ventricular arrhythmias could be difficult because of a sudden increase of adrenergic level which could trigger arrhythmic storms [1–18]. We present the case of a 56 yearold patient who arrived to the emergency room because of recurrent syncopal episodes. In his clinical history there was hypertension, diabetes newly diagnosed, and a diagnosis of congenital LQTS (Fig. 1A). For these reasons he carried out periodic cardiologic evaluations by 24-hour cardiac Holter ECG monitoring which showed us a stable and event-free clinical picture [19–27]. Over the last three weeks, the patient had been affected by a severe stress picture caused either by his job or family problems. During observation period, several episodes of torsades de pointes took place (Fig. 1B). Some of these episodes turned on ventricular fibrillation that was immediately treated by effective electrical shock. The patient was treated with beta-blockers and then with temporary intracavitary cardiac pacing because of a sinus bradycardia as possible trigger of the arrhythmic storms (Fig. 2A). Blood tests were normal. Coronary angiography showed no significant coronary artery lesions (Fig. 2B) and the patient was implanted with a dual chamber ICD to prevent sudden death and to perform an atrial pacing in case of torsades de pointes recurrence due to a bradycardia status. After discharge, in addition to medical therapy with beta-blockers, a stressless lifestyle has been recommended. During the follow-upperiod, the device-interrogation never showed ventricular arrhythmias.

THE EFFICACY OF MELDONIUM IN REDUCTION OF CARDIAC ELECTRICAL INSTABILITY IN PATIENTS WITH ISCHEMIC STROKE

Aim. To study meldonium effect in the combination therapy for ventricular repolarization disorders and cardiac electrical instability in patients with ischemic stroke. Material and methods. Patients (n=46) with acute phase of ischemic stroke were included in a randomized, open-label, uncontrolled study. Patients were randomized into two groups. Group 1 patients (n=25) had been receiving meldonium (Mildronate;Grindex,Latvia;Pharmstandard,Russia), 1.0 g/day intravenously once daily, as a part of standard therapy for 10 days since admission to the hospital. Group 2 patients (n=21) had standard therapy alone. A standart 12-lead ECG, ventricular late potentials (VLP), 24-hour Holter monitoring, troponin test were performed at the baseline and after 10 days. Results. Patients of the group 1 as compared to the group 2 demonstrated more significant positive effect on the clinical condition of patients with ischemic stroke, ventricular repolarization, reduction of frequency (from 3.7±0.5 to 2.1±0.4; p<0.05) and duration (from 6.6±1, 3 to 4.0±1.1 min; p<0.05) of painless myocardial ischemia episodes and VLP (from 48 to 32%). Conclusion. Adding meldonium to standard therapy in patients with acute phase of ischemic stroke can have a positive effect on the clinical condition, repolarization disorders on ECG, frequency of VLP and episodes of painless myocardial ischemia detection. This may have a positive effect on the electrical stability and prevention of cardiac arrhythmias.

Assessment of heart rate turbulence in hypertensive patients: rationale, perspectives, and insight into autonomic nervous system dysfunction.

Background:Heart rhythm turbulence is classically impaired in patients with previous myocardial infarction and congestive heart failure and is poorly investigated in patients with essential hypertension.Objective:To evaluate heart rhythm turbulence parameters (turbulence onset, (TO); turbulence slope, (TS) in a series of hypertensive patients while gaining insight into autonomic nervous system dysfunction.Setting and Design:University hospital, cross-sectional monocentric study.Materials and Methods:Heart rhythm turbulence was assessed in 50 hypertensive (case group) and 40 normotensive patients (control group).Results:TO and TS were found independently correlated with hypertension. The mean TO was found at -1.64% ± 2.85% in the normotensive patients compared to 1.21% ± 1.95% in the hypertensive patients; the mean TS was found at 4.29 ± 3.18 ms/RR in the normotensive patients compared to 2.27 ± 0.93 ms/RR in the hypertensive patients. Hypertension has a predictive value on heart rhythm turbulence impairment (OR 4.99, 95% CI 1.28-19.41, P = 0.02). Insights into the role of autonomic nervous system dysfunction for the management of hypertensive patients and prevention of malignant ventricular arrhythmia are presented and discussed with regard to heart rhythm turbulence.Conclusion:Essential hypertension is correlated with blunted heart rhythm turbulence parameters.

Ventricular arrhythmia in patients with prolonged QT interval during liver transplantation: two cases report.

QT interval prolongation is associated with an increased risk of ventricular arrhythmia in various conditions. Cardiac electrophysiologic abnormalities including QT interval prolongation are well documented in patients with advanced liver cirrhosis. We report two cases of patients with QT interval prolongation on preoperative electrocardiography who exhibited repetitive ventricular arrhythmias with significant hemodynamic deterioration during liver transplantation. For the treatment and prevention of ventricular arrhythmias during the intraoperative period, we performed intravenous administration of lidocaine and isoproterenol, corrected imbalances of electrolytes including potassium and magnesium, and prepared a defibrillator. These cases emphasize that preoperative recognition of QT interval prolongation and adequate management to prevent fatal arrhythmias are important in patients undergoing liver transplantation.

An Oxygen Therapy Prevents Ventricular Arrhythmia in Patients with Diastolic Heart Failure and Sleep Apnea

The background and purpose Diastolic and systolic heart failure (DHF and SHF) are the different clinical subsets. Because many heart failure patients have sleep apnea syndrome (SAS), oxygen supply improves the patient’s prognosis. Thus, the purpose of this study was to compare the effects of oxygen treatment for premature ventricular contractions (PVCs) suppression in patients between DHF and SHF. Methods and subjects Patients with heart failure (BNP>80 pg/ml), SAS (AHI> 5) and frequent PVCs (>30/h) were admitted to the hospital for at least 2 consecutive nights. On the first night, the respiratory and Holter monitoring was performed without nasal oxygen treatment; the same monitor with nasal oxygen therapy (3 L/min) was performed on the second night. Essential results The DHF patients (more than 40% of LVEF, n=7) showed a significant decline of PVC numbers (63.1 ± 33.0% post/pre) compared to those (119.8 ± 45.3% post/pre, p<0.05) of the SHF patients (less than 40% of LVEF, n=8) by the oxygen treatment. The DHF patients also showed higher SDNN (253.0 ± 260.0 ms) levels compared to those of SHF patients (52.9 ± 22.4 ms, p<0.05). However, AHI and BNP levels were compatible between the two groups. The principal conclusion The oxygen treatment may be useful for prevention of ventricular arrhythmia in patients with DHF and SAS.

Personalized arrhythmia prevention: Do the I’s have it?

In 1990, Rigat et al described a common polymorphism in a noncoding intron of the angiotensin-converting enzyme (ACE) gene. The polymorphism encompasses the presence (I 1⁄4 insertion) or absence (D 1⁄4 deletion) of a 287-basepair DNA fragment and is associated with almost half of the known variation in ACE serum levels. There may be homozygosity for the insertion allele (I/I), homozygosity for the deletion allele (D/D), and heterozygosity (I/D). Mean serum ACE levels are lowest in I/I subjects and highest in D/D; heterozygotes are intermediate. It has been hypothesized that it is not the polymorphism itself that produces the variation but rather a regulatory variant of the ACE gene in strong linkage dysequilibrium with the polymorphism. In this issue of HeartRhythm, Smith et al, in a prospective observational study, examine the influence of the I/D polymorphism on postoperative tachyarrhythmias in pediatric patients after open heart surgery for congenital heart disease. In a previous study, the same group demonstrated that postoperative junctional ectopic tachycardia developed in 31% of D/D children but only in 16% of I/I children. The current study examines a larger cohort and a wider spectrum of tachyarrhythmia. Subjects from the previous study were included. Similar to their previous study, the presence of D/D or I/D was independently associated with a 60% increase in the risk of postoperative tachyarrhythmia. Of considerable interest is the finding of a novel pharmacogenetic interaction whereby preoperative ACE inhibitor administration was independently associated with a 47% reduction in the odds of postoperative tachyarrhythmia. This reduction was virtually completely driven by a 5-fold reduction in tachyarrhythmia among I/I children. For a pediatric study, the subject numbers are relatively large; however, the confidence intervals for the reduction of arrhythmia among I/I children are wide (odds ratio 0.19, 95% confidence interval 0.04–0.88, P 1⁄4 .02). Caution is required in interpreting the magnitude and strength of the

Management of arrhythmias in patients with a tetralogy of Fallot

Although arrhythmias are commonly found in patients with all different types of congenital heart disease, perhaps no patient is at higher risk of late development of arrhythmias that may result in sudden death than in the patient following tetralogy of Fallot repair. Despite major improvement in the surgical repair of this disease, a significant percentage of these patients continue to remain at risk for the late development of arrhythmias, and a small percentage will develop life-threatening arrhythmias and sudden death. Which patients remain at highest risk is still not clearly delineated. Diligent arrhythmia surveillance and aggressive treatment strategies are necessary to minimise this risk. This article highlights important strategies to manage arrhythmia development and prevention in this patient population.

Amiodarone-Induced Thyroid Storm Treated with Plasmapheresis and Thyroid Artery Ablation

Introduction Amiodarone is a class III antiarrhythmic drug commonly used for treatment and prevention of cardiac arrhythmias. It is associated with a number of side effects including thyroid dysfunction due to its high iodine content and direct toxic effects. In the United States, 3 to 5 percent of patients treated with amiodarone develop hyperthyroidism. 1 Amiodarone-induced thyrotoxicosis (AIT) is divided into 2 types. Type 1 is associated with increased synthesis of thyroid hormone, whereas type 2 is associated with excessive release of thyroxine (T4) and triiodothyronine (T3) from a destructive process. The diagnosis of thyroid storm is based upon clinical findings which are exaggerations of typical hyperthyroidism involving the central nervous, gastrointestinal, and cardiovascular systems. The most accepted criteria to diagnose thyroid storm was created by Burch and Wartofsky who introduced a scoring system in 1993. 2 It provided a criterion to grade severity of thermoregulatory, cardiovascular, and central nervous system dysfunctions with scores greater than 45 being highly suggestive of thyroid storm. Medical therapy for thyroid storm is centered on thionamides, glucocorticoids, and beta-blockers. Plasma exchange and thyroidectomy have been used in patients whose hyperthyroidism is refractory to aggressive medical therapy. In our case, thyroid artery ablation also was utilized when too ill to undergo surgical thyroidectomy.

Continuous infusion of magnesium–lidocaine mixture for prevention of ventricular arrhythmias during on-pump coronary artery bypass grafting surgery

BackgroundDuring on-pump coronary artery bypass grafting (CABG) surgery, the incidence of reperfusion ventricular fibrillation (VF) is high and post-bypass ventricular arrhythmias are common. Both reperfusion VF and ventricular arrhythmias can cause additional myocardial injury to the already ischemic myocardium. This trial aimed to test the assumption that continuous combined magnesium and lidocaine infusion would be efficient and long lasting for the prevention of post-myocardial vascularization ventricular arrhythmias including VF.MethodsEighty ASA III patients, who were candidates for CABG surgery, were randomly assigned into two groups: Group I (control group, n = 40) and Group II (Group ML, n = 40). After endotracheal intubation, patients of control group were infused with plain normal saline in a volume equivalent to study drugs’ mixture volume. Patients of Group ML were infused with magnesium–lidocaine mixture to achieve a bolus of magnesium sulfate 2 g and lidocaine 100 mg followed by continuous infusion of Mg sulfate 500 mg/h and lidocaine 1 mg/min. The initial cardiac rhythm after aortic cross clamp (ACC) release and the occurrence of post-CPB significant ventricular arrhythmias were recorded.ResultsThe incidences of reperfusion VF and post-CPB ventricular arrhythmias in Group ML were significantly lower than that in control group (22.5% vs. 72.5%) (P < 0.001) and (7.5% vs. 25%) (P < 0.05), respectively. However, in Group ML, this beneficial effect was associated with higher incidence of sinus bradycardia (72.5% vs. 17.5%) and hence pacing needs (22.5% vs. 0.0%) when compared with control group.ConclusionOur study concluded that, during on-pump CABG surgery, the combined administration of magnesium and lidocaine as a bolus dose starting after intubation followed by continuous infusion reduced the incidence of reperfusion VF by 62% and post-CPB ventricular arrhythmias by 70% on expense of increased the incidence of sinus bradycardia and pacing.

Update on anesthesia for craniotomy

In this review, we present an update on the relationship between anesthesia and intraoperative hemodynamic complications, early postanesthesia recovery, postoperative pain and postoperative nausea and vomiting after craniotomy. We also review latest advances in education and research in neuroanesthesia for brain surgery. Insights from clinical reports published from January 2012 to April 2013 on anesthesia for craniotomy will be summarized. Recent findings address the need for a tight intraoperative hemodynamic monitoring - that should include aggressive prevention of arterial hypotension and cardiac arrhythmias - and a careful management of fluids and electrolytes balance. Data on the relationship between anesthesia (selection of anesthetics used intraoperatively) and early recovery demonstrate a limited benefit when ultra-short acting drugs (as remifentanil vs fentanyl) are used. Evidence on postoperative pain and postoperative nausea and vomiting contribute to define how to better prevent and treat these complications. Latest guidelines on training and research in neuroanesthesia define unique end points in this subspecialty. Neuroanesthesia for craniotomy should be aimed to ensure intraoperative loss of consciousness (unless awake craniotomy is the selected anesthesiological approach), pain control and an uneventful postoperative recovery, but should also be addressed to manipulate physiological variables including cerebral blood flow and to obtain optimal surgical exposure.

Downregulation of miR-151-5p Contributes to Increased Susceptibility to Arrhythmogenesis during Myocardial Infarction with Estrogen Deprivation

Estrogen deficiency is associated with increased incidence of cardiovascular diseases. But merely estrogen supplementary treatment can induce many severe complications such as breast cancer. The present study was designed to elucidate molecular mechanisms underlying increased susceptibility of arrhythmogenesis during myocardial infarction with estrogen deprivation, which provides us a new target to cure cardiac disease accompanied with estrogen deprivation. We successfully established a rat model of myocardial ischemia (MI) accompanied with estrogen deprivation by coronary artery ligation and ovariectomy (OVX). Vulnerability and mortality of ventricular arrhythmias increased in estrogen deficiency rats compared to non estrogen deficiency rats when suffered MI, which was associated with down-regulation of microRNA-151-5p (miR-151-5p). Luciferase Reporter Assay demonstrated that miR-151-5p can bind to the 3′-UTR of FXYD1 (coding gene of phospholemman, PLM) and inhibit its expression. We found that the expression of PLM was increased in (OVX+MI) group compared with MI group. More changes such as down-regulation of Kir2.1/IK1, calcium overload had emerged in (OVX+MI) group compared to MI group merely. Transfection of miR-151-5p into primary cultured myocytes decreased PLM levels and [Ca2+]i, however, increased Kir2.1 levels. These effects were abolished by the antisense oligonucleotides against miR-151-5p. Co-immunoprecipitation and immunofluorescent experiments confirmed the co-localization between Kir2.1 and PLM in rat ventricular tissue. We conclude that the increased ventricular arrhythmias vulnerability in response to acute myocardial ischemia in rat is critically dependent upon down-regulation of miR-151-5p. These findings support the proposal that miR-151-5p could be a potential therapeutic target for the prevention of ischemic arrhythmias in the subjects with estrogen deficiency.

κ-opioid Receptor Activation Prevents Against Arrhythmias by Preserving Cx43 Protein Via Alleviation of Intracellular Calcium

κ-opioid receptor (κ-OR) activation with U50,488H, a selective κ-OR agonist, has been previously demonstrated to prevent against cardiac arrhythmias via stabilizing the synthesis and degradation of an integral membrane protein, Cx43, in gap junctions. However, the exact prevention mechanism remains unclear. The present study tested the hypothesis that the kappa OR agonist U50,488H mediates the prevention of arrhythmia through the regulation of intracellular calcium leading to the preservation of Cx43 protein. By performing electrocardiogram monitoring and immunoblotting in isolated Langendorff-perfused rat hearts, high concentrations of calcium-perfused rat hearts exhibited increased cardiac arrhythmias. Diminished expression of Cx43 protein was observed. The utilization of a whole-cell patch clamp technique revealed that U50,488H inhibited L-type calcium current in single ventricular myocytes in a dose-dependent manner. These effects were blocked by nor-binaltorphimine, potent and selective κ-OR antagonists. Administration of U50,488H before myocardial ischemia resulted in an attenuated of total arrhythmia scores. The attenuation effect was blocked by nor-binaltorphimine. The attenuation effect was antagonized both by Bay K8644, a L-type calcium channel agonist, and also by the Cx43 uncoupler heptanol. Finally, immunoblotting data demonstrated that the preservation of Cx43 protein conferred by U50,488H was reversed in the presence of Bay K8644. In summary, the present study demonstrates κ-OR activation with U50,488H may confer antiarrhythmic effects via modulation of the calcium-Cx43 pathway.

Association between CHADS2 Score and the Preventive Effect of Statin Therapy on New-Onset Atrial Fibrillation in Patients with Acute Myocardial Infarction

ObjectivesNew-onset atrial fibrillation (AF) commonly occurs in patients with acute myocardial infarction (AMI). Data regarding the value of the CHADS2 score in patients hospitalized for AMI is limited. This study aimed to determine whether the CHADS2 score is associated with new-onset AF and if it can help identify the patients who will benefit most from statin use for the prevention of arrhythmia after AMI.MethodsA total of 724 consecutive AMI patients were enrolled in this study. The patients were divided into 3 groups according to their CHADS2 scores: group 1, score 0; group 2, score 1–2; and group 3, score 3–6. The study endpoint was an episode of new-onset AF that lasted more than 30 seconds during hospitalization at the coronary care unit.ResultsSeventy-eight (10.8%) patients developed new-onset AF, and 273 (37.7%) were on a statin upon admission. The incidence of new-onset AF increased significantly from 5.8% in group 1 to 11.3% in group 2 and 14.3% in group 3 (χ2 for linear trend, P = 0.017). Statin use (odds ratio [OR], 0.22; 95% CI, 0.06–0.85) and CHADS2 score (OR, 1.53; 95% CI, 1.02–2.28) were independent predictors of new-onset AF in AMI patients. Patients with CHADS2 score ≤2 had significantly reduced C-reactive protein level and lower risk of developing new-onset AF if they were taking statins (P < 0.05). Multivariate logistic regression analysis demonstrated the benefit of statin use for preventing new-onset AF in patients with CHADS2 scores ≤2 (OR, 0.34; 95% CI, 0.14–0.81).ConclusionsThe CHADS2 score is a convenient scoring system for predicting the incidence of new-onset AF and may help in identifying the patients who will benefit most from statin use for the prevention of arrhythmia after AMI.

Reuse of Cardiac Rhythm Control Devices: A Review

Cardiac rhythm control devices i.e. pacemakers, implantable cardioverter-defibrillators (ICDs) and biventricular pacemakers are at times lifesaving treatment and prevention of arrhythmia. But, despite definite indications, many people in the developing countries cannot afford these devices due to high cost, and succumb to premature death. On the other hand, after implantation, pacemakers and ICDs are sometimes underutilized because of premature explantation due to death of the recipient, device infection, or upgradation, leaving a considerable extent of serviceable battery life unused. Majority of these explanted devices are simply thrown away. Though made for single use, a growing body of evidence indicates the safety, efficacy and feasibility of reimplantation of the prematurely explanted devices in patient in need who is otherwise unable to afford a new one. Patients, physicians, morticians, and even the general public support the idea of device donation and recycling. A number of organizations around the world have engaged themselves in this benevolent effort, and t he feasibility of device reutilization programme has already been established. However, some logistic, legal and ethical concerns are yet to be solved. The statutory bodies and professional organizations should address the issue of device recycling to solve the unsolved issues and formulate standard practice guidelines. In that case, such medical wastes may turn into invaluable resources, and help ensuring equitable medical care throughout the world. Cardiovascular Journal Volume 6, No. 1, 2013, Page 52-59 DOI: http://dx.doi.org/10.3329/cardio.v6i1.16116

Effect of Statin Therapy In Ventricular Arrhythmias In Patient With Acute Anterior Myocardial Infarction

Background: Though statins are widely used in acute coronary syndrome (ACS), there is a paucity of information on the efficacy of high dose statin therapy in reducing the incidence of ventricular arrhythmias after acute myocardial infarction. Arrhythmias are relatively common in acute myocardial infarction (AMI) anterior, and sometimes progress to cardiac arrest. This study was planned to evaluate the role of high dose atorvastatin therapy in prevention of ventricular arrhythmias after acute anterior myocardial infarction. Methods: This study was conducted in NICVD from December 2010 to October 2011. Total 200 patients with newly diagnosed acute anterior myocardial infarction who received thrombolytic therapy were included in the study. They were divided into two groups. Group I (n=100) was selected for high dose atorvastatin therapy and group II (n=100) was selected for conventional doses of atorvastatin therapy. 24 hours Holter monitoring was performed 48 hours after hospital admission to evaluate arrhythmia. Results: Majority of the patients belonged to age range of 40 to 59 years with a male predominance. Patient characteristics regarding age, sex, drug use, risk factors for ventricular arrhythmia, body mass index, left ventricular ejection fraction were similar in two study groups. There was no electrolyte imbalance or renal impairment in any patient in either group. A significant difference in frequency of ventricular arrhythmias was found between the two groups. Ventricular premature beats were found in 66% patients in group I and 97% patients in group II (p=0.001) whereas non sustained ventricular tachycardia were observed in 0% and 4% in group I and group II respectively. Conclusion: High dose atorvastatin therapy is associated with lower frequency of ventricular arrhythmias after acute anterior myocardial infarction. Cardiovascular Journal Volume 6, No. 1, 2013, Page 37-42 DOI: http://dx.doi.org/10.3329/cardio.v6i1.16113

New single nucleotide polymorphisms associated with supraventricular arrythmias in patients with pacemaker implantation: genome-wide association approach and pooled DNA strategy

Aims: The objective of this study was to use genome-wide association approach and pooled DNA strategy to search for new genomic loci associated with inter-individual differences in patients with pacemakers placed for sinus node dysfunction in form of sick sinus syndrome (SSS) or tachycardia-bradycardia syndrome (TB) and/or atrio-ventricular (AV) conduction disturbances (AV blocks). Methods and results: Study cohort consisted of 619 patients (recruited from the areas of central Poland) with pacemaker placement and 66 control patients (no pacemaker implantation or history of atrial arrhythmias). We tested association of single nucleotide polymorphisms (SNPs) genotyped using high density microarray platform with 3 groups separated on the basis of the diagnosis associated with pacemaker implantation (AV n=233, SSS n=171, and TB n=215), followed by individual genotyping of most significant SNPs identified in the microarray genomic scan. From the number of 23 initially genotyped SNPs we identified SNP rs2200733 located in the proximity of the PITX2 gene, which showed statistically significant differences between controls (MAF=11%) and 3 pacemaker groups (TB 24.2%; SSS 13.3% and AV 17.4%). The highest statistical significance (p value of 0.005 for minor allele frequency difference in individual genotyping) was observed for SNP in the TB group and AV group (p=0.016) when compared with control. Conclusions: Previous genome-wide association studies implicated a region of human chromosome 4q25 in familial atrial fibrillation (AF) and atrial flutter (AFl), approximately 150 kb distal to the PITX2 homeobox gene, a developmental left-right asymmetry (LRA) gene. In this respect the observed difference in allelic frequency for the investigated PITX2 polymorphism may be associated with the etiology underlying pacemaker placement in the TB group which was, in contrast to SSS group, associated with the frequent episodes of underlying AF. The genome-wide approach might provide an opportunity to identify novel candidate genes and pathways related to the diagnosis of cardiac arrhythmias and indication for the pacemaker implantation. In addition, our findings implicate PITX2 and PITX2-mediated LRA-signaling pathways in prevention of atrial arrhythmias.

Sympathetic reinnervation and arrhythmia prevention following cardiac ischemia-reperfusion injury

Sympathetic reinnervation and arrhythmia prevention following cardiac ischemia-reperfusion injury

Design on Monitoring Watch for Arrhythmia

The widely crowd occurred arrhythmia. Studies have shown that more than 90% patients who suffer from sudden cardiac death has arrhythmia. Therefore, the real-time monitoring of arrhythmia is of great value for cardiovascular disease prevention, treatment and prognosis. Arrhythmia is now usually detected by electrocardiogram, echocardiogram, Holter monitor, etc. Such equipments are relatively expensive, and equipment operation and result analysis need to do by professional medical personnel of medical institutions. These equipments are not suitable for household use and long-term real-time monitoring. Therefore, a portable monitoring watch for arrhythmia with real-time dynamic monitoring is designed in this paper. Not only can the watch detect the occurrence of asymptomatic arrhythmia and the time point of arrhythmia, but also can analysis and diagnosed the kind of arrhythmia. So it has important application value for arrhythmia prevention and treatment.