OBJECTIVES: Atrial electrical remodeling is considered to play an important role in the appearance of atrial fibrillation. The effect of atrial natriuretic peptide (ANP) on atrial electrical remodeling was evaluated in a canine atrial stimulation model. METHODS: In 15 beagle dogs, electrodes for pacing and recording were fixed on the ...

Proper atrial function is essential for overall cardiovascular performance, mainly by its four major functions, namely, bioelectrical, hormonal, metabolic and hemodynamic. With regard to the latter, atria modulate ventricular filling by smoothing the transformation of the continuous venous return to the intermittent filling pattern of the ventricles during diastole through ...

The patient is a 64-year-old male who had been implanted with a DDD-pacemaker for sick sinus syndrome in 2003. In January 2006, he experienced palpitations and visited a local hospital on the second day of occurrence. After an electrocardiography (ECG) revealed atrial flutter (AFL) during palpitation, which was resistant to ...

OBJECTIVE: To determine the univentricular and atrial function in patients following Fontan operation using tissue Doppler echocardiography (TDE). SETTING: Hospital-based outpatient clinic and inpatient unit. PATIENTS: Thirty-six patients (mean age 13 ys [2-34 ys]) after Fontan procedure and 30 healthy individuals matched for age and heart rate. MAIN OUTCOME MEASURES: ...

The morphogenesis of the sinuatrial region of embryonic hearts is still not well understood. Current matters of dispute are the topogenesis of the future pulmonary vein orifice and the topogenesis of the primary atrial septum. We analyzed the development of the sinuatrial region in chick embryos ranging from Hamburger and ...

BACKGROUND: This study evaluated and standardized a Patent Foramen Ovale (PFO) preclinical model in gross anatomic and histopathologic features. METHODS: We examined 150 necropsy-derived domestic porcine hearts, age 4-6 months for PFO prevalence, appearance, and size. Histopathologic preparations were standardized and processed identically to 24 post-mortem human hearts aged 16-62 ...

BACKGROUND: Application of fluorescence imaging of cardiac electrical activity is limited by motion artifacts and/or side effects of currently available pharmacologic excitation-contraction uncoupling agents. OBJECTIVES: The purpose of this study was to test whether blebbistatin, a recently discovered inhibitor of myosin II isoforms, can be used as an excitation-contraction uncoupler. ...

ECGs were recorded from three electrodes attached at the corners of an equilateral triangle positioned around the location of electrode V1. The atrial signal between QRST complexes was subjected to correlation function analysis to reveal differences in activation times between the electrode sites. The time differences found were used to ...

PURPOSE: To investigate left atrial volumes and function and their variability in healthy volunteers using steady state free precession (SSFP) and fast low angle shot (FLASH) sequences at both 1.5 and 3 T using both the short-axis and biplane area-length methods. MATERIALS AND METHODS: Ten healthy volunteers underwent CMR at ...

The purpose of this study was to determine the incidence of cardiovascular pathology in 50 cadavers in the dissecting room of the Department of Anatomy at Guy's Campus, King's College, London, and to demonstrate the importance of dissection in teaching the anatomy of normal and pathological hearts. After external evaluation ...

BACKGROUND: Positive Turbulence onset (TO) after atrial premature complexes (APCs) was found temporally related to spontaneous episodes of atrial fibrillation. This study tested the hypothesis that heart rate turbulence (HRT) after APCs is influenced by APC prematurity independently of the prematurity of conducted ventricular complexes. METHODS: We studied 33 patients ...

Channelopathies are among the major causes of syncope or sudden cardiac death in patients with structurally normal hearts. In these patients, the atrium, ventricle or both could be affected and reveal different presentations. In this case, we present a patient with an apparently structurally normal heart and recurrent syncope, presented ...

The myocardial performance index (MPI) was assessed in 30 patients with limb girdle muscle dystrophy (LGMD) with a normal left ventricular ejection fraction (greater than 50%), as well as in 30 age- and sex-matched healthy adults with a left ventricular ejection fraction greater than 50%. MPIs derived by pulsed-wave Doppler ...

BACKGROUND AND PURPOSE: Recent reports suggest that n-3 (omega-3) polyunsaturated fatty acids (PUFAs) may reduce atrial fibrillation (AF). Reduction of the atrial effective refractory period (ERP) is believed to be an important early remodeling event that favors the development and perpetuation of AF. We hypothesized that n-3 PUFAs would attenuate ...

BACKGROUND: Although coexistence of atrioventricular conduction disturbances with sick sinus syndrome (SSS), so-called binodal disease (BND), is a frequently encountered disorder, its clinical significance and electrophysiological characteristics remain unknown. METHODS AND RESULTS: One hundred and seven patients with SSS were divided into BND (n=30) and N-BND groups (n=77). Sinus cycle ...

OBJECTIVES: Severe idiopathic tricuspid regurgitation (TR) occurs in the aged, but the mechanism of TR is unclear and there is little information on atrial abnormalities associated with this condition. This study retrospectively analyzed patients with severe functional TR presenting with common clinical features suggesting a distinct syndrome. METHODS: Eleven patients ...

Preventive atrial pacing and antitachycardia pacing have been proposed for the treatment of atrial fibrillation and associated arrhythmias in patients with indications for device implantation. Preventive algorithms provide overdrive atrial pacing, reduction of atrial premature beats, and prevent short-long atrial cycles with good patient tolerance. However, clinical trials testing preventive ...

BACKGROUND: Success of the maze procedure after mitral operations with large left atria and permanent atrial fibrillation remains suboptimal. Current technique variations tend to obscure the decision-making algorithm in these patients. A single energy-source approach for the surgical management of patients with large left atria and permanent atrial fibrillation is ...

OBJECTIVES: To investigate the impact of myocardial perfusion on left atrial remodeling and its determinants after primary percutaneous coronary intervention for acute myocardial infarction. BACKGROUND: Left atrial volume is an important predictor of morbidity and mortality in acute myocardial infarction, while thrombolysis in myocardial infarction (TIMI) myocardial perfusion (TMP) grade ...

Lipomatous hypertrophy of the interatrial septum is a benign cardiac mass characterized by fat accumulation in the interatrial septum. Cardiac arrhythmias including atrial fibrillation, atrial premature contractions and atrioventricular block may occur as a consequence of involvement of the atrial wall and atrioventricular conduction pathways. We describe a patient with ...

OBJECTIVE: The aim of this study was to evaluate the impact of either left atrial or aortic spontaneous echocardiographic contrast (SEC), as identified on intraoperative transesophageal echocardiography, on short-term morbidity and mortality in patients with left atrial enlargement undergoing cardiac valvular surgery. DESIGN: Retrospective and observational. SETTING: Single-center, university teaching ...

OBJECTIVES: When extracorporeal membrane oxygenation (ECMO) is used in the setting of severe myocardial dysfunction, left ventricular end-diastolic and left atrial pressure can rise to extremely high levels. Decompression of the left atrium in this setting is essential for resolution of pulmonary edema and recovery of left ventricular function. We ...

Primary cardiac sarcoma is an uncommon disease. In particular, leiomyosarcoma of cardiovascular origin is extremely rare. Half of all cardiac leiomyosarcomas are located in the left atrium. Due to the extreme rarity of left atrial leiomyosarcoma, there is no great experience in its management. This review includes a report of ...

A 71-year-old woman with Turner's syndrome underwent pacemaker implantation for complete atrio-ventricular block. During the procedure, the persistence of left sided superior vena cava (LSVC) was observed such that the lead, through the coronary sinus, reached the right atrium. By use of stylets, we could drive the lead against the ...

Congenital cardiac malformations which include isomerism of the atrial appendages are amongst the most challenging of problems for diagnosis and also for medical and surgical management. The nomenclature for pathological description is controversial, but difficulties can be overcome by the use of a segmental approach. Such an approach sets out ...

OBJECTIVE: The number of transseptal punctures performed worldwide has increased exponentially with the development of ablation therapies for atrial arrhythmias. Safe access into the left atrium in these procedures is often complicated by abnormal anatomy. We assessed the potential of right atrial angiography to facilitate transseptal puncture for atrial ablation. ...

OBJECTIVE: We evaluated left atrial dimensions and function in high C-reactive protein (CRP) patients with paroxysmal atrial fibrillation. BACKGROUND: In patients with increased plasma levels of CRP left atrial dysfunction may enhance the occurrence of arrhythmias. METHODS: Two-dimensional and pulsed Doppler echocardiography, were performed in 20 consecutive patients with high ...

Atrial tachy-arrhythmias may give rise to mode switching or noise rate reversion in dual-chamber pacemakers. In case of high amplitude of the atrial electrogram during tachycardia, a paradoxical behavior of atrial sensitivity programming can be observed. Two patients with implanted dual-chamber pacemakers showed intermittent and complete loss of atrial sensing ...

BACKGROUND AND AIM OF THE STUDY: The study aim was to examine tissue expression of the adhesion molecules E-selectin and P-selectin on atrial, valvular and atrial myocardial blood vessel endothelium in patients with rheumatic mitral stenosis, and to investigate whether such expression was correlated with hemodynamics. METHODS: Thirteen patients (eight ...

BACKGROUND: Previous angiogenesis models use animal tissues such as the chicken chorioallantoic membrane (CAM) or the rabbit cornea. These models may not accurately reflect the mechanisms responsible for human angiogenesis. MATERIALS AND METHODS: We hypothesized that fragments of human myocardial tissue would develop an angiogenic response from the cut edges ...

OBJECTIVES: This study assessed the effects of carbenoxolone on human myocardial conduction and refractoriness. BACKGROUND: Carbenoxolone, an antipeptic ulcer drug, has been shown to reduce gap junctional coupling without affecting cellular ion channels. Gap junctions (GJ) are considered to be determinants of cardiac action potential propagation. The effects of GJ ...

A 15-month-old boy with atrial fibrillation was found to have gross cardiomegaly on a chest radiography; further evaluation by echocardiography showed a giant right atrial aneurysm which is in the form of a cyst like lesion. The patient underwent successful surgical reduction of the right atrium converting his heart rhythm ...

BACKGROUND: The left atrial appendage is a frequent source of thromboemboli in patients with atrial fibrillation. Exclusion of the left atrial appendage may reduce the risk of stroke in patients with atrial fibrillation. The atrial exclusion device, previously developed to perform left atrial appendage exclusion on a beating heart, was ...

We report a rare case of atrial tachycardia (AT) originating from the upper left atrial septum. Electroanatomic mapping of both atria demonstrated that the earliest atrial activation during AT occurred at the upper left atrial septum 26 msec before the onset of the P wave, followed by the mid-right atrial ...

A 17-year-old male with tachycardia-induced cardiomyopathy presented with persistent, drug-resistant atrial tachycardia (AT). An electrophysiological study suggested focal abnormal automaticity, and localized the AT origin to the left atrial appendage. Radiofrequency catheter ablation at the site of the earliest endocardial activation during AT failed. A minimally invasive, video-assisted thoracoscopic (VAT) ...

BACKGROUND: Radiofrequency energy delivered throughout the cardiac cycle has the potential to cause thermal injury to the esophagus if the anatomical relationship between the posterior left atrium and the esophagus changes during cardiac motion. OBJECTIVE: To assess the posterior left atrial-esophageal relationship throughout the cardiac cycle. METHODS: In this study, ...

It has been suggested that successful percutaneous balloon mitral valvuloplasty (PMV) decreases the intensity of spontaneous left atrial contrast, reduces the size of the left atrium, and improves left atrial function in patient with mitral stenosis. However, left atrial mechanical functions immediately after PMV have not been extensively evaluated yet. ...

BACKGROUND AND OBJECTIVES: The role of atrial myocardial dysfunction after cardioversion is unclear. In a comparison of patients after successful cardioversion from chronic atrial fibrillation (CAF) and normal controls, we sought to determine whether Doppler-derived atrial strain rate (A-sr) could be used to measure global left atrial function and whether ...

The cardiac conduction system (CCS) is responsible for generation and systematic conduction of cardiac impulses. The Bachmann Bundle (BB), considered one of its several accessory impulse-conducting pathways, plays a fundamental role in interatrial conduction. Delay in this pathway leads to prolongation of the P wave on the electrocardiogram (interatrial delay ...

Chronic atrial dilation is associated with atrial conduction velocity slowing and an increased risk of developing atrial tachyarrhythmias. Rotigaptide (ZP123) is a selective gap junction modifier that increases cardiac gap junctional intercellular communication. We hypothesised that rotigaptide treatment would increase atrial conduction velocity and reduce the inducibility to atrial tachyarrhythmias ...

BACKGROUND: Detailed right and left septal mapping of retrograde atrial activation during typical atrioventricular nodal reentrant tachycardia (AVNRT) has not been undertaken and may provide insight into the complex physiology of AVNRT, especially the anatomic localization of the fast and slow pathways. OBJECTIVES: The purpose of this study was to ...

Atrial flutter is a common arrhythmia that may cause significant symptoms, including palpitations, dyspnoea, chest pain and even syncope. Frequently, it is possible to diagnose atrial flutter with a 12-lead surface electrocardiogram (ECG), looking for distinctive waves in leads II, III, aVF, aVL, V1 and V2. Puech and Waldo developed ...

Atrial flutter is a relatively frequent macro-reentrant tachycardia that can be caused by a variety of structural and functional atrial changes. Cardiac lymphoma is rare and usually carries a poor prognosis. It preferentially involves the right atrium. This report describes a patient with cardiac follicular B-cell lymphoma who developed paroxysmal ...

OBJECTIVES: Certain congenital heart defects require the creation of an unrestrictive atrial septal defect (ASD) to relieve atrial hypertension, to maintain systemic cardiac output, or to achieve adequate atrial mixing to improve systemic oxygen saturation. We describe a series of patients, ranging in age from 5 weeks to 17 months, ...

Atrial standstill is a rare form of bradyarrhythmia and consists of a transitory or permanent loss of the electrical and mechanical activity of the atria. It has been described in a few cases of long-standing valvular disease, amyloidosis, myocarditis, and muscular dystrophy. We report on a young female with noncompaction ...

INTRODUCTION: Renin-angiotensin-aldosterone system activation may be involved in the pathogenesis of atrial arrhythmias in congestive heart failure (CHF). The effects of aldosterone blockade on atrial tachyarrhythmias have not been evaluated. This study's aim was to determine whether selective aldosterone blockade suppresses atrial tachyarrhythmia inducibility and modifies atrial electrical and/or structural ...

Electrocardiograms of a patient with transient auricular fibrillation and flutter and complete A-V heart block are presented. Further tracings, taken immediately after the resumption of normal sinus activity, show short paroxysms of what is believed to be impure flutter induced by normal sinus beats. Some experimental evidence tending to support ...

BACKGROUND: We previously characterized a novel K+ current (IKH) with properties of constitutively active acetylcholine-related current in dog atrium. I(KH) is sensitive to tertiapin-Q (IC50 approximately 10 nmol/L), a highly selective Kir3 current blocker. This study assessed the role of IKH in atrial tachycardia (AT)-remodeled canine left atrium (LA) with ...

BACKGROUND: Atrial arrhythmias are frequently observed in patients with heart failure and may be a primary cause for decompensation during cardiac resynchronization therapy (CRT). The accurate detection of organized atrial tachyarrhythmias poses a challenge to the function of mode-switching biventricular pacemakers/defibrillators. METHODS: The purpose of the study was to determine ...

Infants with hypoplastic left heart syndrome (HLHS) and restrictive or intact atrial septum (rAS) present with cyanosis, pulmonary edema, and are critically ill. A previous report from our institution on emergent Norwood for HLHS with rAS showed 10% survival. We hypothesized that transcatheter left atrial (LA) decompression in HLHS with ...