Perimitral atrial flutter in cardiac allograft recipients is uncommon. In general, mitral isthmus ablation can be quite challenging in all patients with perimitral flutter, including the subset of patients who present following left atrial ablation for atrial fibrillation. We report 2 cases where an anterior ablation line was easily performed ...

INTRODUCTION: Accurate atrial arrhythmia discrimination is important for dual chamber pacemakers and defibrillators. The aim was to assess the accuracy of atrial arrhythmia recording using modern devices and relate this to atrial tip-to-ring (TTR) distance. METHODS: One hundred eighty-two patients (72 + or - 9 years, 55% male) with paroxysmal ...

Left atrial appendage aneurysm (LAAA) is a rare condition caused by congenital dysplasia of the atrial muscles. Patients usually present with atrial tachyarrhythmias as a result of ectopic foci of atrial rhythm generation or systemic thromboembolism. We report a case of a 38-year-old Native American female presenting with 1-month history ...

OBJECTIVE: Atrial fibrillation puts patients at significant risk for embolic stroke originating from the left atrial appendage. Few means are available for safe, effective, and durable left atrial appendage occlusion. A new clip device was evaluated with regard to safety and effectiveness for epicardial left atrial appendage occlusion. METHODS: Patients ...

Aorto-right atrial tunnel (ARAT) is a rare clinical entity. Although it is a benign finding in most cases; it can present with significant right ventricular volume overload and congestive heart failure. This report describes the first fetal diagnosis of congenital aorto-right atrial tunnel and successful management of the heart failure ...

This paper describes an unsupervised signal processing method applied to three-channel unipolar electrograms recorded from human atria. These were obtained by epicardial wires sutured on the right and left atria after coronary artery bypass surgery. Atrial (A) and ventricular (V) activations had to be detected and identified on each channel, ...

Myocardial adrenergic receptors (ARs) play important roles in cardiac hypertrophy. However, the detailed molecular mechanism of AR-mediated cardiac hypertrophy remains elusive to date. To gain full insight into how ARs are involved in the regulation of cardiac hypertrophy, protein expression profiling was performed with comparative proteomics approach on neonatal rat ...

We describe the management of a patient who presented with symptoms of severe congestive heart failure. A 48-year-old man was initially seen in the emergency room, admitted to the hospital, and worked up with a transthoracic echocardiogram, a transesophageal echocardiogram, and a computer tomography scan of the chest. All cardiac ...

OBJECTIVES: The aim of this study was to evaluate atrial electromechanical delay measured by tissue Doppler imaging (TDI) and left atrial (LA) mechanical functions in patients with rheumatoid arthritis (RA). STUDY DESIGN: The study included 68 patients (53 females, 15 males; mean age 43.7 years) with RA. Using TDI, atrial ...

Atrial standstill is characterized by failure of atrial excitation, either spontaneous or induced by atrial electric stimulation. We report the case of a 38-year-old man with severe bradycardia and junctional escape rhythm associated with dilative cardiomyopathy. Electroanatomic mapping showed the absence of atrial viability in almost the entire right atrial ...

In contrast to extensive reports on the roles of Na(v)1.5 alpha-subunits, there have been few studies associating the beta-subunits with cardiac arrhythmogenesis. We investigated the sino-atrial and conduction properties in the hearts of Scn3b(-/-) mice. The following properties were compared in the hearts of wild-type (WT) and Scn3b(-/-) mice: (1) ...

BACKGROUND: Multisite atrial pacing (MAP) was introduced to improve atrial electrical synchrony and prevent recurrence of atrial fibrillation (AF). METHODS AND RESULTS: In the present study there were 57 patients with sinus node disease, AF recurrence and prolonged P-wave on ECG with 2 MAP modalities. In all patients 1 lead ...

The purpose of this study is to describe the prevalence, morphology, size, and location of left atrial abnormalities including diverticula and accessory appendages in consecutive patients undergoing cardiac-gated CT for coronary artery evaluation. Routine retrospectively gated contrast-enhanced 64-MDCT angiography (0.75-mm collimation, 330-milliseconds gantry rotation time) was performed in 529 consecutive ...

After atrial fibrillation, atrial flutter (AFL) is the most important and most common atrial tachyarrhythmia. Atrial flutter describes an electrocardiographic model of atrial tachycardia >or=240/min, with a uniform and regular continuous wave-form. There is classically a 2:1 conduction across the atrioventricular (AV) node; as a result, the ventricular rate is ...

The effects of ibutilide on non-isthmus-dependent atrial flutter (NIDAFL) and the left atrium are not completely known. We describe a case report of 2:1 left to right interatrial block as a result of ibutilide during NIDAFL. This is a 68-year-old man with history of right atrial flutter ablation who presented ...

A 64-year-old man with complete heart block, status post-Medtronic dual chamber pacemaker insertion, failed ablation for atrial tachycardia at an outside institution. Despite persistent palpitations and known unsuccessful ablation, pacemaker interrogation revealed no evidence of atrial arrhythmias. At electrophysiology study, burst pacing from the high right atrium and distal coronary ...

A 19-year-old man suffered a cardiac arrest during a promenade with his friends. Cardiac resuscitation was started immediately. Anamnesis uncovered that the father as well as a cousin of the patient suffered from myotonic dystrophy (MD). Follow-up ECG monitoring showed intercurrent III degree AV-block as well as several asymptomatic episodes ...

OBJECTIVES: There are some clinical and echocardiographic parameters to predict paroxysmal atrial fibrillation (PAF), but more sensitive predictors are needed. Tissue Doppler imaging may be a sensitive method for this purpose. METHODS: Thirty-four patients with PAF and 31 control subjects were studied. Time intervals from the beginning of P-wave to ...

The left atrial appendage (LAA) is a cardiac structure with unique anatomic and functional features. It is significantly more than a simple chamber appended to the left atrium (LA), differing from the LA in structure, function, and hormonal activity. Unfortunately, it is the source of more than 90% of cardiac-based ...

We present a patient with paroxysmal, non-sustained atrial tachycardia (AT) on routine surveillance 24-hour Holter post pulmonary vein isolation (PVI). Several asymptomatic ventricular pauses are noted to follow each burst of AT. We postulate that these pauses are due to the resultant concealed penetration of the atrio-ventricular node (AVN) in ...

Changes in patients' autonomic tone and specific pharmacologic interventions may modify the ventricular response (actual heart rate) during atrial fibrillation (AF). Hypnotic agents such as propofol may modify autonomic balance as they promote a sedative state. It has been shown that propofol slightly slows atrial fibrillatory activity, but the net ...

The cardiac conduction system (CCS), consisting of the sino-atrial node, atrioventricular node and His-Purkinje system, is responsible for the initiation and co-ordination of the heart beat. In the last decade, our understanding of the CCS has been transformed. Immunohistochemistry, used in conjunction with anatomical techniques, has transformed our understanding of ...

To study atrial tachycardia-induced electrical remodeling in a canine model of sinus node dysfunction (SND). A canine model of SND was established by contacting a cotton patch with 20% formaldehyde on the sinus node. Atrial effective refractory period (ERP), ERP dispersion, and inducibility of atrial fibrillation (AF) were recorded at ...

Nicorandil has protective effects on the ischemic atrial myocardium. However, effects of nicorandil on ischemia-induced impulse conduction disturbances are still uncertain. Optical action potentials were recorded from 256 sites of the left atrium in isolated arterially perfused canine atria during the left atrial ischemia. Constant pacing (BCL = 350 ms) ...

Sonic hedgehog (Shh) is a secreted morphogen necessary for the production of sidedness in the developing embryo. In this study, we describe the morphology of the atrial chambers and atrioventricular junctions of the Shh null mouse heart. We demonstrate that the essential phenotypic feature is isomerism of the left atrial ...

We present a 57-year old male patient with thalassemia intermedia and right heart failure. He had a 30-year history of anemia and short-term iron therapy without blood transfusion. Hemoglobin level was 7.1 g/dl and hematocrit was 22.7%. White blood-cell and platelet counts, and serum ferritin level were normal. Electrocardiography showed ...

The aim of the present study was to verify the validity of two-dimensional echocardiographic (2DE) measurement technique in dogs with left atrial enlargement. Thirty-one dogs with clinically and echocardiographically proven cardiac diseases were randomly selected. The left atrial right-to-left diameter (La(r-l)) and the diameter of the left atrium just above ...

While ventricular gap junctions contain only Cx43, atrial gap junctions contain both Cx40 and Cx43; yet the functional consequences of this co-expression remain poorly understood. We quantitated the expression of Cx40 and Cx43 and their contributions to atrial gap junctional conductance (g(j)). Neonatal murine atrial myocytes showed similar abundances of ...

A 74-year-old woman was at the emergency department for acute chest pain, dyspnea and severe transient hypotension. History was arterial hypertension and external electrical cardioversion (EEC) for persistent atrial fibrillation (AF) 8 days before admission. At that time echocardiography was normal. The patient underwent coronary angiography with no evidence of ...

AIMS: Assessment of left and right systolic atrial reservoir function in asymptomatic mitral stenosis (MS) by strain and strain rate imaging (SRI) and their prognostic power at 3 year follow-up was the purpose of this study. There is clear indication to treat (by surgery or percutaneous valvotomy) symptomatic patients with ...

Focal atrial tachycardia is a relatively uncommon arrhythmia. Nevertheless, the management of highly symptomatic patients with focal atrial tachycardia can be problematic owing to the poor response to medical treatment. Moreover, focal atrial tachycardia can trigger other atrial arrhythmias like atrial fibrillation and flutter. Radiofrequency ablation of focal atrial tachycardia ...

A patient with atrial tachycardia presented with dyspnoea on exertion. Transoesophageal echocardiography revealed idiopathic left atrial appendage stenosis. The mouth of the atrial appendage was narrowed, and there was a high velocity to and fro jet between the left atrial body and the left atrial appendage. The study, therefore, suggested ...

BACKGROUND: The left atrium is a validated marker of clinical and subclinical cardiovascular disease. Left atrial enlargement is often seen among older individuals; however, there are few population-based data regarding normal left atrial size among older persons, especially from those who are healthy, and from women. Furthermore, because the left ...

Interatrial block (IAB; P duration >or=110 ms) is a common electrocardiogram abnormality, which in addition to reduced left atrial function predicts atrial fibrillation and other arrhythmias. P terminal force (Ptf) +/- biphasic P in lead V(1)>or= the area of one small square on the grid also indicates left atrial abnormality, ...

BACKGROUND: Cardiac disease is the most common cause of death in patients with end-stage renal disease. It is assumed that the high rate of cardiovascular mortality is related to accelerated atherosclerosis. Patients with chronic renal insufficiency have an increased prevalence of coronary artery disease, silent myocardial ischaemia, complex ventricular arrhythmias, ...

To determine the clinical efficacy of application of infrared energy to the beating heart as a means of creating electrical blocks, an original infrared coagulator (KIRC-119; Phomec Inc, Tokyo, Japan) was applied to the atrium of a patient with atrial fibrillation. A postoperative electrophysiologic study was performed to confirm its ...

The genesis of the septal structures of the mammalian heart is central to understanding the ontogeny of congenital heart disease and the evolution of cardiac organogenesis. We found that Hedgehog (Hh) signaling marked a subset of cardiac progenitors specific to the atrial septum and the pulmonary trunk in the mouse. ...

AIM: Slow coronary flow (SCF) is characterized by angiographically normal coronary arteries with delayed opacification of the distal vasculature. The purpose of this study was to evaluate atrial electromechanical couplings and P-wave dispersion (Pd) reflecting intraatrial and interatrial conduction delays in SCF patients and the relationship between these parameters and ...

Rhythm disturbances have been described in immunological and connective diseases. Scleroderma is a fibrotic condition characterized by immunological abnormalities, vascular injury and increased accumulation of extracellular matrix proteins. The heart is one of the major organs involved in scleroderma, the involvement of which can be manifested by myocardial disease, conduction ...

BACKGROUND AND HYPOTHESIS: Interatrial block (IAB: P-duration > 100 ms) is poorly recognized in hospital populations. In addition to reduced left atrial function and left atrial enlargement it predicts atrial fibrillation and other arrthymias. P-terminal force (Ptf): +/- biphasic P in lead V(1) > or = area of 1 small ...

The aim of this study was to assess the release of endothelium-derived relaxing factors from the endocardium of canine atrial appendage. To study the release of endothelium-derived relaxing factor (EDRF) from intact atrial endocardial endothelium, tube-shaped sutures of canine atrial appendages were performed and effluents from these tubes were bioassayed ...

We report the case of a patient with atrial flutter late after tricuspid valve replacement for Ebstein's anomaly. Computed tomographic angiography revealed that coronary sinus ostium and part of the right atrial isthmus were located on the ventricular side of the valve ring due to the specific surgical approach in ...

The left atrial posterior wall (LAPW) plays a critical role in atrial fibrillation, but the underlying mechanism remains unclear. In the present study, we sought to characterize the histological features of the LAPW. Different atrial regions were dissected from hearts of normal Sprague-Dawley rats and humans. Haematoxylin/eosin and van Gieson ...

Learning embryology remains difficult, since it requires understanding of many complex phenomena. The temporal evolution of developmental events has classically been illustrated using cartoons, which create difficulty in linking spatial and temporal aspects, such correlation being the keystone of descriptive embryology. We synthesized the bibliographic data from recent studies of ...

BACKGROUND/OBJECTIVE: The purpose of this study was to clarify the spatial relationship between the left phrenic nerve (LPN) and key cardiac structures in order to minimize the risk of phrenic nerve injury during interventions. METHODS: The course and relationship of the LPN to various cardiac structures were examined by gross ...

Atrial thrombosis is a relatively rare event in children. We report a case of a newborn with AFI who after restoration of sinus rhythm, developed atrial thrombus on a prominent Chiari network floating between the right and left atrium through the patent foramen ovale. The thrombus was resolved following treatment ...

Obstructive sleep apnea (OSA) is associated with increased risk for the occurrence and recurrence of atrial fibrillation. However, the mechanisms involved are poorly understood. We studied 73 middle-aged subjects divided in two groups: with moderate-to-severe OSA (apnea-hypopnea index [AHI] ≥ 15 events/h) or without OSA (AHI ≤5 events/h) by polysomnography. ...

OBJECTIVE: The objective was to study atrial activation intervals and their relation to the tachycardia cycle length (TCL) as electrophysiologic parameters differentiating focal (FAT) from macroreentrant atrial tachycardias (MRAT) originating in the right atrium. METHODS: In 21 patients (8 men) with 30 successfully ablated right atrial tachycardias (15 focal) the ...

Typical atrial flutter (AFL) is a common atrial arrhythmia that may cause significant symptoms and serious adverse effects including embolic stroke, myocardial ischemia and infarction, and rarely a tachycardia-induced cardiomyopathy as a result of rapid atrioventricular conduction. As a result of the well-defined anatomic and electrophysiological substrate, and the relative ...

The analysis of atrial fibrillation in non-invasive ECG recordings has received considerable attention in recent years, spurring the development of signal processing techniques for more advanced characterization of the atrial waveforms than previously available. The present paper gives an overview of different approaches to the extraction of atrial activity in ...