Walter Gaskell's demonstration in 1882 that it was possible to block the passage of contraction from auricle to ventricle in the frog heart by means of a clamp spurred Joseph Erlanger (1906) to prevent, by similar means, impulse conduction through the bundle of (Wilhelm) His jun. (1893) in the mammalian ...

Dissimilar electrocardiographic patterns associated with right bundle branch block have been described. The morphological diversity in right bundle branch block patterns is likely to be related to multiple factors-site of block, nature of defect (functional, necrosis, fibrosis), degree of conduction delay, and associated pathologies with their own ECG patterns. The ...

To identify genetic factors influencing cardiac conduction, we carried out a genome-wide association study of electrocardiographic time intervals in 6,543 Indian Asians. We identified association of a nonsynonymous SNP, rs6795970, in SCN10A (P = 2.8 x 10(-15)) with PR interval, a marker of cardiac atrioventricular conduction. Replication testing among 6,243 ...

Changing axis deviation has been reported during atrial fibrillation or atrial flutter. Changing axis deviation has also been reported during acute myocardial infarction associated with atrial fibrillation or at the end of atrial fibrillation during acute myocardial infarction. A left bundle branch block is usually associated with normal or left ...

A New Method to Evaluate Linear Block at the Left Atrial Roof. Objective: The present study aimed to evaluate a new method for validation of complete linear block at the left atrial (LA) roof. Background: Linear lesions at the LA roof have been reported to improve the success rate of ...

We report a case of a patient who developed repetitive episodes of polymorphic ventricular tachycardia with a stereotypical pattern of initiation. A premature atrial complex would result in a brief pause followed by left bundle branch block aberrancy. Ventricular bigeminy would ensue followed by episodes of polymorphic ventricular tachycardia, some ...

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or ...

The primary concern in patients with bifascicular block is the increased risk of progression to complete heart block. Further, an additional first-degree A-V block in patients with bifascicular block or LBBB might increase the risk of block progression. Anesthesia, monitoring and surgical techniques can induce conduction defects and bradyarrhythmias in ...

Pseudo 2:1 AV block when sinus intervals are shorter than the ventricular refractory period has been reported with long QT syndrome (LQTS). We report the characteristics and treatment of a patient suffering from congenital LQTS with episodes of true 2:1 AV block. The pseudo 2:1 AV block relates to the ...

Cardiac resynchronization therapy, which involves the placement of a pacing lead in the right atrium and in each ventricle, is effective in treating heart failure that is caused by left bundle branch block and cardiomyopathy. The left ventricular lead is usually placed into a lateral branch of the coronary sinus ...

We report a case of a patient with an implantable cardioverter defibrillator and no prior history of heart block with managed ventricular pacing (MVP) programmed who had frequent recurrent episodes of polymorphic ventricular tachycardia. All of the episodes were initiated by transient atrioventricular block which resulted in short-long-short sequences permitted ...

BACKGROUND: Right ventricular apical pacing may possibly induce atrial dilatation as a consequence of atrioventricular dyssynchrony. However, atrial enlargement associated with atrioventricular dyssynchrony due to atrioventricular block has never been studied. METHODS: This case-control survey involved 90 patients with symptomatic atrioventricular block [29 patients with Mobitz type 2 atrioventricular block, ...

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or ...

In a patient with atrial tachycardia with a rate of 200 per minute, the A-V conduction ratio was at times 2:1, but often it was 4:3 or 3:2 with progressive P-R interval prolongation (Wenckebach mechanism, an expression of presumable A-V nodal block). In each episode of 4:3 conduction, the first ...

A tachycardia with left bundle-branch block morphology and right axis deviation points to the diagnosis of ventricular tachycardia. Conversely, any supraventricular tachycardia with left bundle-branch block is typically associated with a normal or leftward QRS axis. We present the case of a 34-year-old man showing atrioventricular nodal reentrant tachycardia with ...

Concealed retrograde activation of bundle branch has been often proposed for explaining the persistence of functional rate-dependent bundle-branch block, but direct proof of such a mechanism in man has rarely been demonstrated. We report intracardiac recordings compatible with a reversal of activation of the left basal interventricular septum during intermittent ...

We present the case of a 72-year-old man who was admitted because of acute ST-segment elevation myocardial infarction and presented with second-degree atrioventricular block with 4:2 conduction. We propose 3 alternative explanations for such an unusual conduction pattern: (1) supernormal conduction, (2) 2-level block with 4:1 conduction ratio in the ...

Interatrial block (IAB) is defined as delayed conduction between the right and left atrium, which results in prolonged P-wave duration (> or =110 milliseconds). Interatrial block can be partial or advanced (much less common), depending on the severity of the conduction abnormality. Several studies have reported that the prevalence of ...

Isolated ventricular noncompaction (IVNC) is a primary cardiomyopathy characterized by a specific morphologic pattern. Patients with IVNC can develop various arrhythmic complications such as life-threatening ventricular arrhythmias, as well as heart failure or systemic embolic events. The present study was designed to comprehensively analyze the electrocardiographic (ECG) pattern at the ...

BACKGROUND: One of the most important aims of modern sports cardiology is prevention of sudden cardiac death among athletes. Adequate pre-participation screening is a crucial part of prevention, however, current ACC, AHA or ESC guidelines are not uniform in this context. There is recently ongoing discussion on implementation of 12-lead ...

Bundle branch block (BBB) is impossible to diagnose in a fetus with conventional fetal echocardiography. Isolated left BBB is rare in the neonatal period. Asymmetric left ventricular remodeling in isolated left BBB is secondary to chronic dyschronous activation and relaxation, resulting in thinning of the interventricular septum (IVS). This report ...

INTRODUCTION: Compared with anterior wall myocardial infarction, inferior wall myocardial infarction is generally regarded as being low risk. The aim of this study was to elucidate the clinical factors affecting its inhospital outcome. METHODS: From January 1997 to March 2006, 546 consecutive patients who suffered from their first inferior wall ...

Trastuzumab (Herceptin) is well documented in reducing suffering and mortality from breast cancer. The clinically most important side effect of Herceptin is cardiotoxicity, which is reported in 2.6% to 4.5% of patients receiving trastuzumab alone and in as many as 27% of patients when trastuzumab is combined with an anthracycline ...

Organophosphates and carbamate compounds are acetylcholinesterase inhibitors used as agricultural insecticides and represent a common cause of cholinergic toxicity. Cardiac manifestations of organophosphate and carbamate toxicity are described primarily from reports of organophosphate exposure and include sinus bradycardia, prolonged PR interval, sinus tachycardia, prolonged corrected QT interval and ventricular arrhythmias. ...

Paroxysmal atrioventricular block (AVB) is a poorly defined clinical entity characterized by abrupt and unexpected change from 1:1 atrioventricular conduction to complete heart block, leading to syncope and potential sudden cardiac death. Although a dangerous condition because of unreliable escape mechanism, proper diagnosis of paroxysmal AVB is often missed and ...

OBJECTIVES: To evaluate right bundle branch block (RBBB) on electrocardiograms (ECGs) as a screening tool for the diagnosis of pulmonary embolism (PE) in a chronic spinal cord injury (SCI) population and to determine the prevalence of PE. DESIGN: Retrospective analysis. SETTING: Boston Veterans Affairs Healthcare System. PARTICIPANTS: Consecutive SCI participants ...

Paroxysmal atrioventricular block has been reported in patients without acute coronary syndrome and without significant coronary artery stenosis, in patients with acute coronary syndrome and without significant coronary artery stenosis, in patients without acute coronary syndrome and with significant coronary artery stenosis and in patients with acute coronary syndrome and ...

We describe the case of a 73 year-old woman presenting with symptoms compatible with myocardial ischemia/injury and left bundle branch block in whom the electrocardiogram fulfilled Sgarbossa criteria for ST-elevation myocardial infarction. Coronary angiography revealed an acute coronary occlusion and she was successfully revascularized. The value and limitations of the ...

A chronic hypertensive patient with electrocardiogram (ECG) showing left bundle branch block (LBBB) was given general anesthesia for right modified radical mastectomy. Her ECG reverted to normal sinus rhythm intermittently during peri-operative period. This intermittent rate-dependent LBBB is a rare entity. Though hypertension is one significant co-morbid condition, the risk ...

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or ...

OBJECTIVE: To determine the influence of time on development of high degree Atrioventricular (AV) block in patients with inferior Myocardial Infarction (MI), its association with Right Ventricular (RV) infarction and its ultimate morbidity and mortality. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: The Emergency Department (ED) and ...

Intraventricular conduction abnormalities are commonly seen on the electrocardiograms of patients in the emergency department population. The significance of such a finding can vary widely. When placed into clinical context, determination and description of an intraventricular conduction delay (IVCD) can assist in the management of a number of pathologies--directly cardiac ...

Concealed conduction commonly occurs when a retrogradely conducted interpolated ectopic impulse enters the atrioventricular (AV) node; thus, the next sinus beat is not conducted to the ventricle or conducted with a prolonged PR interval because of increased refractoriness of AV conduction system. A 67-year-old man had complaints of exertional fatigue ...

BACKGROUND: Chagas disease is a serious social-medical problem in Latin American countries because of its high incidence, morbidity and mortality. Our aim was to identify, from demographic, personal history, clinical and electrocardiographic variables, those that might have independent prognostic value regarding mortality, among a population of chronic Chagas patients from ...

An innovative method was proposed on the basis of vectorcardiography to characterize the location and extent of moderate to large, relatively compact infarcts using ECG evidence. It is assumed that heart vector is proportional to relevant active depolarization area(s). The normal VCG was then used to examine our ideas based ...

A simple dissection guide for the conduction system of the human heart is shown. The atrioventricular (AV) node, AV bundle, and right bundle branch were identified in a formaldehyde-fixed human heart. The sinu-atrial (SA) node could not be found, but the region in which SA node was contained was identified ...

INTRODUCTION: Serious cardiac toxicity due to lithium toxicity is uncommon and generally only occurs in individuals with underlying heart disease. Cardiac impairment may result in dysrhythmias, including sinus bradycardia, sinoatrial block, and first-degree atrioventricular block. This paper describes a patient with complete AV block in the course of chronic lithium ...

Dissimilar electrocardiographic patterns associated with right bundle branch block have been described. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Changing bundle branch block, new right bundle branch block, right ...

OBJECTIVES: Endoscopic ultrasound (EUS)-guided celiac plexus block/neurolysis (CPB/N) can be performed by injecting at the base (central) or on either side (bilateral) of the celiac axis. Central CPB/N is easier and possibly safer. Bilateral CPB/N is more difficult but may be more effective as it reaches more ganglia. The aim ...

Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. ...

The aim of this study was to investigate the effects and mechanisms of intestinal electrical stimulation (IES) on gastric tone, antral and pyloric contractions, and gastric emptying in dogs. Female hound dogs were equipped with a duodenal or gastric cannula, and one pair of serosal electrodes was implanted in the ...

INTRODUCTION: Thyrotoxicosis is a clinical entity often very difficult to diagnose without biochemical confirmation as its clinical features can be highly varied. The most common cardiac manifestations of thyrotoxicosis are resting sinus tachycardia, supraventricular tachycardia including atrial fibrillation and atrial flutter with or without cardiac failure. Bradycardia and atrio-ventricular conduction ...

Reliable diagnosis of congenital heart defects and arrhythmias in utero has been possible since the introduction of fetal echocardiography. The nation-wide prenatal ultrasound screening program in the Czech Republic enabled detection of cardiac abnormalities in 1/3 of patients born with any congenital heart disease and up to 83 % of ...

It has been rarely reported changing axis deviation in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. It has also been rarely reported changing axis deviation with changing bundle branch block with onset of atrial fibrillation during acute myocardial infarction. We ...

Paroxysmal atrioventricular block is an ill-defined entity, previously described in sporadic cases in association with vasovagal reaction, coronary angiography and distal conduction disease. The occurrence of atrioventricular block in acute inferior wall myocardial infarction is related to the presence of an important right coronary artery that is occluded, the recanalisation ...

OBJECTIVE: Vertical plication of the atrialized chamber in Ebstein malformation has been subject to debate. A major argument against it is risk of coronary arterial injury; however, the coronary anatomy in the malformation remains incompletely investigated. METHODS: We examined 17 autopsied hearts with the malformation. Special attention was paid to ...

Duchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene on chromosome Xp21.1. It is characterized by progressive muscle wasting and weakness of variable distribution and severity. Heart is involved leading to heart failure. Conduction abnormalities are unusual. We report a case of complete ...

We have used zebrafish and 3,3',4,4',5-pentachlorobiphenyl (PCB126) to investigate the developmental toxicity of polychlorinated biphenyls (PCBs) that exert their effects through the aryl hydrocarbon receptor (AHR). We found that cardiac and neural crest (NC)-derived jaw and branchial cartilages are specifically targeted early in development. The suite of malformations, which ultimately ...

PURPOSE OF REVIEW: Evidence from retrospective studies suggests that regional anesthesia reduces the risks of major complications associated with carotid endarterectomy compared with general anesthesia, namely: stroke, stroke/death, death and myocardial infarction. RECENT FINDINGS: A superficial cervical plexus block is the regional anesthetic technique of choice. It is as efficacious ...

AIMS: To analyse QRS morphology in response to rapid atrial pacing (RAP) and supraventricular tachycardia (SVT) in patients with pre-existing bundle branch block (BBB). METHODS AND RESULTS: We prospectively studied 59 patients in sinus rhythm (SR), with QRS > or = 120 ms, and no pre-excitation. Trains of RAP were ...