Change of the retrograde atrial activation sequence during radiofrequency (RF) ablation of left-side accessory pathway can be due to another accessory pathway, another mechanism for the tachycardia, or due to intraatrial conduction block, partial or complete, caused by RF delivery to a site ...
PubMed
We report a patient with concealed Wolff-Parkinson-White syndrome who, following catheter ablation, demonstrated phase-3 and phase-4 retrograde block in a concealed accessory pathway. After an initial 'apparently successful' ablation, retrograde conduction was through the atrioventricular node during constant ventricular pacing. ...
Histopathologically, accessory atrioventricular (AV) pathways comprise tiny strands of working myocardium that traverse the AV groove and link between the atrial and ventricular myocardium. Antegrade and retrograde conduction in bidirectional accessory pathways have generally been considered to ...
Congenital coronary sinus anomalies are unusual and they rarely coexist with accessory atrio-ventricular pathways. These anomalies are generally symptomatic; however they can cause difficulty in mapping. The association between accessory pathway and coronary sinus anomalies may suggest an embryological link. Here, ...
Adenosine is routinely used during ventricular pacing to exclude the persistence of retrograde accessory pathways conduction after radiofrequency (RF) ablation procedures by blocking conduction over the atrioventricular node. This is the first report of an adenosine-dependent concealed ...
Fatigue phenomenon is transient failure of conduction following a period of repetitive excitation. Fatigue in accessory pathways is uncommon, and its electrophysiologic characteristics and clinical implications are unknown. Among the 215 patients who underwent electrophysiology studies from July 1992 to December 1993, 4 (2%) were found ...
Electrophysiologic intracardiac and noninvasive transesophageal testing, used to evaluate parameters of anterograde conduction across the accessory pathway, the refractory period and shortest atrial cycle length with 1:1 conduction over the pathway, were compared to assess the reliability of ...
A 16-year-old female patient with Wolff-Parkinson-White syndrome and supraventricular tachycardia underwent radiofrequency (RF) catheter ablation of an accessory pathway in the left lateral area. During RF ablation she developed reversible ST segment elevation secondary to coronary artery spasm. Coronary angiography demonstrated the ablation catheter in ...
Sixty-one patients underwent operation for supraventricular tachycardia: 52 had tachycardia associated with the atrioventricular accessory pathways; 9 patients had other forms of tachycardia. Accessory pathways were successfully divided in 92.3% of the patients. Classic endocardial approach was used in 30 patients; ...
Accessory pathway (AP) ablation is one of the most satisfying invasive electrophysiology procedures associated with high success rates and relatively few complications. Nevertheless, when APs are found on the cardiac septum, ablative procedures become complex, and unique pitfalls need to be avoided.These difficulties with septal ablation are magnified in ...
PubMed Central
Ventricular preexcitation, a feature of Wolff-Parkinson-White syndrome, is caused by accessory myocardial pathways that bypass the annulus fibrosus. This condition increases the risk of atrioventricular tachycardia and, in the presence of atrial fibrillation, sudden death. The developmental mechanisms underlying accessory ...
A study during the era of surgical ablation suggested that atrioventricular (AV) nodal conduction is faster in patients with accessory pathways than in controls. In the present study, AV nodal characteristics were studied in 30 patients who underwent radiofrequency ablation of an accessory ...
Background- The response to right ventricular (RV) entrainment is useful to distinguish atypical AV node reentrant tachycardia from AV reentrant tachycardia using a septal accessory pathway. Whether entrainment can differentiate between AV node reentrant tachycardia and AV reentrant tachycardia in patients with long-RP tachycardia has not been ...
In the normal heart, an insulating barrier separates the atria and ventricles. The only way in which electrical impulses can cross this barrier is via the atrioventricular (AV) node, which delays impulse conduction to ensure the forward flow of the blood. However, in some individuals, additional muscular bundles (accessory pathways) ...
We present the case of a 25 year-old man referred for an electrophysiological study due to suspected pre-excitation as the cause of two recent syncopal episodes. The admission electrocardiogram (ECG) showed a borderline PR interval of 120 ms and apparently small delta waves visible in leads V2-V4. Intracardiac recordings showed a short HV interval of 18 ms that was stable despite decremental ...
In Wolff-Parkinson-White Syndrome (WPW), presence of accessory pathways causes various tachyarrhythmias that lead to different symptoms and clinical conditions in patients. Atrial fibrillation is observed in about 20-30% of this group of patients. Life threatening malignant ventricular arrhythmias and sudden cardiac deaths are observed in patients having ...
... the 2 lower chambers are the right and left ventricles. The heart also has an electric system that ... the upper chambers of the heart called atrial fibrillation. If a patient with an accessory pathway develops ...
MedlinePLUS
It was long believed that Mahaim pathways represented nodo-fascicular or nodo-ventricular connections. However, this misconception was challenged when patients underwent surgical or catheter ablation of the AV node but remained pre-excited. Electrophysiology (EP) studies showed these pathways to be right sided decrementally conducting ...
Ventricular preexcitation, which characterizes Wolff-Parkinson-White syndrome, is caused by the presence of accessory pathways that can rapidly conduct electrical impulses from atria to ventricles, without the intrinsic delay characteristic of the atrioventricular (AV) node. Preexcitation is associated with an increased risk of ...
Wolff-Parkinson-White (WPW) syndrome is one of the pre-excitation syndromes in which activation of an accessory atrioventricular (AV) conduction pathway leads to bypass the AV node and cause earlier ventricular activation than the normal pathway. We report a patient with intermittent WPW syndrome who repeatedly ...
A 41-year-old woman with recurrent wide-QRS tachycardia is reported. Electrophysiologic findings were consistent with the diagnosis of a preexcited atrioventricular nodal reentrant tachycardia due to a bystander nodo-ventricular fiber. However, slow pathway ablation did not preclude tachycardia recurrence. A second electrophysiology study shed light on the correct mechanism ...
Sudden death might complicate the follow-up of symptomatic patients with the Wolff-Parkinson-White syndrome (WPW) and might be the first event in patients with asymptomatic WPW. The risk of sudden death is increased in some clinical situations. Generally, the noninvasive studies are unable to predict the risk of sudden death correctly . The electrophysiological study is the best means to detect ...
BACKGROUND--Reentrant tachycardias associated with Mahaim pathways are rare but potentially troublesome. Various electrophysiological substrates have been postulated and catheter ablation at several sites has been described. OBJECTIVE--To assess the efficacy and feasibility of targeting discrete Mahaim potentials recorded on the tricuspid annulus for the delivery of ...
In patients with chronic Chagas' cardiomyopathy, there are forms of the disease that affect the electrical conduction system almost exclusively. The most common disorders include right bundle branch block alone or in association with left anterior fascicular block. We present an unusual case of a patient with Chagas' cardiomyopathy in association with a preexcitation syndrome. ...
Stress thallium-201 myocardial perfusion imaging was performed in a patient with Wolff-Parkinson-White syndrome. Reverse redistribution phenomenon was observed in the absence of coronary artery disease. This seems to be the first report of normalization of this phenomenon in association with reversion of accessory pathway to normal atrioventricular ...
Energy Citations Database
OBJECTIVE--To compare two new power sources for catheter ablation in patients with the Wolff-Parkinson-White syndrome. DESIGN--120 consecutive patients with accessory pathways had catheter ablation. Low energy direct current (DC) was used in the first 60 patients and radio-frequency current in the next 60 patients. SETTING--Electrophysiological laboratory ...
We report the case of a patient with heterotaxy syndrome including complex single ventricular morphology and interrupted IVC in association with twin conduction systems and a nodoventricular accessory pathway connection. The presence of 3 distinct QRS morphologies was inadvertently discovered during a hemodynamic catheterization study ...
Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective ...
This short communication describes two normal variants of the accessory hemiazygous vein in a 15-year-old female. The article demonstrates that knowledge of the aberrant venous anatomy and the collateral pathway is important for the practising radiologist. PMID:21697414
We present the ECG with broad QRS complex tachycardia and left bundle branch block (LBBB) morphology. There are negative P waves in inferior leads (II, III, aVF) and positive in V1 with the RP interval of 124-164 ms. The slow-slow atrioventricular nodal reentrant tachycardia (AVNRT) conducted with LBBB aberrancy was diagnosed. The differential diagnosis of slow-slow AVNRT from ...
The purpose of this study was to determine if the electrophysiologic properties and the anatomic location of manifest accessory pathways affect the local electrogram intervals recorded at sites of successful radiofrequency ablation. Accessory pathways in 149 consecutive patients were categorized according to their ...
Transvenous catheter ablation techniques have recently been used successfully in blocking posteroseptal accessory pathways in patients with Wolff-Parkinson-White syndrome (WPWS). We report the case of a patient in the People's Republic of China who had WPWS and posteroseptal and right anterolateral accessory ...
Ventricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only ...
We present a case of WPW syndrome with an accessory pathway in the right free wall. Two prolonged and failed attempts at radiofrequency catheter ablation of this accessory pathway in other institutions led to a third attempt in our hospital. With a 7F catheter in the right coronary artery, transient ischemia in the ...
... kinase C activation by phorbol myristate acetate (PMA) results in T-cell proliferation that is independent of both accessory cells and activation of the ...
DTIC Science & Technology
...accessories consists of tubing, pumps, pressure monitors, air foam or bubble detectors, and alarms to keep blood moving...consists of mechanisms that monitor and control the temperature, conductivity, flow rate, and pressure of the dialysate and...
Code of Federal Regulations, 2011
and by the bone-conduction pathway. The air-conducted sound can be monitored and transformed appropriately by the interface, but the bone-conduction pathway ...
NASA Website
SummaryThe export of proteins from their site of synthesis in the cytoplasm across the inner membrane is an important aspect of bacterial physiology. Because the location of extracytoplasmic proteins is ideal for host-pathogen interactions, protein export is also important to bacterial virulence. In bacteria there are conserved protein export systems that are responsible for the majority of ...
A case with congenitally corrected transposition of the great arteries associated with the pre-excitation syndrome is presented. A gated-blood-pool study and Tl-201 myocardial imaging were performed using SPECT. The tomographic gated-blood-pool images showed the shapes of the right ventricle (RV) and left ventricle (LV), i.e., anatomically LV and RV respectively, to be reversed from that of normal ...
