Search results for "Right atrium"

Effect of intravenous flecainide on atrial vulnerability in man.

1983

Sixteen patients were investigated by means of programmed atrial stimulation at two different driving rates: 100 and 120/min. All patients had an increased atrial vulnerability at both driving rates. After intravenous flecainide application (1 mg/kg body weight as a bolus followed by the same amount given by infusion over a period of 20 min) the increased vulnerability was abolished in 11 and 9 patients respectively. In the remaining patients the rate of induced atrial tachyarrhythmia decreased. These findings correlate with a significant prolongation of the effective refractory period of the right atrium and a significant shortening of the relative refractory period of the right atrium. It…

Wave similarity mapping shows the spatiotemporal distribution of fibrillatory wave complexity in the human right atrium during paroxysmal and chronic…

2005

Introduction: The complexity of waveforms during atrial fibrillation may reflect critical activation patterns for the arrhythmia perpetuation. In this study, we introduce a novel concept of map, based on the analysis of the wave morphology, which gives a direct evidence in the human right atrium on the spatiotemporal distribution of fibrillatory wave complexity in paroxysmal (PAF) and chronic (CAF) atrial fibrillation. Methods and Results: Electrograms were recorded from a 64-electrode catheter in the right atrium of 15 patients during PAF (n = 8) and CAF (n = 7). Wave similarity maps were constructed by calculating the degree of morphological similarity of activation waves (S) at each atri…

Implantation Strategy of the Atrial Dipole Impacts Atrial Sensing Performance of Single Lead VDD Pacemakers

2002

WIEGAND, U.K.H., et al.: Implantation Strategy of the Atrial Dipole Impacts Atrial Sensing Perfor-mance of Single Lead VDD Pacemakers. Intermittent atrial undersensing is observed in a considerable percentage of patients with single lead VDD pacemakers. Analyzing the 2-year data of the Saphir Multicenter Follow-Up Study, the authors investigated predictors for the occurrence of undersensing. The study included 194 patients with high degree AV block who received a VDD pacemaker system with an identical sensing amplifier. Placement strategy of the atrial dipole was left to the discretion of the implanting physician. At the final position, atrial potential amplitudes were measured during deep …

Right atrium compression by a renal cyst: a tomographic diagnosis.

2011

Correlation between atrial fibrillation driver locations and complex fractionated atrial electrograms in patients with persistent atrial fibrillation.

2018

Introduction The aim of this study was to evaluate a spatial correlation between active atrial fibrillation (AF) drivers measured by electrocardiographic imaging and complex fractionated atrial electrograms (CFAEs) in patients with persistent AF. Methods Sixteen patients with persistent AF were included. A biatrial geometry relative to an array of 252-body-surface-electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms were signal-processed (ECVUE™, CardioInsight Technologies Inc., Cleveland, OH, USA) to identify AF drivers. Before driver ablation, a biatrial mapping using the NavX system (St. Jude Medical, St. Paul, MN, USA) was perfo…

Nachweis von Markembolien wÄhrend Oberschenkelmarknagelungen mittels transösophagealer Echokardiographie

1989

Kardiopulmonale Komplikationen nach Marknagelosteosynthesen, insbesondere am Oberschenkel, sind bekannt. WAhrend der Nagelung einer Oberschenkelquerfraktur mit einem, geschlossenen distalen Fragment konnten durch transsophageale Echokardiographie im rechten Herzen durchstromende echogene Partikel nachgewiesen werden. Das intrakardiale Auftreten dieser Partikel stand in engem zeitlichen Zusammenhang mit dem Aufbohren der femoralen Markhohle und kann als Nachweis verschleppter Marksubstanz gedeutet werden. Die intraoperative Echokardiographie bietet sich an, Untersuchungen uber die Pathophysiologie kardiopulmonaler VerAnderungen nach Marknagel osteosynthesen durchzufuhren und die EffektivitAt…

Die Verteilung von Noradrenalin und Adrenalin im Herzen der Katze, des Kaninchens und der Ratte

1958

The concentration of noradrenaline in different parts of the heart was estimated in cats, rabbits, and rats. In each heart, the concentration of noradrenaline was much higher in the right atrium than in the left atrium and higher in the right ventricle than in the left one.

Quantification of synchronization during atrial fibrillation by Shannon entropy: Validation in patients and computer model of atrial arrhythmias

2005

Atrial fibrillation (AF), a cardiac arrhythmia classically described as completely desynchronized, is now known to show a certain amount of synchronized electrical activity. In the present work a new method for quantifying the level of synchronization of the electrical activity recorded in pairs of atrial sites during atrial fibrillation is presented. A synchronization index (Sy) was defined by quantifying the degree of complexity of the distribution of the time delays between sites by Shannon entropy estimation. The capability of Sy to discriminate different AF types in patients was assessed on a database of 60 pairs of endocardial recordings from a multipolar basket catheter. The analysis…

Determination of Synchronization of Electrical Activity in the Heart by Shannon Entropy Measure

2005

In this paper we propose a new index of synchronization for the study of heart’s electrical activity during atrial fibrillation (AF). The index relies on the measure of the time delays between correspondent activations in two atrial electrograms and on the characterization of their dispersion by a measure of Shannon Entropy. The algorithm was validated on simulated signals mimicking different degree of synchronization. Results showed the index was able to discriminate among different levels of organization, provided that it works on series of at least 50 activations (time resolution of almost 10 sec during AF). Moreover, we applied the algorithm to real bipolar electrograms, obtained from a…

Giant right atrial myxoma: A rare cause of cardiovascular collapse

2019

We report the case of a patient with a giant right atrial myxoma that remained clinically silent until it almost completely obliterated the right atrium, prolapsed into the right ventricle and obstructed the tricuspid valve inflow. This case illustrates the importance of rapid surgical intervention in the setting of acute heart failure caused by tumor masses obliterating heart valves or cardiac chambers.