Left and Right Atrial Contribution to the P-wave in Realistic Computational Models

2015 ◽  
pp. 439-447 ◽  
Author(s):  
Axel Loewe ◽  
Martin W. Krueger ◽  
Pyotr G. Platonov ◽  
Fredrik Holmqvist ◽  
Olaf Dössel ◽  
...  
Keyword(s):  
Computational Models ◽  
P Wave ◽  
Right Atrial ◽  
Left And Right ◽  
Atrial Contribution

High-frequency atrial electrical activity

1961 ◽  
Vol 16 (2) ◽  
pp. 300-304 ◽  
Author(s):  
Cesar A. Caceres ◽  
George A. Kelser ◽  
Juan Calatayud
Keyword(s):  
High Frequency ◽  
Electrical Potential ◽  
P Wave ◽  
Right Atrial ◽  
High Frequencies ◽  
Pr Interval ◽  
Frequency Components ◽  
Left And Right ◽  
Electronic Filters ◽  
High Frequency Content

Left and right atrial intracavitary and conventional surface leads were used to study electrocardiographic activity during the PR interval. Electronic filters were employed for analysis of wave frequency and harmonic content from 1.7 to 1700 cps. Amplifiers permitting standardization sensitivity to 500 mm/mv were used to obtain oscilloscopic tracings recorded at a paper speed of 75 mm/sec. Frequency analysis of the electrical potential recorded during P wave inscription demonstrated the presence of high-frequency content that is excluded by conventional electrocardiographic amplifiers. The high-frequency components are associated with the time of inscription of the electrocardiographic intrinsic deflection and have a relationship to the characteristics of the pressure-pulse curve. These relationships suggest that intracavitary high frequencies and the electrocardiographic intrinsic deflection originate from electrical discharges associated with initiation of contractile events. Submitted on June 6, 1960

Prenatal ultrasound diagnosis of pulmonary atresia in combination with left atrial isomerism

2017 ◽  
Author(s):  
M Medvedev, M.V. Kubrina, O.S. Zarubina et all
Keyword(s):  
Left Atrial ◽  
Reverse Flow ◽  
Ductus Arteriosus ◽  
Pulmonary Atresia ◽  
Prenatal Ultrasound ◽  
Ultrasound Diagnosis ◽  
Right Atrial ◽  
Second Trimester ◽  
Left And Right ◽  
Atrial Isomerism

Two cases of prenatal ultrasound diagnosis of left atrial isomerism in the second trimester of gestation is presented. These two cases were in combination with pulmonary atresia and right aortic arch. Left atrial isomerism was identify by the digit-like shape of the left and right atrial appendages. The pulmonary atresia was identified on the basis of reverse flow in small pulmonary artery. A right aortic was identified by “U”-shaped confluence of aorta and ductus arteriosus in view of three vessels and trachea. The trachea was located between the vessels. The pregnancies were terminated and prenatal diagnosis was conformed at autopsy

scholarly journals Inducibility, but not stability, of atrial fibrillation is increased by NOX2 overexpression in mice

2021 ◽  
Author(s):  
Alexandra S Mighiu ◽  
Alice Recalde ◽  
Klemen Ziberna ◽  
Ricardo Carnicer ◽  
Jakub Tomek ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Superoxide Production ◽  
Right Atrial ◽  
Burst Stimulation ◽  
Lv Mass ◽  
Surface Ecg ◽  
Tissue Homogenates ◽  
Genotype Difference ◽  
Left And Right

Abstract Aims Gp91-containing NADPH oxidases (NOX2) are a significant source of myocardial superoxide production. An increase in NOX2 activity accompanies atrial fibrillation (AF) induction and electrical remodelling in animal models and predicts incident AF in humans; however, a direct causal role for NOX2 in AF has not been demonstrated. Accordingly, we investigated whether myocardial NOX2 overexpression in mice (NOX2-Tg) is sufficient to generate a favourable substrate for AF and further assessed the effects of atorvastatin, an inhibitor of NOX2, on atrial superoxide production and AF susceptibility. Methods and results NOX2-Tg mice showed a 2- to 2.5-fold higher atrial protein content of NOX2 compared with wild-type (WT) controls, which was associated with a significant (twofold) increase in NADPH-stimulated superoxide production (2-hydroxyethidium by HPLC) in left and right atrial tissue homogenates (P = 0.004 and P = 0.019, respectively). AF susceptibility assessed in vivo by transoesophageal atrial burst stimulation was modestly increased in NOX2-Tg compared with WT (probability of AF induction: 88% vs. 69%, respectively; P = 0.037), in the absence of significant alterations in AF duration, surface ECG parameters, and LV mass or function. Mechanistic studies did not support a role for NOX2 in promoting electrical or structural remodelling, as high-resolution optical mapping of atrial tissues showed no differences in action potential duration and conduction velocity between genotypes. In addition, we did not observe any genotype difference in markers of fibrosis and inflammation, including atrial collagen content and Col1a1, Il-1β, Il-6, and Mcp-1 mRNA. Similarly, NOX2 overexpression did not have consistent effects on RyR2 Ca2+ leak nor did it affect PKA or CaMKII-mediated RyR2 phosphorylation. Finally, treatment with atorvastatin significantly inhibited atrial superoxide production in NOX2-Tg but had no effect on AF induction in either genotype. Conclusion Together, these data indicate that while atrial NOX2 overexpression may contribute to atrial arrhythmogenesis, NOX2-derived superoxide production does not affect the electrical and structural properties of the atrial myocardium.

scholarly journals Supervised Domain Adaptation for Automated Semantic Segmentation of the Atrial Cavity

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 898
Author(s):  
Marta Saiz-Vivó ◽  
Adrián Colomer ◽  
Carles Fonfría ◽  
Luis Martí-Bonmatí ◽  
Valery Naranjo
Keyword(s):  
High Performance ◽  
Computational Models ◽  
Domain Adaptation ◽  
Semantic Segmentation ◽  
Patient Specific ◽  
Mr Images ◽  
Training Samples ◽  
Volumetric Images ◽  
Acquisition Costs ◽  
Left And Right

Atrial fibrillation (AF) is the most common cardiac arrhythmia. At present, cardiac ablation is the main treatment procedure for AF. To guide and plan this procedure, it is essential for clinicians to obtain patient-specific 3D geometrical models of the atria. For this, there is an interest in automatic image segmentation algorithms, such as deep learning (DL) methods, as opposed to manual segmentation, an error-prone and time-consuming method. However, to optimize DL algorithms, many annotated examples are required, increasing acquisition costs. The aim of this work is to develop automatic and high-performance computational models for left and right atrium (LA and RA) segmentation from a few labelled MRI volumetric images with a 3D Dual U-Net algorithm. For this, a supervised domain adaptation (SDA) method is introduced to infer knowledge from late gadolinium enhanced (LGE) MRI volumetric training samples (80 LA annotated samples) to a network trained with balanced steady-state free precession (bSSFP) MR images of limited number of annotations (19 RA and LA annotated samples). The resulting knowledge-transferred model SDA outperformed the same network trained from scratch in both RA (Dice equals 0.9160) and LA (Dice equals 0.8813) segmentation tasks.

Simple single-section method for measurement of left and right atrial volumes with electron-beam CT

1999 ◽  
Vol 6 (8) ◽  
pp. 481-486 ◽  
Author(s):  
Matthew J. Budoff ◽  
Songshou Mao ◽  
ShaoJung Wang ◽  
Hamid Bakhsheshi ◽  
Bruce H. Brundage
Keyword(s):  
Electron Beam ◽  
Right Atrial ◽  
Section Method ◽  
Single Section ◽  
Electron Beam Ct ◽  
Left And Right

Abstract P603: Atrial Cardiopathy and Brain Infarction in Multiple Vascular Territories in the ARCADIA Trial

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Hooman Kamel ◽  
Keyword(s):  
Primary Outcome ◽  
Brain Infarction ◽  
Prevalence Ratio ◽  
Posterior Circulation ◽  
P Wave ◽  
Secondary Outcome ◽  
Vascular Territory ◽  
Brain Infarcts ◽  
Left And Right ◽  
Larger Sample

Introduction: Some embolic strokes of undetermined source (ESUS) are likely caused by occult cardiac embolism. One potential cardioembolic source is atrial cardiopathy without atrial fibrillation (AF). Patients with cardiac embolism more often have brain infarcts in multiple vascular territories than those with stroke mechanisms not involving a central embolic source. Hypothesis: In patients with ESUS, atrial cardiopathy is associated with brain infarction in multiple vascular territories. Methods: The ARCADIA trial is enrolling ESUS patients, screening them for atrial cardiopathy, and randomly assigning those with atrial cardiopathy to aspirin or apixaban. In the trial, atrial cardiopathy is defined as ≥1 of the following: P-wave terminal force >5,000 μV*ms in ECG lead V 1 , serum NT-proBNP >250 pg/mL, and left atrial diameter index ≥3 cm/m 2 on echocardiogram. Site investigators report whether the index CT or MRI showed brain infarction in the left carotid, right carotid, or posterior circulation, or some combination. In this analysis, our primary outcome was brain infarction in more than one of these three vascular territories. Our secondary outcome was infarction in both the left and right carotid territories. Results: Among 1,707 ESUS patients enrolled in ARCADIA, 679 (39.8%) met the trial’s randomization criteria for atrial cardiopathy and 213 (12.5%) had multi-territorial brain infarcts. The prevalence of brain infarction in more than one vascular territory was 14.0% in those with atrial cardiopathy versus 11.5% in those without (prevalence ratio, 1.22; 95% CI, 0.95-1.57). The prevalence of brain infarction in both the left and right carotid territories was 9.1% in those with atrial cardiopathy versus 7.4% in those without (prevalence ratio, 1.24; 95% CI, 0.90-1.70). Conclusions: These preliminary analyses from ARCADIA suggest a possible association between atrial cardiopathy and brain infarction in multiple vascular territories, but further analysis of a larger sample is needed to conclusively test whether our atrial cardiopathy definition is associated with the classic neuroimaging profile of cardiac embolism.

Abstract 14798: Right Atrial Function as Prognostic factor in Patients with Pulmonary Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yuko Fukuda ◽  
Hidekazu Tanaka ◽  
Yoshiki Motoji ◽  
Keiko Ryo ◽  
Hiroki Matsuzoe ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Heart Catheterization ◽  
Adverse Outcomes ◽  
P Wave ◽  
Right Atrial ◽  
Heart Catheterization ◽  
Non Invasive ◽  
Chamber View ◽  
Point Set ◽  
Right Atrial Function

Background: The development of right ventricular (RV) dysfunction in patients with pulmonary hypertension (PH) has been associated with adverse outcomes. Right atrial (RA) function could be a prognostic factors as well as RV function, but non-invasive evaluation of RA function is limited. Our objective was thus to test the hypothesis that RA function was associated with hemodynamic parameters of RV performance in PH patients. Methods: Eighty PH patients with mean pulmonary artery pressure (PAP) of 40±11mmHg (all≥25mmHg) were recruited in this study. RA function was assessed by using two-dimensional speckle-tracking strain from RV-focused apical 4-chamber view. RA strain was calculated with the reference point set at the P wave, which enabled the recognition of peak negative (RAneg), positive strain (RAposi), and the sum of those values (RAtotal), corresponding to RA contractile, conduit, and reservoir function, respectively. All patients underwent right-heart catheterization for measurement of mean PAP and pulmonary vascular resistance (PVR). Results: RAneg (r=0.24 and p=0.03), RAposi (r=0.31 and p=0.01) and RAtotal (r=0.35 and p=0.001) were significantly correlated with mean PAP. In addition, RAposi (r=0.41 and p<0.001) and RAtotal (r=0.44 and p<0.001) were also correlated with PVR. Conclusions: Non-invasively assessed RA strains were associated with mean PAP and PVR. RA strain may be of a valuable additive factor for the management of PH patients, and thus have potential clinical applications.

Widespread distribution and rate differentiation of the atrial pacemaker complex

1980 ◽  
Vol 239 (3) ◽  
pp. H406-H415 ◽  
Author(s):  
J. P. Boineau ◽  
R. B. Schuessler ◽  
D. B. Hackel ◽  
C. B. Miller ◽  
C. W. Brockus ◽  
...  
Keyword(s):  
Superior Vena ◽  
Sinus Node ◽  
P Wave ◽  
Right Atrial ◽  
Superior Vena Caval ◽  
Heart Rates ◽  
Widespread Distribution ◽  
Depolarization Wave ◽  
Lower Limits ◽  
Origin Point

In a study to examine the basis of rate-related changes in the electrocardiographic P wave we found a multicentric rather than unifocal origin of the atrial depolarization wave in dogs. Three to five pacemakers, or origin points, were distributed over a 30- to 40-mm area compared to the 11-mm size of the sinus node. Two or three of the sites could excite simultaneously, or one specific site would dominate excitation. Each separate origin point dominated excitation within a specific range of heart rates, and on reaching either the upper or lower limits of this range, a new focus abruptly dominated and initiated the atrial wave front. We have obtained evidence to suggest that these findings may be explained by a widely distributed atrial pacemaker complex. The spatial distribution of this system exceeded the dimensions of the canine sinus node by a factor of three to four times. The pacemaker centers, although distributed, were consistently located at specific positions along the superior vena caval-right atrial junction. Also, each separate pacemaker site appeared functionally differentiated to generate a specific range of heart rates. We propose that in addition to the sinus node there are other specialized atrial pacemaker centers, and that this specialization, including the differentiated response and coordination, is conferred by focal receptor characteristics and their inputs.

scholarly journals Heterotaxy syndrome: This is the left, right?

2015 ◽  
Vol 19 (2) ◽  
Author(s):  
Lili Huang ◽  
Belinda J. Mitchell ◽  
Savvas Andronikou ◽  
Zarina I. Lockhat ◽  
Farhana Suleman
Keyword(s):  
Morphological Characteristics ◽  
Imaging Modalities ◽  
Right Atrial ◽  
Abdominal Organ ◽  
Heterotaxy Syndrome ◽  
Diagnostic Challenge ◽  
Complex Disorder ◽  
Left And Right ◽  
Atrial Isomerism ◽  
Heterotaxy Syndromes

Heterotaxy syndrome is a rare and complex disorder of the chest and abdominal organ arrangements, and presents a diagnostic challenge to the radiologist. This article describes the morphological characteristics of heterotaxy and situs abnormalities, in particular left and right atrial isomerism, and suggests an approach in evaluating the spectrum of abnormalities associated with heterotaxy syndromes, using appropriate imaging modalities.

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