New insights into the atrial electrophysiology of rodents using a novel modality: the miniature-bipolar hook electrode

2008 ◽  
Vol 295 (4) ◽  
pp. H1460-H1469 ◽  
Author(s):  
Yoram Etzion ◽  
Michal Mor ◽  
Aryeh Shalev ◽  
Shani Dror ◽  
Ohad Etzion ◽  
...  
Keyword(s):  
Right Atrium ◽  
Cycle Length ◽  
Rate Adaptation ◽  
Right Atrial ◽  
Reverse Remodeling ◽  
Atrial Pacing ◽  
Anesthetized Rats ◽  
Atrial Electrophysiology ◽  
The Right ◽  
First Time

Studies of atrial electrophysiology (EP) in rodents are challenging, and available data are sparse. Herein, we utilized a novel type of bipolar electrode to evaluate the atrial EP of rodents through small lateral thoracotomy. In anesthetized rats and mice, we attached two bipolar electrodes to the right atrium and a third to the right ventricle. This standard setup enabled high-resolution EP studies. Moreover, a permanent implantation procedure enabled EP studies in conscious freely moving rats. Atrial EP was evaluated in anesthetized rats, anesthetized mice (ICR and C57BL6 strains), and conscious rats. Signal resolution enabled atrial effective refractory period (AERP) measurements and first time evaluation of the failed 1:1 atrial capture, which was unexpectedly longer than the AERP recorded at near normal cycle length by 27.2 ± 2.3% in rats ( P < 0.0001; n = 35), 31.7 ± 8.3% in ICR mice ( P = 0.0001; n = 13), and 57.7 ± 13.7% in C57BL6 mice ( P = 0.015; n = 4). While AERP rate adaptation was noted when 10 S1s at near normal basic cycle lengths were followed by S2 at varying basic cycle length and S3 for AERP evaluation, such rate adaptation was absent using conventional S1S2 protocols. Atrial tachypacing in rats shortened the AERP values on a timescale of hours, but a reverse remodeling phase was noted thereafter. Comparison of left vs. right atrial pacing in rats was also feasible with the current technique, resulting in similar AERP values recorded in the low right atrium. In conclusion, our findings indicate that in vivo rate adaptation of the rodent atria is different than expected based on previous ex vivo recordings. In addition, atrial electrical remodeling of rats shows unique remodeling-reverse remodeling characteristics that are described here for the first time. Further understanding of these properties should help to determine the clinical relevance as well as limitations of atrial arrhythmia models in rodents.

Loss of atrial contractility is primary cause of atrial dilatation during first days of atrial fibrillation

2004 ◽  
Vol 287 (5) ◽  
pp. H2324-H2331 ◽  
Author(s):  
Ulrich Schotten ◽  
Sunniva de Haan ◽  
Hans-Ruprecht Neuberger ◽  
Sabine Eijsbouts ◽  
Yuri Blaauw ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Right Atrium ◽  
Contractile Function ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Rapid Pacing ◽  
The Mean ◽  
The Right

Atrial fibrillation (AF) induces a progressive dilatation of the atria which in turn might promote the arrhythmia. The mechanism of atrial dilatation during AF is not known. To test the hypothesis that loss of atrial contractile function is a primary cause of atrial dilatation during the first days of AF, eight goats were chronically instrumented with epicardial electrodes, a pressure transducer in the right atrium, and piezoelectric crystals to measure right atrial diameter. AF was induced with the use of repetitive burst pacing. Atrial contractility was assessed during sinus rhythm, atrial pacing (160-, 300-, and 400-ms cycle length), and electrically induced AF. The compliance of the fibrillating right atrium was measured during unloading the atria with diuretics and loading with 1 liter of saline. All measurements were repeated after 6, 12, and 24 h of AF and then once a day during the first 5 days of AF. Recovery of the observed changes after spontaneous cardioversion was also studied. After 5 days of AF, atrial contractility during sinus rhythm or slow atrial pacing was greatly reduced. During rapid pacing (160 ms) or AF, the amplitude of the atrial pressure waves had declined to 20% of control. The compliance of the fibrillating atria increased twofold, whereas the right atrial pressure was unchanged. As a result, the mean right atrial diameter increased by ∼12%. All changes were reversible within 3 days of sinus rhythm. We conclude that atrial dilatation during the first days of AF is due to an increase in atrial compliance caused by loss of atrial contractility during AF. Atrial compliance and size are restored when atrial contractility recovers after cardioversion of AF.

Transitions among atrial fibrillation, atrial flutter, and sinus rhythm during procainamide infusion and vagal stimulation in dogs with sterile pericarditis

1991 ◽  
Vol 69 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Pierre L. Pagé ◽  
Hamid Hassanalizadeh ◽  
René Cardinal
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Atrial Flutter ◽  
Right Atrium ◽  
Cycle Length ◽  
Vagal Stimulation ◽  
Right Atrial ◽  
Free Wall ◽  
Circus Movement ◽  
The Right

The mechanism of atrial flutter and fibrillation induced by rapid pacing in 22 dogs with 3-day-old sterile pericarditis was investigated by computerized epicardial mapping of atrial activation before and after administration of agents known to modify atrial electrophysiologic properties: procainamide, isoproterenol, and electrical stimulation of the vagosympathetic trunks. Before the administration of any of these agents, a total of 30 episodes of sustained atrial flutter (> 1 min duration, monomorphic; regular cycle length, 127 ± 12 ms, mean ± SD) was induced in 15 out of 22 dogs and 9 episodes of unstable atrial flutter (duration, <1 min; cycle length, 129 ± 34 ms; monomorphic, alternating with fibrillation) were induced in the remaining 7 preparations. In the latter, administration of procainamide transformed unstable atrial flutter and atrial fibrillation to sustained atrial flutter (cycle length, 142 ± 33 ms; n = 9 episodes). During control atrial flutter, atrial maps displayed circus movement of excitation in the right atrial free wall with faster conduction parallel to the orientation of intra-atrial myocardial bundles. Vagal stimulation changed atrial flutter to atrial fibrillation in 32 of 73 trials; this was associated with acceleration of conduction in the lower right atrium, leading to fragmentation of the major wave front. Isoproterenol produced a 6–25% increase of the atrial rate in 6 out of 14 trials of atrial flutter and induced atrial fibrillation in 4. After procainamide, the reentrant pathway was lengthened and conduction was slowed further in the right atrium. Maps obtained during unstable atrial flutter showed incomplete circuits involving the right atrium. Following procainamide infusion, the area of functional dissociation or block was enlarged and a stable circus movement pattern, which was similar to the pattern seen in control atrial flutter, was established in the right atrium. We conclude that (1) the transitions among atrial fibrillation, atrial flutter, and sinus rhythm occur between different functional states of the same circus movement substratum primarily located in the lower right atrial free wall, and (2) the anisotropic conduction properties of the right atrium may contribute to these reentrant arrhythmias and may be potentiated by acute pericarditis.Key words: atrial flutter, atrial fibrillation, atrial mapping, antiarrhythmic drugs, vagal stimulation.

Closure of Secundum Atrial Septal Defect with Autologous Right Atrial Patch: Case Report

2005 ◽  
Vol 8 (2) ◽  
pp. 96 ◽  
Author(s):  
Osman Tansel Dar�in ◽  
Alper Sami Kunt ◽  
Mehmet Halit Andac
Keyword(s):  
Atrial Septal Defect ◽  
Right Atrium ◽  
Septal Defect ◽  
Complete Recovery ◽  
Interatrial Septum ◽  
Right Atrial ◽  
Atrial Wall ◽  
Residual Shunt ◽  
Asd Closure ◽  
The Right

Background: Although various synthetic materials and pericardium have been used for atrial septal defect (ASD) closure, investigators are continuing to search for an ideal material for this procedure. We report and evaluate a case in which autologous right atrial wall tissue was used for ASD closure. Case: In this case, we closed a secundum ASD of a 22-year-old woman who also had right atrial enlargement due to the defect. After establishing standard bicaval cannulation and total cardiopulmonary bypass, we opened the right atrium with an oblique incision in a superior position to a standard incision. After examining the secundum ASD, we created a flap on the inferior rim of the atrial wall. A stay suture was stitched between the tip of the flap and the superior rim of the defect, and suturing was continued in a clockwise direction thereafter. Considering the size and shape of the defect, we incised the inferior attachment of the flap, and suturing was completed. Remnants of the flap on the inferior rim were resected, and the right atrium was closed in a similar fashion. Results: During an echocardiographic examination, neither a residual shunt nor perigraft thrombosis was seen on the interatrial septum. The patient was discharged with complete recovery. Conclusion: Autologous right atrial patch is an ideal material for ASD closure, especially in patients having a large right atrium. A complete coaptation was achieved because of the muscular nature of the right atrial tissue and its thickness, which is a closer match to the atrial septum than other materials.

scholarly journals P686 Right atrial, right ventricular and pulmonary cement embolism: a rare complication of percutaneous vertebroplasty

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
S Akhunova ◽  
R Khayrullin ◽  
N Stekolshchikova ◽  
M Samigullin ◽  
V Padiryakov
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Atrium ◽  
Percutaneous Vertebroplasty ◽  
Rare Complication ◽  
Clinical Manifestations ◽  
Stable Condition ◽  
Right Atrial ◽  
Cement Embolism ◽  
The Right

Abstract A 68-year-old man was admitted to the hospital with complaints of pain in the lumbar spine. He had L5 disc herniation, Spinal stenosis of the L5 root canal - S1 on the right in the past medical history. Percutaneous vertebroplasty at the level of L3 and Th8 vertebral bodies was performed six months ago due to painful vertebral hemangioma. The man is suffering from arterial hypertension, receives antihypertensive therapy. During routine transthoracic echocardiography, a hyperechoic structure with a size of 9.5 x 0.9 cm was found in the right atrium and right ventricle. Chest computed tomography with contrast enhancement revealed signs of bone cement in the right atrium and right ventricle, in the right upper lobe artery, in the branches of the upper lobe artery, in the paravertebral venous plexuses. Considering the duration of the disease, the stable condition, the absence of clinical manifestations and disorders of intracardiac hemodynamics, it was decided to refrain from surgical treatment. Antiplatelet therapy and dynamic observation were recommended. Conclusion Percutaneous vertebroplasty is a modern minimally invasive surgical procedure for the treatment of degenerative-dystrophic diseases of the spine. However, the cement can penetrate into the paravertebral veins and migrate to the right chambers of the heart and the pulmonary artery. This clinical case demonstrates asymptomatic cement embolism of the right chambers of the heart and pulmonary artery after percutaneous vertebroplasty, detected incidentally during routine echocardiography. Abstract P686 Figure.

scholarly journals Advanced Hepatocellular Carcinoma with Subtotal Occlusion of the Inferior Vena Cava and a Right Atrial Mass

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Christian Steinberg ◽  
Suzanne Boudreau ◽  
Felix Leveille ◽  
Marc Lamothe ◽  
Patrick Chagnon ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Inferior Vena Cava ◽  
Right Atrium ◽  
Inferior Vena ◽  
Vena Cava ◽  
Great Majority ◽  
Right Atrial ◽  
Advanced Hepatocellular Carcinoma ◽  
Regional Lymph Nodes ◽  
The Right

Hepatocellular carcinoma usually metastasizes to regional lymph nodes, lung, and bones but can rarely invade the inferior vena cava with intravascular extension to the right atrium. We present the case of a 75-year-old man who was admitted for generalized oedema and was found to have advanced HCC with invasion of the inferior vena cava and endovascular extension to the right atrium. In contrast to the great majority of hepatocellular carcinoma, which usually develops on the basis of liver cirrhosis due to identifiable risk factors, none of those factors were present in our patient.

Effect of canine cardiac nerves on heart rate, rhythm, and pacemaker location

1986 ◽  
Vol 250 (4) ◽  
pp. H630-H644 ◽  
Author(s):  
R. B. Schuessler ◽  
J. P. Boineau ◽  
A. C. Wylds ◽  
D. A. Hill ◽  
C. B. Miller ◽  
...  
Keyword(s):  
Heart Rate ◽  
Right Atrium ◽  
General Trend ◽  
Canine Model ◽  
Right Atrial ◽  
Sympathetic Stimulation ◽  
Open Chest ◽  
Left Posterior ◽  
The Right ◽  
Cardiac Nerves

In open-chest dogs, right- and left-sided cardiac nerves were stimulated to determine their effect on heart rate, rhythm, and pacemaker location. The majority of the nerves produced chronotropic changes; 72% of the induced rhythms originated from within the atrial pacemaker complex. Ten percent of the stimulations produced an atrio-ventricular (AV) nodal rhythm; most of the time this was induced by the left posterior and anterior ansae and ventrolateral nerves. The dominance of a lateral right atrial pacemaker was observed in 8% of the stimulations; the dorsal cardiac and innominate nerves induced this rhythm the majority of the time. The general trend was for a cranial shift in the location of the pacemaker within the pacemaker complex with sympathetic stimulation and a caudal shift with parasympathetic stimulation. Exceptions to the pattern may be explained by the preferential effect of the nerves on the pacemakers in the right atrium. The study demonstrates, in the canine model, that in addition to the sinus and AV nodes, there is a system of pacemakers controlled by the cardiac nerves.

Ping-Pong Ball, Tumor or Thrombus in the Right Atrium? A Case Report

2018 ◽  
Vol 9 (3) ◽  
pp. 350-351
Author(s):  
Stephanie Ghaleb ◽  
Bryant Roosevelt ◽  
James Cnota
Keyword(s):  
Clinical Judgment ◽  
Right Atrium ◽  
Frozen Section ◽  
Noninvasive Imaging ◽  
Neoadjuvant Treatment ◽  
Lower Lobe ◽  
Final Diagnosis ◽  
Right Atrial ◽  
Right Atrial Mass ◽  
The Right

Tumors and thrombi are the most common cardiac masses of the right atrium. The use of noninvasive imaging to differentiate between the two can be deceiving, and the clinical judgment of a cardiologist and the emergency of the situation should be partnered to decide on the next step of the management. We present the case of a 29-year-old lady who was receiving neoadjuvant treatment for her rhabdomyosarcoma and was incidentally found to have a very large, very mobile right atrial mass that was protruding in the right ventricle with each cardiac cycle along with findings of a small segmental right lower lobe pulmonary embolism. Along with noninvasive imaging, frozen section analysis procured the wrong diagnosis, and the mass was ultimately found to be a right atrial thrombus on definite pathology review. Exact management of right atrial masses continues to be not well delineated, and when in doubt, final diagnosis might need to be “a posteriori” and based on the treatment response.

scholarly journals P1498 Right atrial thrombus in a young septic patient with lymphoma

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
S Habjan ◽  
B Erzen ◽  
M Miklic ◽  
A Skarlovnik
Keyword(s):  
Staphylococcus Aureus ◽  
Right Atrium ◽  
Inflammatory Markers ◽  
Clinical Status ◽  
Left Knee ◽  
Blood Cultures ◽  
Right Atrial ◽  
Atrial Thrombus ◽  
The Right ◽  
And Staphylococcus Aureus

Abstract Background Catheter-related right atrial thrombosis is a rare, but potentially life threatening complication in patients with central venous catheters (CVCs). Echocardiography is an indispensable tool in the diagnosis of right atrial thrombosis. We present a case of a young man with lymphoma, Staphylococcus aureus sepsis and a peripherally inserted central catheter (PICC) who had a septic thrombus in the right atrium. Case summary A 23-year-old male patient with recently diagnosed Hodgkin’s lymphoma had an inserted PICC for the purpose of chemotherapy application. Three days after the first chemotherapy application a thrombosis of the cephalic and subclavian veins at the site of PICC was found. The PICC was removed and the patient was treated with therapeutic doses of dalteparin. A day after the discovery of thrombosis, the patient became clinically septic, with high inflammatory markers and Staphylococcus aureus was isolated from his blood cultures. He was promptly treated with flucloxacillin. Due to pain in his left knee, a knee puncture was performed, and Staphylococcus aureus was isolated also from the knee synovial fluid. A transthoracic echocardiography revealed a 2.8 x 2.8 cm sessile thrombus on the lateral wall of the right atrium. There were no vegetations on the tricuspid or other valves. Due to increasing pain in his left knee and an increase in inflammatory markers a synovectomy was performed. After the operation the clinical status improved and the inflammatory parameters decreased. A magnetic resonance imaging of the heart was performed, which confirmed the thrombus described by echocardiography and excluded the presence of abscesses. All the time the patient was treated in the intensive care unit with standard heparin, flucloxacillin, and piperacillin/tazobactam due to neutropenia. The inflammatory markers slowly decreased and all further blood cultures were negative. Follow-up echocardiography after 16 days of antibiotic and anticoagulant therapy revealed that the mass in the right atrium, attached on the lateral atrium wall, was slightly smaller than before. The mass was centrally un-echogenic with echogenic cover, appearing as a partial regression of the septic thrombus with a central colliquation. The heart valves remained free of vegetations. There was a minor pericardial effusion, with no signs of constriction. Due to improved clinical status the patient was able to start with chemotherapy again after a pause of three weeks. Conclusion The patient had three important risk factors for thrombosis: PICC, sepsis and malignancy. Echocardiography is an important tool for mass diagnosis and the exclusion of vegetations in a septic patient. Often there is a need for further specification of the mass etiology or for the exclusion of other pathology, like abscesses in our case. Magnetic resonance is an important tool that can complement the echocardiographic examination. Abstract P1498 Figure. Right atrial thrombus

scholarly journals Transthoracic Right Atrial Cannulation for Total Parenteral Nutrition — Case Report

1981 ◽  
Vol 9 (1) ◽  
pp. 53-57 ◽  
Author(s):  
L. Hayden ◽  
G. Ramsey Stewart ◽  
D. C. Johnson ◽  
M. McD. Fisher
Keyword(s):  
Parenteral Nutrition ◽  
Total Parenteral Nutrition ◽  
Right Atrium ◽  
Venous Catheter ◽  
Right Atrial ◽  
X Ray ◽  
Right Thoracotomy ◽  
Right Atrial Appendage ◽  
The Right ◽  
Nutrition Programme

A man with severe peripheral vascular disease and requiring total parenteral nutrition because of short bowel syndrome was referred because a central venous catheter could not be inserted by conventional techniques. A right thoracotomy was performed and a Hickman catheter inserted via the right atrial appendage into the right atrium. This catheter was used for a total of seven months for total parenteral nutrition. For the last two months of this time, the patient was maintained at home on a Home Parenteral Nutrition Programme. After four months of total parenteral nutrition the patient developed recurrent fevers and the catheter was found to have migrated from the right atrium into the pulmonary artery. The catheter was resited under x-ray control and used for a further three months until the recurrence of fever and dyspnoea heralded the onset of septic pulmonary emboli resulting in his death.

scholarly journals Giant right atrial myxoma: A rare cause of cardiovascular collapse

2019 ◽  
Vol 7 ◽  
pp. 2050313X1984146
Author(s):  
Andres Beiras-Fernandez ◽  
Angela Kornberger ◽  
Hazem El-Beyrouti ◽  
Christian-Friedrich Vahl
Keyword(s):  
Heart Failure ◽  
Right Ventricle ◽  
Right Atrium ◽  
Heart Valves ◽  
Surgical Intervention ◽  
Atrial Myxoma ◽  
Right Atrial ◽  
Cardiovascular Collapse ◽  
Right Atrial Myxoma ◽  
The Right

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.

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