Catecholaminergic automatic activity in the rat pulmonary vein: electrophysiological differences between cardiac muscle in the left atrium and pulmonary vein

2009 ◽  
Vol 297 (1) ◽  
pp. H102-H108 ◽  
Author(s):  
Nicolas Doisne ◽  
Véronique Maupoil ◽  
Pierre Cosnay ◽  
Ian Findlay
Keyword(s):  
Membrane Potential ◽  
Electrical Activity ◽  
Cardiac Muscle ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
Muscle Membrane ◽  
Resting Membrane Potential ◽  
Ectopic Activity ◽  
Automatic Activity

Ectopic activity in cardiac muscle within pulmonary veins (PVs) is associated with the onset and the maintenance of atrial fibrillation in humans. The mechanism underlying this ectopic activity is unknown. Here we investigate automatic activity generated by catecholaminergic stimulation in the rat PV. Intracellular microelectrodes were used to record electrical activity in isolated strips of rat PV and left atrium (LA). The resting cardiac muscle membrane potential was lower in PV [−70 ± 1 (SE) mV, n = 8] than in LA (−85 ± 1 mV, n = 8). No spontaneous activity was recorded in PV or LA under basal conditions. Norepinephrine (10−5 M) induced first a hyperpolarization (−8 ± 1 mV in PV, −3 ± 1 mV in LA, n = 8 for both) then a slowly developing depolarization (+21 ± 2 mV after 15 min in PV, +1 ± 2 mV in LA) of the resting membrane potential. Automatic activity occurred only in PV; it was triggered at approximately −50 mV, and it occurred as repetitive bursts of slow action potentials. The diastolic membrane potential increased during a burst and slowly depolarized between bursts. Automatic activity in the PV was blocked by either atenolol or prazosine, and it could be generated with a mixture of cirazoline and isoprenaline. In both tissues, cirazoline (10−6 M) induced a depolarization (+37 ± 2 mV in PV, n = 5; +5 ± 1 mV in LA, n = 5), and isoprenaline (10−7 M) evoked a hyperpolarization (−11 ± 3 mV in PV, n = 7; −3 ± 1 mV in LA, n = 6). The differences in membrane potential and reaction to adrenergic stimulation lead to automatic electrical activity occurring specifically in cardiac muscle in the PV.

scholarly journals Automatic Activity Arising in Cardiac Muscle Sleeves of the Pulmonary Vein

Biomolecules ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Pierre Bredeloux ◽  
Come Pasqualin ◽  
Romain Bordy ◽  
Veronique Maupoil ◽  
Ian Findlay
Keyword(s):  
Cardiac Muscle ◽  
Pulmonary Vein ◽  
Left Atrial ◽  
Large Scale ◽  
Pulmonary Veins ◽  
Cellular Heterogeneity ◽  
Ectopic Activity ◽  
Automatic Activity ◽  
Multiple Signaling ◽  
Human Atrial Fibrillation

Ectopic activity in the pulmonary vein cardiac muscle sleeves can both induce and maintain human atrial fibrillation. A central issue in any study of the pulmonary veins is their difference from the left atrial cardiac muscle. Here, we attempt to summarize the physiological phenomena underlying the occurrence of ectopic electrical activity in animal pulmonary veins. We emphasize that the activation of multiple signaling pathways influencing not only myocyte electrophysiology but also the means of excitation–contraction coupling may be required for the initiation of triggered or automatic activity. We also gather information regarding not only the large-scale structure of cardiac muscle sleeves but also recent studies suggesting that cellular heterogeneity may contribute to the generation of arrythmogenic phenomena and to the distinction between pulmonary vein and left atrial heart muscle.

scholarly journals Metastatic renal cell carcinoma extending to the left atrium through the inferior pulmonary vein

2021 ◽  
Author(s):  
Alan G Dawson ◽  
Cathy J Richards ◽  
Leonidas Hadjinikolaou ◽  
Apostolos Nakas
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Metastatic Renal Cell Carcinoma ◽  
Renal Cell ◽  
Pulmonary Veins ◽  
Lower Lobe ◽  
Inferior Pulmonary Vein ◽  
The Right

Abstract Metastatic renal cell carcinoma with involvement through the pulmonary veins to the left atrium is very rare. We report the case of a 70-year-old male with metastatic renal cell carcinoma to the right lower lobe of the lung abutting the inferior pulmonary vein with extension to the left atrium without pre-operative evidence. Surgical resection was achieved through a posterolateral thoracotomy. Lung masses that abut the pulmonary veins should prompt further investigation with a pre-operative transoesophageal echocardiogram to minimize unexpected intraoperative findings.

The resting membrane potential of white muscle from brown trout (Salmo trutta) exposed to copper in soft, acidic water

2000 ◽  
Vol 203 (14) ◽  
pp. 2229-2236 ◽  
Author(s):  
M.W. Beaumont ◽  
E.W. Taylor ◽  
P.J. Butler
Keyword(s):  
Membrane Potential ◽  
Brown Trout ◽  
Salmo Trutta ◽  
White Muscle ◽  
Low Ph ◽  
Ammonium Ion ◽  
Muscle Membrane ◽  
Resting Membrane Potential ◽  
Muscle Fibres ◽  
Brown Trout Salmo Trutta

Previously, the distribution of ammonia between the intracellular and extracellular compartments has been used to predict a significant depolarisation of the resting membrane potential (E(M)) of white muscle from brown trout (Salmo trutta) exposed to a sub-lethal combination of copper and low pH. However, this prediction is based upon two assumptions (i) a relatively high membrane permeability for the ammonium ion with respect to that for ammonia gas and (ii) that this is unaltered by exposure to copper and low pH. Since there is conflicting evidence in the literature of the validity of these assumptions, in the present study E(M) was directly measured in white muscle fibres of trout exposed to copper and low pH (E(M)=−52.2+/−4.9 mV) and compared with that of unexposed, control animals (E(M)=−86.5+/−2.9 mV) (means +/− s.e.m., N=6). In confirming the predicted depolarisation, these data support the hypothesis of electrophysiological impairment as a factor in the reduction in the swimming performance of trout exposed to these pollutants. In addition, the results of this study support the role of a significant permeability of the muscle membrane to NH(4)(+) in determining the distribution of ammonia in fish.

Clarifying the anatomy of the superior sinus venosus defect

Heart ◽  
2021 ◽  
pp. heartjnl-2021-319334
Author(s):  
Jay Relan ◽  
Saurabh Kumar Gupta ◽  
Rengarajan Rajagopal ◽  
Sivasubramanian Ramakrishnan ◽  
Gurpreet Singh Gulati ◽  
...  
Keyword(s):  
Left Atrium ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
Interatrial Septum ◽  
Sinus Venosus ◽  
Caval Vein ◽  
Therapeutic Implications ◽  
Superior Caval Vein ◽  
Inferior Pulmonary Vein ◽  
The Right

ObjectivesWe sought to clarify the variations in the anatomy of the superior cavoatrial junction and anomalously connected pulmonary veins in patients with superior sinus venosus defects using computed tomographic (CT) angiography.MethodsCT angiograms of 96 consecutive patients known to have superior sinus venosus defects were analysed.ResultsThe median age of the patients was 34.5 years. In seven (7%) patients, the defect showed significant caudal extension, having a supero-inferior dimension greater than 25 mm. All patients had anomalous connection of the right superior pulmonary vein. The right middle and right inferior pulmonary vein were also connected anomalously in 88 (92%) and 17 (18%) patients, respectively. Anomalous connection of the right inferior pulmonary vein was more common in those with significant caudal extension of the defect (57% vs 15%, p=0.005). Among anomalously connected pulmonary veins, the right superior, middle, and inferior pulmonary veins were committed to the left atrium in 6, 17, and 11 patients, respectively. The superior caval vein over-rode the interatrial septum in 67 (70%) patients, with greater than 50% over-ride in 3 patients.ConclusionAnomalous connection of the right-sided pulmonary veins is universal, but is not limited to the right upper lobe. Not all individuals have over-riding of superior caval vein. In a minority of patients, the defect has significant caudal extension, and anomalously connected pulmonary veins are committed to the left atrium. These findings have significant clinical and therapeutic implications.

Effect of nicotine and acetylcholine on crustacean muscle membrane potential

1986 ◽  
Vol 61 (2) ◽  
pp. 807-809
Author(s):  
R. F. Taylor ◽  
D. T. Frazier
Keyword(s):  
Membrane Potential ◽  
Muscle Tension ◽  
Muscle Cells ◽  
Abdominal Muscle ◽  
Muscle Membrane ◽  
Resting Membrane Potential ◽  
Crustacean Muscle ◽  
Standard Glass ◽  
Before And After ◽  
Receptor Organ

We have investigated the effect of nicotine and acetylcholine on the resting membrane potential of the crayfish extensor muscle in order to determine whether crustacean muscle can be activated by cholinergic compounds. Intracellular recordings from individual deep extensor abdominal muscle cells were made using standard glass microelectrode techniques. The resting membrane potential was measured before and after treatment with glutamate, nicotine, and acetylcholine. Glutamate, which is a known activator of crayfish muscle, was used to determine whether the muscle cell preparation was viable and capable of responding to any of the test substances. Our results confirm that application of glutamate is associated with a depolarization of the muscle membrane. However, muscle cells showed no depolarization after treatment with nicotine (50 microM) or acetylcholine (66 microM). These results argue against the notion that increases in muscle tension may be responsible for the increased receptor organ discharge observed in the presence of nicotine. Rather, it supports the hypothesis that nicotine is acting directly on the mechanoreceptor membrane to change its sensitivity.

P1415Wide antral circumferential pulmonary vein isolation ablation using a novel balloon cryoablation catheter

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
A P Martin ◽  
M Fowler ◽  
N Lever
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Paroxysmal Atrial Fibrillation ◽  
Left Atrial ◽  
Pulmonary Veins ◽  
Posterior Wall ◽  
The Novel ◽  
Median Treatment

Abstract Background Pulmonary vein isolation using cryotherapy is an established treatment for the management of patients with paroxysmal atrial fibrillation. Ablation using the commercially available balloon cryocatheter has been shown to create wide antral pulmonary vein isolation. A novel balloon cryocatheter (BCC) has been designed to maintain uniform pressure and size during ablation, potentially improving contact with the antral anatomy. The extent of ablation created using the novel BCC has not previously been established. Purpose To determine the anatomical extent of pulmonary vein isolation using electroanatomical mapping when performing catheter ablation for paroxysmal atrial fibrillation using the novel BCC. Methods Nine consecutive patients underwent pre-procedure computed tomography angiography of the left atrium to quantify the chamber dimensions. An electroanatomical map was created using the cryoablation system mapping catheter and a high definition mapping system. A bipolar voltage map was obtained following ablation to determine the extent of pulmonary vein isolation ablation. A volumetric technique was used to quantify the extent of vein and posterior wall electrical isolation in addition to traditional techniques for proving entrance and exit block. Results All patients had paroxysmal atrial fibrillation, mean age 56 years, 7 (78%) male. Electrical isolation was achieved for 100% of the pulmonary veins; mean total procedure time was 109 min (+/- 26 SD), and fluoroscopy time 14.9 min (+/- 2.4 SD). The median treatment applications per vein was one (range one - four), and median treatment duration 180 sec (range 180 -240). Left atrial volume 32 mL/m2 (+/- 7 SD), and mean left atrial posterior wall area 22 cm2 (+/- 4 SD). Data was available for quantitative assessment of the extent of ablation for eight patients. No lesions (0 of 32) were ostial in nature. The antral surface area of ablation was not statistically different between the left and right sided pulmonary veins (p 0.63), which were 5.9 (1.6 SD) and 5.4 (2.1 SD) cm2 respectively. In total 50% of the posterior left atrial wall was ablated.  Conclusion Pulmonary vein isolation using a novel BCC provides a wide and antral lesion set. There is significant debulking of the posterior wall of the left atrium. Abstract Figure.

Development of the human pulmonary vein and its incorporation in the morphologically left atrium

2001 ◽  
Vol 11 (6) ◽  
pp. 632-642 ◽  
Author(s):  
Sandra Webb ◽  
Mazyar Kanani ◽  
Robert H. Anderson ◽  
Michael K. Richardson ◽  
Nigel A. Brown
Keyword(s):  
Left Atrium ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
Venous Sinus ◽  
Human Embryos ◽  
Crown Rump Length ◽  
Prepared Material ◽  
Marked Disparity ◽  
Dorsal Mesocardium ◽  
The Right

Objective: Using a newly acquired archive of previously prepared material, we sought to re-examine the origin of the pulmonary vein in the human heart, aiming to determine whether it originates from the systemic venous sinus (“sinus venosus”), or appears as a new structure draining to the left atrium. In addition, we examined the temporal sequence of incorporation of the initially solitary pulmonary vein to the stage at which four venous orifices opened to the left atrium. Methods: We studied 26 normal human embryos, ranging from 3.8 mm to 112 mm crown-rump length, and representing the period from the 12th Carnegie stage to 15 weeks of gestation. Results: The pulmonary vein canalised as a solitary vessel within the mediastinal tissues so as to connect the intraparenchymal pulmonary venous networks to the heart, using the regressing dorsal mesocardium as its portal of cardiac entry. The vein was always distinct from the tributaries of the embryonic systemic venous sinus. The orifice of the solitary vein became committed to the left atrium by growth of the vestibular spine. During development, a marked disparity was seen between the temporal and morphological patterns of incorporation of the left-sided and right-sided veins into the left atrium. The pattern of the primary bifurcation was asymmetrical, a much longer tributary being formed on the left than on the right. Contact between the atrial wall and the venous tributary on the left initially produced a shelf, which became effaced with incorporation of the two left-sided veins into the atrium. Conclusions: The initial process of formation of the human pulmonary vein is very similar to that seen in animal models. The walls of the initially solitary vein in humans become incorporated by a morphologically asymmetric process so that four pulmonary veins eventually drain independently into the left atrium. Failure of incorporation on the left side may provide the substrate for congenital division of the left atrium.

Electrophysiological observations on diaphragm muscle from normal and dystrophic hamsters

1985 ◽  
Vol 63 (11) ◽  
pp. 1474-1476 ◽  
Author(s):  
E. G. Hunter ◽  
J. Elbrink
Keyword(s):  
Membrane Potential ◽  
Electrical Activity ◽  
Action Potentials ◽  
Membrane Potentials ◽  
Diaphragm Muscle ◽  
Resting Membrane Potential ◽  
Rapid Decline ◽  
Action Potential Amplitude ◽  
Dystrophic Muscle ◽  
Adenosine Triphosphate Production

The cellular electrical activity of diaphragm from F1B normal and BIO 14.6 dystrophic hamsters has been investigated using microelectrodes. Resting membrane potentials and action potentials were recorded from control muscles and from muscles exposed to 2,4-dinitrophenol. The action potentials of normal and dystrophic diaphragms were similar in amplitude and configuration. Treatment with 2,4-dinitrophenol caused the action potential amplitude of both diaphragms to decline by similar amounts. The control resting membrane potential of diaphragm from dystrophic hamsters is not significantly different from that of normal hamsters. Treatment with 2,4-dinitrophenol caused a linear decrease in the resting membrane potentials of both groups of muscles. Dystrophic muscle, however, showed a more rapid decline in excitability when exposed to 2,4-dinitrophenol. This suggests that adenosine triphosphate production in dystrophic muscle is partially inhibited as has been suggested by other workers.

scholarly journals Variations in Draining Patterns of Right Pulmonary Veins at the Hilum and an Anatomical Classification

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
M. S. Rajeshwari ◽  
Priya Ranganath
Keyword(s):  
Atrial Fibrillation ◽  
Mr Imaging ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Ct Angiography ◽  
Pulmonary Veins ◽  
Inferior Pulmonary Vein ◽  
Superior Pulmonary Vein ◽  
Anatomical Classification ◽  
The Right

Pulmonary veins carry oxygenated blood from the lungs to the left atrium. Variations are quite common in the pattern of drainage. The present study was undertaken to evaluate the incidence of different draining patterns of the right pulmonary veins at the hilum by dissecting the human fixed cadaveric lungs. Clinically, pulmonary veins have been demonstrated to often play an important role in generating atrial fibrillation. Hence, it is important to look into the anatomy of the veins during MR imaging and CT angiography. In 53.8% of cases, the right superior lobar vein and right middle lobar vein were found to be united together to form the right superior pulmonary vein. In contrast to this, in 11.53% of cases, right middle lobar vein united with the right inferior lobar vein to form the right inferior pulmonary vein, while in 26.9% of cases, the right superior lobar vein, right middle lobar vein, and right inferior lobar vein drained separately.

Beating Heart Direct Left Atrial Access Balloon Cryoablation: Safety and Efficacy of Pulmonary Vein Isolation in an Ovine Model

2007 ◽  
Vol 2 (4) ◽  
pp. 188-191
Author(s):  
James S. Gammie ◽  
G Kwame Yankey ◽  
Timothy Nolan ◽  
Z. Jon Wu ◽  
Timm Dickfeld ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Left Atrial ◽  
Pulmonary Veins ◽  
Beating Heart ◽  
Direct Access ◽  
Large Animal ◽  
Cryoballoon Ablation ◽  
Safety And Efficacy

Objective Clinical experience with endocardial cryoablation for the surgical treatment of atrial fibrillation has demonstrated safety and efficacy. Direct access to the left atrium via a thoracoscopic or pericardial approach with a balloon-tipped cryoablation catheter might facilitate endocardial cryoablation on the beating heart. We investigated the ability of a novel cryoballoon to produce endocardial pulmonary vein ostial cryolesions on the beating heart in a large-animal model. Methods Six sheep underwent small left thoracotomy. A 10.5F catheter with a 23-mm cryoballoon was inserted directly into the left atrium under fluoroscopic and intracardiac echo (ICE) guidance. Cryoablation of the pulmonary vein ostia was performed. Animals were killed at 14 days. Pulmonary venous electrical isolation was assessed immediately before the animals were killed. Results All animals survived balloon cryoablation with no periprocedural complications. Balloon occlusion was well tolerated hemodynamically, with minimal change in blood pressure (–4 ± 6 mm Hg systolic BP) and no change in heart rate. ICE demonstrated an absence of intracardiac air or ice embolization during ablation. Mean balloon temperature was −67 ± 8°C. All animals were neurologically intact after the procedure. Five of 6 (83%) veins exhibited circumferential exit block. Phrenic nerve function was intact in all animals. On gross inspection, all lesions were circumferential and continuous without evidence of endocardial thrombus. Pathology confirmed circumferential transmurality in all treated veins. Conclusions Direct left atrial access cryoballoon ablation was effective for isolating pulmonary veins. This technology may be an important component of a minimally invasive beating heart CryoMaze procedure for the treatment of atrial fibrillation.

Sign in / Sign up

Export Citation Format

Share Document