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https://www.readbyqxmd.com/read/28627028/common-findings-in-late-gestation-fetal-echocardiography
#1
Lauren Tague, Mary T Donofrio, Amanda Fulgium, Robert McCarter, Catherine Limperopoulos, David N Schidlow
OBJECTIVES: Fetal echocardiography provides detailed information about cardiac structure and function in utero. Limited information is available regarding normal findings late in pregnancy. We therefore sought to identify and describe common cardiac findings in late gestation. METHODS: Fetuses with structurally normal hearts were identified in mid gestation within a subset of pregnant women in a prospective study. The atrioventricular valves, right and left atria, aortic isthmus and ductus arteriosus dimensions and flow abnormalities, aneurysm of the septum primum, and presence and grade of tricuspid regurgitation were assessed throughout pregnancy...
June 19, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28596994/recurrent-post-ablation-paroxysmal-atrial-fibrillation-shares-substrates-with-persistent-atrial-fibrillation-an-11-center-study
#2
Junaid A B Zaman, Tina Baykaner, Paul Clopton, Vijay Swarup, Robert C Kowal, James P Daubert, John D Day, John Hummel, Amir A Schricker, David E Krummen, Moussa Mansour, Gery F Tomassoni, Kevin R Wheelan, Mohan Vishwanathan, Shirley Park, Paul J Wang, Sanjiv M Narayan, John M Miller
INTRODUCTION: The role of atrial fibrillation (AF) substrates is unclear in patients with paroxysmal AF (PAF) that recurs after pulmonary vein isolation (PVI). We hypothesized that patients with recurrent post-ablation (redo) PAF despite PVI have electrical substrates marked by rotors and focal sources, and structural substrates that resemble persistent AF more than patients with (de novo) PAF at first ablation. METHODS: In 175 patients at 11 centers, we compared AF substrates in both atria using 64 pole-basket catheters and phase mapping, and indices of anatomical remodeling between patients with de novo or redo PAF and first ablation for persistent AF...
April 2017: JACC. Clinical Electrophysiology
https://www.readbyqxmd.com/read/28544313/neuropeptide-y-npy-inhibits-spontaneous-contraction-of-the-mouse-atrium-by-possible-activation-of-the-npy1-receptor
#3
Y Oki, H Teraoka, T Kitazawa
Neuropeptide Y (NPY) causes various central and peripheral actions through activation of G-protein-coupled NPY receptors. Although a species-dependent difference in cardiac actions of NPY has been reported, the responses to NPY have not been examined in mice, widely used experimental animals. This study aimed to clarify the responses to NPY and the receptor subtype involved in the responses in mouse atrium. Neuropeptide Y caused negative inotropic and negative chronotropic actions in spontaneous beating right atria...
March 2017: Autonomic & Autacoid Pharmacology
https://www.readbyqxmd.com/read/28529049/heterogeneity-of-transverse-axial-tubule-system-in-mouse-atria-remodeling-in-atrial-specific-na-ca-2-exchanger-knockout-mice
#4
Xin Yue, Rui Zhang, Brian Kim, Aiqun Ma, Kenneth D Philipson, Joshua I Goldhaber
Transverse-axial tubules (TATs) are commonly assumed to be sparse or absent in atrial myocytes from small animals. Atrial myocytes from rats, cats and rabbits lack TATs, which results in a characteristic "V"-shaped Ca release pattern in confocal line-scan recordings due to the delayed rise of Ca in the center of the cell. To examine TAT expression in isolated mouse atrial myocytes, we loaded them with the membrane dye Di-4-ANEPPS to label TATs. We found that >80% of atrial myocytes had identifiable TATs...
May 19, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28480585/synthesis-and-biological-evaluation-of-new-combined-%C3%AE-%C3%AE-adrenergic-blockers
#5
Andrej Némethy, Peter Vavrinec, Diana Vavrincová-Yaghi, Diana Čepcová, Svetozár Mišúth, Eva Král'ová, Ružena Čižmáriková, Eva Račanská
The synthesis, characterization, and pharmacological evaluation of new aryloxyaminopropanol compounds based on substituted (4-hydroxyphenyl)ethanone with alterations in the alkoxymethyl side chain in position 2 and with 2-methoxyphenylpiperazine in the basic part of the molecule are reported. For the in vitro pharmacological evaluation, isolated aorta and atria from normotensive Wistar rats were used. Compared to naftopidil, compounds with ethoxymethyl, propoxymethyl, butoxymethyl, and methoxyethoxymethyl substituent displayed similar α1 -adrenolytic potency...
June 2017: Archiv der Pharmazie
https://www.readbyqxmd.com/read/28461771/peroxisome-proliferator-activated-receptor-%C3%AE-is-essential-for-secretion-of-anp-induced-by-prostaglandin-d2-in-the-beating-rat-atrium
#6
Ying Zhang, Xiang Li, Li-Ping Liu, Lan Hong, Xia Liu, Bo Zhang, Cheng-Zhe Wu, Xun Cui
Prostaglandin D2 (PGD2) may act against myocardial ischemia-reperfusion (I/R) injury and play an anti-inflammatory role in the heart. Although the effect of PGD2 in regulation of ANP secretion of the atrium was reported, the mechanisms involved are not clearly identified. The aim of the present study was to investigate whether PGD2 can regulate ANP secretion in the isolated perfused beating rat atrium, and its underlying mechanisms. PGD2 (0.1 to 10 µM) significantly increased atrial ANP secretion concomitantly with positive inotropy in a dose-dependent manner...
May 2017: Korean Journal of Physiology & Pharmacology
https://www.readbyqxmd.com/read/28437860/chronic-inhibition-of-fatty-acid-amide-hydrolase-by-urb597-produces-differential-effects-on-cardiac-performance-in-normotensive-and-hypertensive-rats
#7
Anna Pędzińska-Betiuk, Jolanta Weresa, Marek Toczek, Marta Baranowska-Kuczko, Irena Kasacka, Ewa Harasim-Symbor, Barbara Malinowska
BACKGROUND AND PURPOSE: Fatty acid amide hydrolase (FAAH) inhibitors are postulated to possess anti-hypertensive potential, because their acute injection decreases BP in spontaneously hypertensive rats (SHR), partly through normalization of cardiac contractile function. Here, we examined whether the potential hypotensive effect of chronic FAAH inhibition by URB597 in hypertensive rats correlated with changes in cardiac performance. EXPERIMENTAL APPROACH: Experiments were performed using perfused hearts and left atria isolated from 8- to 10-week-old SHR, age-matched deoxycorticosterone acetate (DOCA)-salt rats and normotensive controls chronically treated with URB597 (1 mg·kg(-1) ) or vehicle...
July 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28410965/permissive-role-of-reduced-inwardly-rectifying-potassium-current-density-in-the-automaticity-of-the-guinea-pig-pulmonary-vein-myocardium
#8
Yayoi Tsuneoka, Masahiko Irie, Yusuke Tanaka, Takahiko Sugimoto, Yuka Kobayashi, Taichi Kusakabe, Keisuke Kato, Shogo Hamaguchi, Iyuki Namekata, Hikaru Tanaka
The electrophysiological properties underlying the automaticity of the guinea pig pulmonary vein myocardium were studied. About 30% of the isolated pulmonary vein tissue preparations showed spontaneous electrical activity, as shown by glass microelectrode recordings from their myocardial layer. The remaining quiescent preparations had a resting membrane potential less negative than that in the left atria. Blockade of the acetylcholine activated potassium current (IK-ACh) by tertiapin induced a depolarizing shift of the resting membrane potential and automatic electrical activity in the pulmonary vein, but not in the atria...
April 2017: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/28386845/sub-physiological-oxygen-levels-optimal-for-growth-and-survival-of-human-atrial-cardiac-stem-cells
#9
Deepthi Sreerengam RajendranNair, Jayakumar Karunakaran, Renuka R Nair
Cardiac stem cells reside in niches where the oxygen levels are close to 3%. For cytotherapy, cells are conventionally expanded in ambient oxygen (21% O2) which represents hyperoxia compared to the oxygen tension of niches. Cardiosphere-derived cells (CDCs) are then transplanted to host tissue with lower-O2 levels. The high-O2 gradient can reduce the efficacy of cultured cells. Based on the assumption that minimizing injury due to O2 gradients will enhance the yield of functionally efficient cells, CDCs were cultured in 3% O2 and compared with cells maintained in ambient O2...
April 6, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28382232/resveratrol-enhances-the-inotropic-effect-but-inhibits-the-proarrhythmic-effect-of-sympathomimetic-agents-in-rat-myocardium
#10
Jesús Hernandez-Cascales
BACKGROUND: Resveratrol is a cardioprotective agent with known antiarrhythmic effects that has recently been shown to inhibit phosphodiesterase (PDE) enzyme activity. Thus, it is possible that resveratrol increases the inotropic effect of sympathomimetic agents, as PDE inhibitors do but, unlike other PDE inhibitors, its effect may not be accompanied by proarrhythmia due to its antiarrhythmic action. This work is aimed to test this hypothesis. METHODS: This is an "in vitro" concentration-response relationship study...
2017: PeerJ
https://www.readbyqxmd.com/read/28343787/relationship-between-rotors-and-complex-fractionated-electrograms-in-atrial-fibrillation-using-a-novel-computational-analysis
#11
Pedro Adragão, Pedro Carmo, Diogo Cavaco, João Carmo, António Ferreira, Francisco Moscoso Costa, Maria Salomé Carvalho, João Mesquita, Rita Quaresma, Francisco Belo Morgado, Miguel Mendes
INTRODUCTION: Rotors and complex fractionated atrial electrograms (CFAEs) have been suggested as possible therapeutic targets in ablation of atrial fibrillation (AF). The aim of this study was to assess the relationship between rotors and CFAEs in patients with AF. METHODS: We studied 18 patients with AF (mean age 69±8 years, 33% female) who underwent rotor ablation and pulmonary vein isolation. Endocardial mapping was performed with a basket catheter to identify the presence, number and location of rotors and CFAEs...
April 2017: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
https://www.readbyqxmd.com/read/28328743/acetylcholine-atropine-interactions-paradoxical-effects-on-atrial-fibrillation-inducibility
#12
Yu Liu, Benjamin J Scherlag, Youqi Fan, Wenfang Xia, He Huang, Sunny S Po
Atropine (ATr) is well known as a cholinergic antagonist, however, at low concentrations ATr could paradoxically accentuate the parasympathetic actions of acetylcholine (ACh). In 22 pentobarbital anesthetized dogs, via a left and right thoracotomy, a leak-proof barrier was attached to isolate the atrial appendages (AAs) from the rest of the atria. In group 1 (Ach+ATr+Ach), ACh, 100 mM, was placed on the AA followed by the application of ATr, 2 mg/mL. The average atrial fibrillation (AF) duration was 17 ± 7 minutes...
June 2017: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/28255079/frequency-gradient-within-coronary-sinus-predicts-the-long-term-outcome-of-persistent-atrial-fibrillation-catheter-ablation
#13
Xiaomeng Yin, Ziming Zhao, Lianjun Gao, Dong Chang, Xianjie Xiao, Rongfeng Zhang, Qi Chen, Jie Cheng, Yanzong Yang, Yutao Xi, Yunlong Xia
BACKGROUND: The coronary sinus (CS), as a junction of the atria, contributes to atrial fibrillation (AF) by developing unstable reentry, and isolating the atria by ablation at the CS could terminate AF. The present study evaluated whether AF activities at the CS in a subset of patients contributed to AF maintenance and predicted clinical outcome of ablation. METHODS AND RESULTS: We studied 122 consecutive patients who had a first-time radiofrequency ablation for persistent AF...
March 2, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28243733/biophysical-and-molecular-comparison-of-sodium-current-in-cells-isolated-from-canine-atria-and-pulmonary-vein
#14
Hector Barajas-Martinez, Robert J Goodrow, Dan Hu, Payal Patel, Mayurika Desai, Brian K Panama, Jacqueline A Treat, Gary L Aistrup, Jonathan M Cordeiro
The collar of the pulmonary vein (PV) is the focal point for the initiation of atrial arrhythmias, but the mechanisms underlying how PV cells differ from neighboring left atrial tissue are unclear. We examined the biophysical and molecular properties of INa in cells isolated from the canine pulmonary sleeve and compared the properties to left atrial tissue. PV and left atrial myocytes were isolated and patch clamp techniques were used to record INa. Action potential recordings from either tissue type were made using high-resistance electrodes...
February 27, 2017: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/28229413/cardiac-progenitor-cell-extraction-from-human-auricles
#15
Paolo Di Nardo, Francesca Pagliari
For many years, myocardial tissue has been considered terminally differentiated and, thus, incapable of regenerating. Recent studies have shown, instead, that cardiomyocytes, at least in part, are slowly substituted by new cells originating by precursor cells mostly embedded into the heart apex and in the atria. We have shown that an elective region of progenitor cell embedding is represented by the auricles, non-contractile atria appendages that can be easily sampled without harming the patient. The protocol here reported describes how from auricles a population of multipotent, cardiogenic cells can be isolated, cultured, and differentiated...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28223472/overexpression-of-sarcoendoplasmic-reticulum-calcium-atpase-2a-promotes-cardiac-sympathetic-neurotransmission-via-abnormal-endoplasmic-reticulum-and-mitochondria-ca-2-regulation
#16
Julia Shanks, Neil Herring, Errin Johnson, Kun Liu, Dan Li, David J Paterson
Reduced cardiomyocyte excitation-contraction coupling and downregulation of the SERCA2a (sarcoendoplasmic reticulum calcium ATPase 2a) is associated with heart failure. This has led to viral transgene upregulation of SERCA2a in cardiomyocytes as a treatment. We hypothesized that SERCA2a gene therapy expressed under a similar promiscuous cytomegalovirus promoter could also affect the cardiac sympathetic neural axis and promote sympathoexcitation. Stellate neurons were isolated from 90 to 120 g male, Sprague-Dawley, Wistar Kyoto, and spontaneously hypertensive rats...
April 2017: Hypertension
https://www.readbyqxmd.com/read/28219708/novel-technique-to-determine-the-pka-of-clonidine-at-prejunctional-%C3%AE-2-adrenoceptors-in-cardiac-and-vascular-sympathetic-transmission
#17
James A Angus, Pravin Rajasekaran, Christine E Wright
Analytical pharmacology draws heavily on the concept of equilibrium of agonist and silent antagonist concentrations competing at a specific receptor site. This condition breaks down in nerve transmission when transmitter release is inhibited by prejunctional α2-adrenoceptors activated by an agonist such as clonidine. We have developed a method that allows the agonist dissociation constant KA of clonidine to be determined in a robust isolated right atrial assay of mouse, rat and guinea pig. By applying low numbers of field pulses 1-4 to prevent autoinhibitory feedback, clonidine shifted the nerve pulse stimulation-tachycardia curves to the right...
April 5, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28217229/evaluation-of-the-characteristics-of-rotational-activation-at-high-dominant-frequency-and-complex-fractionated-atrial-electrogram-sites-during-atrial-fibrillation
#18
Koji Kumagai, Kentaro Minami, Daisuke Kutsuzawa, Shigeru Oshima
BACKGROUND: High-dominant frequency (DF) and continuous complex fractionated atrial electrogram (CFAE) sites as surrogates for localized sources maintaining atrial fibrillation (AF) are potential AF ablation targets. This study aimed to evaluate the characteristics of a rotational activation at high-DF and continuous CFAE sites in AF patients. METHODS: Thirty-two consecutive AF patients (5 paroxysmal and 27 non-paroxysmal) underwent ablation using the NavX system...
February 2017: Journal of Arrhythmia
https://www.readbyqxmd.com/read/28155995/sinus-node-dysfunction-and-atrial-fibrillation-a-reversible-phenomenon
#19
REVIEW
Larry R Jackson, Bharath Rathakrishnan, Kristen Campbell, Kevin L Thomas, Jonathan P Piccini, Tristram Bahnson, Jonathan A Stiber, James P Daubert
BACKGROUND: Symptomatic sinus node dysfunction (SND) consists of a variety of manifestations, including tachycardia-bradycardia syndrome. Atrial fibrillation (AF) is commonly associated with SND, which complicates the management of both conditions. This paper reviews the epidemiology, pathophysiology, and clinical trial data investigating therapeutic approaches for treatment of patients with both SND and AF. METHODS: The authors reviewed articles published in English describing the epidemiology, pathophysiology, and therapeutic approaches for patients with SND and AF...
February 3, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28133984/new-arylsparteine-derivatives-as-positive-inotropic-drugs
#20
Vito Boido, Marcella Ercoli, Michele Tonelli, Federica Novelli, Bruno Tasso, Fabio Sparatore, Elena Cichero, Paola Fossa, Paola Dorigo, Guglielmina Froldi
Positive inotropic agents are fundamental in the treatment of heart failure; however, their arrhythmogenic liability and the increased myocardial oxygen demand strongly limit their therapeutic utility. Pursuing our study on cardiovascular activities of lupin alkaloid derivatives, several 2-(4-substituted-phenyl)-2-dehydrosparteines and 2-(4-substituted-phenyl)sparteines were prepared and tested for inotropic and chronotropic activities on isolated guinea pig atria. Four compounds (6b, 6e, 7b, and 7f) exhibited significant inotropism that, at the higher concentrations, was followed by negative inotropism or toxicity...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
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