tbuckley/cabot-search huggingface dataset:
Stimulation of serotonin2 receptors in the ventrolateral medulla of the cat results in nonuniform increases in sympathetic outflow.
Authors: A KMandal, K JKellar, W PNorman, R AGillis
Journal: Circulation Research (1990)

Topical application of the serotonin2 agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane or DOI, in a dose of 30 micrograms/side to the intermediate area of the ventrolateral surface of the medulla produced a significant increase in mean arterial pressure with no significant change in heart rate both in intact animals (n = 8) and in cervically vagotomized animals (n = 3). The pressor response of DOI was blocked by pretreatment of the intermediate area with ketanserin, a serotonin2 antagonist (n = 7). Pretreatment with intravenous phentolamine did not block the pressor response of DOI (n = 3). However, this pressor response could be counteracted by intravenous propranolol (n = 5) or by bilateral stellate ganglionectomy (n = 3). These data suggest that sympathoexcitation by centrally applied DOI selectively increased cardiac inotropy but not chronotropy. Further studies indicate that DOI increased contractile force without increasing heart rate and that the positive inotropic effect of DOI could be coun...
Calmodulin modulation of single sarcoplasmic reticulum Ca2+-release channels from cardiac and skeletal muscle.
Authors: J SSmith, ERousseau, GMeissner
Journal: Circulation Research (1989)

Sarcoplasmic reticulum (SR) contains a Ca2+-conducting channel that is believed to play a central role in excitation-contraction coupling by releasing the Ca2+ necessary for muscle contraction. The effects of calmodulin on single cardiac and skeletal muscle SR Ca2+-release channels were studied using the planar lipid bilayer-vesicle fusion technique. Calmodulin inhibited Ca2+-release channel opening by reducing the mean duration of single-channel open events without having an effect on single-channel conductance. Inhibition by calmodulin was dependent on Ca2+ concentration and occurred in the absence of ATP. The effects of calmodulin were reversed by mastoparan, a calmodulin-binding peptide. Two other calmodulin antagonists [calmidazolium and N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide] modified the gating behavior of the channel in the absence of exogenous calmodulin in a concentration- and Ca2+-dependent manner. Our results suggest that calmodulin can modulate excitation-contraction coupling by ...
Double-outlet right ventricle: wide-angle two-dimensional echocardiographic observations.
Authors: D JHagler, A JTajik, J BSeward, D DMair, D GRitter
Journal: Circulation (1981)

M-mode echocardiographic delineation of double-outlet right ventricle (DORV) has relied primarily on the demonstration of mitral-semilunar valve discontinuity--a feature that requires an interpretation of spatial anatomic relationships. Thirty-six patients with DORV were examined by wide-angle real-time two-dimensional echocardiography. Anatomic diagnosis was established by surgery in 28 patients and by angiography alone in eight. Typical two-dimensional echocardiographic features were (1) parallel orientation and origin of both great arteries from the anterior right ventricle, (2) mitral-semilunar valve discontinuity demonstrated on parasternal long-axis scans by the presence of muscular conus separation, and (3) absence of left ventricular outflow other than a ventricular septal defect. This technique also allows better recognition of spatial orientation of the great arteries and the position of the ventricular septal defect relative to the great arteries. An unexpected finding was a high incidence of a...
Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory pathways guided by accessory pathway activation potentials.
Authors: J HMcClelland, XWang, K JBeckman, H AHazlitt, M IPrior, HNakagawa, RLazzara, W MJackman
Journal: Circulation (1994)

BACKGROUNDAccessory pathways (APs) exhibiting Mahaim fiber physiology (antegrade conduction only, long conduction time, and decremental properties) often connect the lateral right atrium to the right bundle branch (right atriofascicular pathways). Potentials from these pathways have not been recorded previously. The purpose of this study was to determine whether AP activation potentials could be recorded from right atriofascicular APs and to determine whether these potentials could be used to localize a site for catheter ablation.METHODS AND RESULTSOf 26 consecutive patients referred for catheter ablation of an AP producing a preexcited (antidromic) atrioventricular (AV) reentrant tachycardia having a left bundle branch block pattern with short ventriculoatrial and long AV intervals, 23 (88.5%) were found to have a right atriofascicular AP. During antidromic AV reentrant tachycardia, (1) right atrial extrastimuli (that did not penetrant tachycardia, (1) right atrial extrastimuli (that did not penetrate ...
Concurrent diabetes and heart failure: interplay and novel therapeutic approaches
Authors: Qutuba G Karwi, Kim L Ho, Simran Pherwani, Ezra B Ketema, Qiuyu Sun, Gary D Lopaschuk
Journal: Cardiovascular Research (2021)

Abstract Diabetes mellitus increases the risk of developing heart failure, and the co-existence of both diseases worsens cardiovascular outcomes, hospitalization, and the progression of heart failure. Despite current advancements on therapeutic strategies to manage hyperglycaemia, the likelihood of developing diabetes-induced heart failure is still significant, especially with the accelerating global prevalence of diabetes and an ageing population. This raises the likelihood of other contributing mechanisms beyond hyperglycaemia in predisposing diabetic patients to cardiovascular disease risk. There has been considerable interest in understanding the alterations in cardiac structure and function in diabetic patients, collectively termed as ‘diabetic cardiomyopathy’. However, the factors that contribute to the development of diabetic cardiomyopathies are not fully understood. This review summarizes the main characteristics of diabetic cardiomyopathies, and the basic mechanisms that contribute to its occurrence. This includes perturbations in insulin resistance, fuel preference, reactive oxygen species generation, inflammation, cell death pathways, neurohormonal mechanisms, advanced glycated end-products accumulation, lipotoxicity, glucotoxicity, and post-translational modifications in the heart of the diabetic. This review also discusses the impact of antihyperglycaemic therapies on the development of heart failure, as well as how current heart failure therapies influence glycaemic control in diabetic patients. We also highlight the current knowledge gaps in understanding how diabetes induces heart failure.
Clinical and Organizational Factors Associated With Feeding Tube Use Among Nursing Home Residents With Advanced Cognitive Impairment
Authors: S. L. Mitchell
Journal: JAMA (2003)

<h3>Context</h3> Empiric data and expert opinion suggest that use of feeding tubes is not beneficial for older persons with advanced dementia. Previous research has shown a 10-fold variation in this practice across the United States. <h3>Objective</h3> To identify the facility and resident characteristics associated with feeding tube use among US nursing homes residents with severe cognitive impairment. <h3>Design, Setting, and Participants</h3> Cross-sectional study of all residents with advanced cognitive impairment who had Minimum Data Set assessments within 60 days of April 1, 1999, (N = 186 835) and who resided in Medicare- or Medicaid-certified US nursing homes. <h3>Main Outcomes Measures</h3> Facility and resident characteristics described in the 1999 On-line Survey Certification of Automated Records and the 1999 Minimum Data Set. Multivariate analysis using generalized estimating equations determined the facility and resident factors independently associated with feeding tube use. <h3>Results</h3> Thirty-four percent of residents with advanced cognitive impairment had feeding tubes (N = 63 101). Resident characteristics associated with a greater likelihood of feeding tube use included younger age, nonwhite race, male sex, divorced marital status, lack of advance directives, a recent decline in functional status, and no diagnosis of Alzheimer disease. Controlling for these patient factors, residents living in facilities that were for profit (adjusted odds ratio [OR], 1.09; 95% confidence interval [CI], 1.06-1.12); located in an urban area (OR, 1.14; 95% CI, 1.11-1.16); having more than 100 beds (OR, 1.04; 95% CI, 1.01-1.07); and lacking a special dementia care unit (OR, 1.11; 95% CI, 1.07-1.15) had a higher likelihood of having a feeding tube. Additionally, feeding tube use was more likely among residents living in facilities that had a smaller proportion of residents with do-not-resuscitate orders, had a higher prevalence of nonwhite residents, and lacked a nurse practitioner or physician assistant on staff. <h3>Conclusions</h3> More than one third of severely cognitively impaired residents in US nursing homes have feeding tubes. Feeding tube use is independently associated with both the residents' clinical characteristics and the nursing homes' fiscal, organizational, and demographic features.
Cervical Aortic Arch
Authors: Tarun W Dasari, Marco Paliotta
Journal: New England Journal of Medicine (2014)

A healthy 23-year-old woman was referred for evaluation of a murmur and an increasingly pulsatile neck mass, first noted 2 years before presentation. Physical examination revealed a prominent pulsation in the right side of the neck, shown in a video, and an early diastolic murmur.
Improvement in mitral flow dynamics during exercise after percutaneous transvenous mitral commissurotomy. Noninvasive evaluation using continuous wave Doppler technique.
Authors: JTamai, SNagata, MAkaike, FIshikura, KKimura, MTakamiya, KMiyatake, YNimura
Journal: Circulation (1990)

Evaluation of mitral flow dynamics during exercise is critically important in patients who receive percutaneous transvenous mitral commissurotomy (PTMC) because limited mitral flow during exercise provokes hemodynamic deterioration and involves cardiogenic symptoms in patients with mitral stenosis. To examine mitral flow dynamics during exercise, we applied continuous wave Doppler technique in 20 patients with mitral stenosis. Exercise Doppler study was performed 2 days before and 5 days after PTMC. PTMC increased mitral valve area from 1.0 +/- 0.3 (mean +/- SD) to 1.9 +/- 0.5 cm2 and decreased mean transmitral pressure gradient from 8 +/- 2 to 4 +/- 1 mm Hg at rest. Moreover, PTMC decreased mean transmitral pressure gradient from 21 +/- 6 to 11 +/- 4 mm Hg at submaximal exercise. The extent of an increase in mitral valve area by PTMC correlated with a decrease in the mean transmitral pressure gradient at the submaximal exercise (r = -0.76, p less than 0.01) and that at rest (r = -0.52, p less than 0.05)....
Effects of intravenous adenosine on antegrade refractoriness of accessory atrioventricular connections.
Authors: C JGarratt, M JGriffith, SO'Nunain, D EWard, A JCamm
Journal: Circulation (1991)

BACKGROUNDSeveral groups have suggested the use of intravenous adenosine or adenosine triphosphate in the diagnosis of regular broad complex tachycardias. However, the short half-life of these agents has precluded assessment of their effects on refractoriness of accessory connections, and their safety in preexcited arrhythmias has not been demonstrated.METHODS AND RESULTSWe examined the effects of intravenous adenosine on accessory atrioventricular (AV) connections in 30 patients with the Wolff-Parkinson-White syndrome. Intravenous adenosine (12 mg, rapid bolus) was administered to 14 patients (group 1) during continuous atrial pacing at a cycle length 20 msec below that required to cause 2:1 conduction block in the accessory connection (mean pacing cycle length 261 +/- 41 msec). After adenosine, transient 1:1 conduction occurred via the accessory connection in 12 of 14 patients, indicating a shortening of antegrade refractoriness. In three of seven patients, this effect was abolished after intravenous pr...
Hydrogen peroxide-induced cardiovascular reflexes. Role of hydroxyl radicals.
Authors: G LStahl, BHalliwell, J CLonghurst
Journal: Circulation Research (1992)

Mesenteric ischemia reflexly activates the cardiovascular system. In addition, mesenteric ischemia and reperfusion generate reactive oxygen species. However, the ability of these short-lived reactive oxygen species to generate cardiovascular reflexes is unknown. We therefore investigated cardiovascular reflexes induced by serosal application of hydrogen peroxide (H2O2) to the gallbladder, stomach, or duodenum in anesthetized cats. Serosal application of hydrogen peroxide (44 mumols) to the gallbladder (n = 14) significantly (p less than 0.05) increased mean arterial blood pressure (MAP) by 37 +/- 6 mm Hg, left ventricular dP/dt by 1,893 +/- 416 mm Hg/sec, heart rate by 6 +/- 1 beats per minute, and systemic vascular resistance from 0.34 +/- 0.01 to 0.42 +/- 0.04 peripheral resistance units. The cardiovascular effects were dose-dependent over a range of 0.4 pmol to 132 mumols H2O2. Celiac and superior mesenteric ganglionectomy abolished H2O2-induced cardiovascular effects. Dimethylthiourea (10 mg/kg), a re...
Residual Fatigue and Cognitive Deficits in Patients After Leucine-Rich Glioma-Inactivated 1 Antibody Encephalitis
Authors: Sophie N. M. Binks, Michele Veldsman, Ava Easton, M. Isabel Leite, David Okai, Masud Husain, Sarosh R. Irani
Journal: JAMA Neurology (2021)
HMGA2 Gene Expression Profile Improves Risk Stratification in Acute Myeloid Leukemia
Authors: Miriam Marquis, Cyrielle Beaubois, Vincent-Philippe Lavallee, Michal Abrahamowicz, Coraline Danieli, Sébastien Lemieux, Imran Ahmad, Andrew Wei, Stephen B Ting, Shaun Fleming, Anthony P Schwarer, William Grey, David Grimwade, Robert K. Hills, Paresh Vyas, Nigel H. Russell, Guy Sauvageau, Josee Hebert
Journal: Blood (2017)
Comparative systemic and regional hemodynamic effects of dopamine and dobutamine in patients with cardiomyopathic heart failure.
Authors: C VLeier, P THeban, PHuss, C ABush, R PLewis
Journal: Circulation (1978)

Thirteen patients with severe cardiac failure underwent a single crossover study of dopamine and dobutamine in order to compare the systemic and regional hemodynamic effects of the two drugs. The dose-response data demonstrated that dobutamine (2.5--10 microgram/kg/min) progressively and predictably increases cardiac output by increasing stroke volume, while simultaneously decreasing systemic and pulmonary vascular resistance and pulmonary capillary wedge pressure. There was no change in heart rate or premature ventricular contractions (PVCs)/min at this dose range. Dopamine (2--8 microgram/kg/min) increased the stroke volume and cardiac output at 4 microgram/kg/min. Dopamine at less than 4 microgram/kg/min provided little additional increase in cardiac output and increased the pulmonary wedge pressure and the number of PVCs/min. At greater than 6 microgram/kg/min, dopamine increased heart rate. During the 24-hour maintenance-dose infusion of each drug (dopamine 3.7--4, dobutamine 7.3--7.7 microgram/kg/mi...
Using Data and Modeling to Understand the Risks of In-Person Education
Authors: Andrea Ciaranello, Taison Bell
Journal: JAMA Network Open (2021)

David Naimark, MD, MSc; Sharmistha Mishra, MD, PhD; Kali Barrett, MD, MSc; Yasin A. Khan, MD; Stephen Mac, MBiotech; Raphael Ximenes, PhD; Beate Sander, RN, MBA, MEcDev, PhD
Mitral valve prolapse.
Authors: R BDevereux, J KPerloff, NReichek, M EJosephson
Journal: Circulation (1976)

For half a century the systolic click and late systolic murmur lay dormant as innocent auscultatory curiosities. The thirteen years since Barlow related these phenomena to mitral leaflet prolapse have witnessed an astonishing information explosion. We have sought to bring together the accumulated data in this review. An Historical Perspective traces the evolution from the now abandoned pericardial or extracardiac phases, through the leafletchordal phase (redundancy), the myocardial phase (segmental left ventricular contraction abnormalities), to the anular phase (dilatation and faulty systolic contraction). Functional Anatomy is dealt with in terms of pathology, pathophysiology, hemodynamics, angiocardiography, echocardiography, and physical and pharmacological interventions. Clinical Manifestations are concerned with prevalence, natural history, symptoms, physical signs, electrocardiographic abnormalities and roentgen fingings. The four Major Complications- sudden death, infective endocarditis, spont...
Natural history of chronic second-degree atrioventricular nodal block.
Authors: BStrasberg, FAmat-Y-Leon, R CDhingra, EPalileo, SSwiryn, RBauernfeind, CWyndham, K MRosen
Journal: Circulation (1981)

This report details our experience with documented chronic second-degree atrioventricular (AV) nodal block (proximal to His [H]) in 56 patients. Forty-six men (82%) and 10 women (18%), ages 18-87 years, were studied. Nineteen of the patients (34%) had no organic heart disease (including seven trained athletes) and 37 (66%) had organic heart disease. ECGs in all patients demonstrated episodes of type I second-degree block; five patients also had periods of 2:1 block. Prospective follow-up patients with no organic heart disease (157-2280 days, mean 1395 +/- 636 days) revealed one patient with clear indication for permanent pacing because of bradyarrhythmic symptoms (permanently placed on day 220 of follow-up). Two patients died nonsuddenly. In patients with organic heart disease (prospective follow-up of 60-2950 days, mean 1347 +/- 825 days), pacemakers were implanted in 10 patients, primarily for treatment of congestive heart failure in eight and syncope in two. Sixteen patients died -- three suddenly, sev...
Endogenous adenosine restrains renin release in conscious rats.
Authors: C JKuan, J NWells, E KJackson
Journal: Circulation Research (1990)

The purpose of this study was to test the hypothesis that endogenous adenosine functions to restrain the renin release response to pharmacological and pathophysiological stimuli. To achieve this objective, we examined the effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl)xanthine (DPSPX), on the renin release response induced by acute administration of hydralazine or by chronic clipping of the left renal artery (renovascular hypertensive rats). In conscious, unrestrained rats, DPSPX significantly increased plasma renin activity (PRA) in control rats, in rats treated with hydralazine, and in renovascular hypertensive rats. The effect of DPSPX on PRA was significantly greater in rats treated with hydralazine or in renovascular hypertensive rats compared with control rats. DPSPX did not influence arterial blood pressure in any group, did not affect the measurement of PRA, and did not alter the elimination of renin activity from the circulation. Additional experiments were performed i...
Hypoxia induces apoptosis with enhanced expression of Fas antigen messenger RNA in cultured neonatal rat cardiomyocytes.
Authors: MTanaka, HIto, SAdachi, HAkimoto, TNishikawa, TKasajima, FMarumo, MHiroe
Journal: Circulation Research (1994)

We examined whether apoptosis occurs in cardiomyocytes by hypoxia in vitro. Neonatal rat cardiomyocytes and nonmyocytes were cultured in 95% N2-5% CO2 atmosphere to produce hypoxic conditions. DNA fragmentation into integer multiples of the internucleosomal DNA length was observed in cardiomyocytes as early as 12 hours, whereas nonmyocytes did not show fragmentation of DNA up to 72 hours. DNA fragmentation of cardiomyocytes induced by hypoxia was also confirmed by nick-end labeling in situ. Messenger RNA for Fas antigen, a mediator of apoptotic cell death, was expressed in both cardiomyocytes and nonmyocytes as revealed by Northern blotting and in situ hybridization. In hypoxic condition, Fas messenger RNA levels in cardiomyocytes were upregulated by twofold over controls, whereas those of nonmyocytes were downregulated. These results indicate that cardiomyocyte death by hypoxia can occur via apoptosis and that Fas antigen may be associated with the mechanism of this apoptotic process.
The relationship of afterload to ejection performance in chronic mitral regurgitation.
Authors: W JCorin, E SMonrad, TMurakami, HNonogi, O MHess, H PKrayenbuehl
Journal: Circulation (1987)

Simultaneous left ventricular micromanometry and biplane cineangiography were performed in nine control subjects (group 1), 14 patients with chronic mitral regurgitation and an ejection fraction of 57% or greater (group 2), and 13 patients with mitral regurgitation and an ejection fraction of less than 57% (group 3). End-diastolic volume index was increased in both groups with mitral regurgitation (p less than .001) compared with the control group. Left ventricular end-diastolic wall thickness did not differ among the three groups, but the left ventricular muscle mass index was greater in both groups with mitral regurgitation than in controls (p less than .001). End-diastolic pressure was elevated in both groups 2 and 3 compared with group 1 (p less than .05), but peak systolic, mean systolic, and incisural pressure were not different among the three groups. End-diastolic stress was larger in groups 2 and 3 than in group 1 (p less than .05). Muscle fiber stretch was greater in group 2 than in the control ...
Congenital left ventricular inflow obstruction evaluated by two-dimensional echocardiography.
Authors: A RSnider, C LRoge, N BSchiller, N HSilverman
Journal: Circulation (1980)

Several forms of congenital heart disease that cause left ventricular inflow obstruction have similar M-mode findings, and frequently the exact anatomic diagnosis cannot be made by M-mode echocardiography alone. We examined five children with various forms of left ventricular inflow obstruction using two-dimensional echocardiography. The diagnosis was confirmed by cardiac catheterization and surgery in all five patients. In one patient with congenital mitral valve stenosis, a thick mitral valve with two papillary muscles was imaged. This patient was easily distinguished from a second child with parachute deformity of the mitral valve in whom a single papillary muscle arising from the left ventricular apex was seen. These two patients with mitral valve stenosis were easily differentiated from the three patients in whom the left ventricular inflow obstruction was caused by a membrane within the left atrium. The membrane could be seen in several spatial planes; however, we could not distinguish by two-dimens...
Intravenous Fluosol in the treatment of acute myocardial infarction. Results of the Thrombolysis and Angioplasty in Myocardial Infarction 9 Trial. TAMI 9 Research Group.
Authors: T CWall, R MCaliff, JBlankenship, J DTalley, MTannenbaum, MSchwaiger, GGacioch, M DCohen, MSanz, J DLeimberger
Journal: Circulation (1994)

BACKGROUNDThis study was performed to determine the safety and potential efficacy of an intravenous perfluorochemical emulsion (Fluosol) as an adjunct reperfusion therapy aimed at preventing reperfusion injury for patients with acute myocardial infarction.METHODS AND RESULTSPatients (430) were randomized in a prospective open-labeled study, 213 to receive Fluosol and 217 to receive no Fluosol, along with 100 mg of tissue-type plasminogen activator given over 3 hours. Major end points included global ejection fraction, regional wall motion analysis, infarct size as measured by tomographic thallium imaging, and a composite clinical outcome measure. Baseline patient and angiographic characteristics were similar in the two groups. No significant difference in global ejection fraction (52% without Fluosol, 51% with Fluosol) or regional wall motion (-2.4 SD/chord with Fluosol, -2.2 SD/chord without Fluosol) was demonstrated in patients receiving Fluosol versus those not receiving Fluosol, nor was there a signif...