tbuckley/cabot-search huggingface dataset:
Improvement in early saphenous vein graft patency after coronary artery bypass surgery with antiplatelet therapy: results of a Veterans Administration Cooperative Study.
Authors: SGoldman, JCopeland, TMoritz, WHenderson, KZadina, TOvitt, JDoherty, RRead, EChesler, YSako
Journal: Circulation (1988)

To determine whether specific antiplatelet therapies improved vein graft patency after coronary artery bypass grafting (CABG) we compared (1) aspirin, 325 mg daily, (2) aspirin, 325 mg three times daily, (3) aspirin plus dipyridamole (325 mg and 75 mg, respectively, three times daily), (4) sulfinpyrazone (267 mg three times daily), and (5) placebo (three times daily). Therapy, except aspirin, was started 48 hr before CABG. When aspirin was a treatment, one 325 mg dose was given 12 hr before surgery and therapy was maintained thereafter according to the assigned regimen. Angiographic graft patency data were obtained within 60 days of surgery. Analysis of early graft patency in 555 patients (1781 grafts), revealed the following graft patency rates: aspirin daily, 93.5%; aspirin three times daily, 92.3%; aspirin and dipyridamole, 91.9%; and sulfinpyrazone, 90.2%. All aspirin-containing therapeutic regimens improved (p less than .05) graft patency compared with placebo (85.2%). Chest tube drainage measured wi...
Ca++ distribution after Na+ pump inhibition in cultured neonatal rat myocardial cells.
Authors: J MBurt, G ALanger
Journal: Circulation Research (1982)

The influence of inhibition of the Na+ pump, with secondary stimulation of Na+-Ca++ exchange, on cellular Ca++ distribution is examined using the on-line scintillation disk technique and cultured neonatal rat myocardial cells. Under control conditions, La+++ displaced 78.1 +/- 1.13% (SEM) of the total cell associated 45Ca. Application of 1 mm ouabain or reduction of [K+]o to 0.5 mM resulted in a net increase of 10.6 +/- 1.3% and 13.8 +/- 2%, respectively, in total cell-associated Ca++. Of this added 45Ca, 75.9 +/- 2.7% and 78.4 +/- 2.1%, respectively remained La+++-displaceable. The 45Ca-binding characteristics of isolated sarcolemma, prepared from the cultured neonatal rat myocardial cells using the gas dissection technique, were examined. When treated with either ouabain or low [K+]o solutions, sarcolemmal 45Ca binding did not change. This result indicates that functional, intact tissue is necessary to observe the Ca++ increase. Treatment of the cells with verapamil before and during ouabain exposure fa...
Associations of the HDL2 and HDL3 cholesterol subfractions with the development of ischemic heart disease in British men. The Caerphilly and Speedwell Collaborative Heart Disease Studies.
Authors: P MSweetnam, C HBolton, J WYarnell, DBainton, I ABaker, P CElwood, N EMiller
Journal: Circulation (1994)

BACKGROUNDThe relative importance of HDL2 and HDL3 cholesterol as risk factors for ischemic heart disease (IHD) is still uncertain. Their associations with the incidence of IHD in the Caerphilly and Speedwell prospective studies are described.METHODS AND RESULTSThe two studies have a common core protocol and are based on a total of 4860 middle-aged men from the general population. The first follow-up was at a nearly constant interval of 5.1 years in Caerphilly and 3.2 years in Speedwell: 251 major IHD events had occurred. Lipid levels were measured on fasting samples. Different laboratories were used by the two studies. Each laboratory used ultracentrifugation to separate HDL2 and HDL3. Both subfractions were inversely associated with risk of IHD. Standardized relative odds of developing major IHD were 0.95 (95% confidence interval [CI], 0.80 to 1.14) for HDL2 cholesterol and 0.83 (95% CI, 0.68 to 1.00) for HDL3 cholesterol in Caerphilly and 0.76 (95% CI, 0.57 to 1.01) for HDL2 and 0.64 (95% CI, 0.49 to 0...
Chronic one-kidney hypertension in rabbits. III. Renopressin, a new hypertensive substance.
Authors: L TSkeggs, J RKahn, MLevine, F EDorer, K ELentz
Journal: Circulation Research (1977)

The blood pressure of rabbits with chronic one-kidney hypertension can be lowered to normal by immunization with hog kidney cortex preparations that do not contain renin, thus providing evidence for a new factor essential for the maintenance of an elevated blood pressure. A search for the new factor has led to the discovery of a hypertensive substance which we have named renopressin. Subcutaneous injection of the new substance into normal rabbits produces a delayed, slow increase in blood pressure, and after a few days the development of a moderate hypertension which persists indefinitely. The response of the blood pressure to renopressin is totally unlike that to renin. While the pressor action of renin can be blocked by an angiotensin II antagonist, the hypertension caused by renopressin cannot. Renin can increase the blood pressure of hypertensive rabbits; renopressin has no effect. The blood pressure of hypertensive rabbits and of normal rabbits made hypertensive by injection of renopressin can be low...
Contractile failure and high-energy phosphate turnover during hypoxia: 31P-NMR surface coil studies in living rat.
Authors: J ABittl, J ABalschi, J SIngwall
Journal: Circulation Research (1987)

Cardiac failure appears rapidly during severe hypoxia and precedes a substantial reduction in adenosine triphosphate content. Reduced adenosine triphosphate turnover, in the presence of nearly normal content, may be the metabolic basis for contractile failure during hypoxia. To measure both the myocardial content and the turnover rates of high-energy phosphate compounds during hypoxia, we performed 31P-nuclear magnetic resonance studies by placing a surface coil directly over the left ventricle in intubated rats that were instrumented for hemodynamic measurements and ventilated with either 21, 10, or 8% O2. Normoxia produced a hemodynamic and metabolic steady state for 4 hours and hypoxia for at least 60 minutes. Under normoxic ventilation (n = 10, mean +/- SD), the arterial PO2 was 96 +/- 14, pH 7.38 +/- 0.11, and systolic blood pressure 96 +/- 8 mm Hg; under hypoxic ventilation with 10% O2 (n = 5), the arterial PO2 was 57 +/- 10, pH 7.39 +/- 0.09, and systolic pressure 68 +/- 10; and under hypoxic venti...
Inter-Observer Agreement of the Paris and the Simplified Classifications of Superficial Colonic Lesions: A Western Study
Authors: F Cocomazzi, M Gentile, F Perri, A Merla, F Bossa, M Piazzolla, A Ippolito, F Terracciano, AP Giuliani, R Cubisino, A Marra, S Carparelli, A Mileti, R Paolillo, A Fontana, M Copetti, Leo A Di, A Andriulli
Journal: Endoscopy (2021)

Aims The Paris classification of superficial colonic lesions is widely adopted, but a simplified description which subgroups the shape into pedunculated, sessile/flat and depressed lesions has been proposed recently. To evaluate accuracy and inter-rater agreement among 13 Western endoscopists for the two classification systems.
Sustained bundle branch reentry as a mechanism of clinical tachycardia.
Authors: JCaceres, MJazayeri, JMcKinnie, BAvitall, S TDenker, PTchou, MAkhtar
Journal: Circulation (1989)

The incidence of sustained bundle branch reentrant (BBR) tachycardia as a clinical or induced arrhythmia or both continues to be underreported. At our institution, BBR has been the underlying mechanism of sustained monomorphic ventricular tachycardia in approximately 6% of patients, whereas mechanisms unrelated to BBR were the cause in the rest. Data gathered from 20 consecutive patients showed electrophysiologic characteristics that suggest this possibility. These include induction of sustained monomorphic tachycardia with typical left or right bundle branch block morphology or both and atrioventricular dissociation or ventriculoatrial block. On intracardiac electrograms, all previously published criteria for BBR were fulfilled, and in addition, whenever there was a change in the cycle length of tachycardia, the His to His cycle length variation produced similar changes in ventricular activation during subsequent complexes with no relation to the preceding ventricular activation cycles. Compared with pat...
Initial experience with a direct antithrombin, Hirulog, in unstable angina. Anticoagulant, antithrombotic, and clinical effects.
Authors: R MLidón, PThéroux, MJuneau, BAdelman, JMaraganore
Journal: Circulation (1993)

BACKGROUNDCurrently available antithrombotic therapy for unstable angina is unwieldy and occasionally ineffective. This study was designed to investigate the potential of Hirulog, a new synthetic specific antithrombin agent, for the management of this condition.METHODS AND RESULTSA total of 55 patients in the acute phase of unstable angina received intravenous Hirulog according to one of two protocols. In an acute dose-escalating study, 0.02, 0.05, 0.1, 0.25, and 0.5 mg.kg-1 x h-1, each for 30 minutes, were infused in 15 patients. Prolongation of activated partial thromboplastin time (aPTT) (r = .95), fibrinopeptide A inhibition (r = .96), and Hirulog plasma levels (r = .91) correlated closely with the dose infused, with significant changes compared with baseline appearing at doses of 0.25 mg.kg-1 x h-1 and higher. The purposes of the second protocol were to determine whether the anticoagulant and antithrombotic effects of the drug were sustained during a 72-hour infusion and to assess whether such treatm...
Regional myocardial volume perfused by the coronary artery branch: estimation in vivo.
Authors: YKoiwa, R CBahn, E LRitman
Journal: Circulation (1986)

Seven closed-chest dogs were anesthetized with intramuscular Innovar and a N2O/O2 gas mixture. Maximal coronary vasodilation was induced by intra-aortic injection of nitroglycerin (200 micrograms/kg) and continuous infusion of adenosine (1 mg/kg/min) into the main pulmonary artery. Superselective coronary arteriograms were obtained at varying distances along the left circumflex and left anterior descending coronary arteries during scans using the dynamic spatial reconstructor rapid tomographic x-ray scanner. At end-diastole the images of the coronary arteries and opacified myocardium were analyzed for cross-sectional area (CSA) of the coronary artery lumen and regional myocardial volume (Vdsr) perfused by that coronary artery. Postmortem regional myocardial volume (Vpath) was related to the volume perfused by the same artery measured in vivo by the dynamic spatial reconstructor as follows: Vdsr = 4.56 + 0.93 Vpath (r = .98, p less than .001). In addition, the cross-sectional area of the coronary artery su...
Length-dependent calcium inotropism in cat papillary muscle.
Authors: L LHuntsman, D KStewart
Journal: Circulation Research (1977)

We studied changes in the relationship of isometric developed force to muscle length when extracellular calcium concentration was altered in isolated cat papillary muscles. In two series of experiments at temperatures of 30 degrees C and 32 degrees C, and rates of 12 and 30 beats/min, 21 muscles were exposed to calcium concentrations of 1.125, 2.25 and 4.5 mM. Muscle lengths were varied between 80% and 100% of the length at which maximum developed force occurred (Lmax). Peak developed force and the time from stimulus to peak were measured. The data indicate that force is not altered proportionately at all lengths when calcium concentration is changed. Rather, we found that a substantially greater modification of force occurs at short lengths than at long lengths. Similarly, the time to peak force increases with length at a rate which is more than 4 times greater at the low calcium concentration than it is at the high concentration. Small but consistent shifts of Lmax also are seen. We observed that Lmax i...
Localized arterial wall drug delivery from a polymer-coated removable metallic stent. Kinetics, distribution, and bioactivity of forskolin.
Authors: T LLambert, VDev, ERechavia, J SForrester, FLitvack, N LEigler
Journal: Circulation (1994)

BACKGROUNDCoronary stenting is associated with two major complications: subacute thrombosis and neointimal proliferation resulting in restenosis. Our hypothesis is that the biocompatibility of metallic stents can be improved by coating with a polymer membrane that delivers agents that favorably modify the local arterial microenvironment. This study evaluates the kinetics, distribution, and bioactivity of the model drug forskolin delivered to the local arterial wall by a polyurethane-coated removable metallic stent.METHODS AND RESULTSStents were used in rabbit carotid arteries (n = 20) for as long as 24 hours. The quantity of forskolin bound to the stent decreased exponentially with a half-life of 5.8 hours. Blood concentrations peaked at 140 +/- 39 pg/microL at 4 hours. The adjacent arterial media contained 60 +/- 39 ng/mg, which was 380- and 460-fold greater than the contralateral carotid media and the systemic blood, respectively (P < .0001). Media forskolin concentrations declined exponentially over ti...
Sotalol versus quinidine for the maintenance of sinus rhythm after direct current conversion of atrial fibrillation.
Authors: SJuul-Möller, NEdvardsson, NRehnqvist-Ahlberg
Journal: Circulation (1990)

This open, parallel-group study compares quinidine and sotalol treatment for maintenance of sinus rhythm after direct current conversion of patients with chronic atrial fibrillation. The patients from 15 centers in Sweden were randomized to sotalol (98 patients) or quinidine (85 patients) after 2 hours of sinus rhythm after direct current conversion. According to primary efficacy assessment, 52% of the patients in the sotalol group and 48% of the patients in the quinidine group remained in sinus rhythm during the following 6-month treatment period (NS). Furthermore, 34% of the patients treated with sotalol and 22% of the patients treated with quinidine relapsed into atrial fibrillation (NS). Heart rate after relapsing into atrial fibrillation was higher in the patients treated with quinidine (109 beats/min) than in the patients treated with sotalol (78 beats/min, p less than 0.001). Patients treated with sotalol were found to be less symptomatic at the time of relapse compared with relapsing patients in t...
Levosimendan Improves Hemodynamics and Exercise Tolerance in PH-HFpEF
Authors: Daniel Burkhoff, Barry A. Borlaug, Sanjiv J. Shah, Ronald Zolty, Ryan J. Tedford, Thenappan Thenappan, Roham T. Zamanian, Jeremy A. Mazurek, Jonathan D. Rich, Marc A. Simon, Eugene S. Chung, Farhan Raza, David T. Majure, Gregory D. Lewis, Ioana R. Preston, Stuart Rich
Journal: JACC Heart Failure (2021)

The purpose of this study was to evaluate the effects of intravenous levosimendan on hemodynamics and 6-min walk distance (6MWD) in patients with pulmonary hypertension and heart failure with preserved ejection fraction (PH-HFpEF). There are no proven effective treatments for patients with PH-HFpEF. Patients with mean pulmonary artery pressure (mPAP) ≥35 mm Hg, pulmonary capillary wedge pressure (PCWP) ≥20 mm Hg, and LVEF ≥40% underwent 6MWD and hemodynamic measurements at rest, during passive leg raise, and supine cycle exercise at baseline and after an open-label 24-h levosimendan infusion (0.1 μg/kg/min). Hemodynamic responders (those with ≥4 mm Hg reduction of exercise-PCWP) were randomized (double blind) to weekly levosimendan infusion (0.075 to 0.1 ug/kg/min for 24 h) or placebo for 5 additional weeks. The primary end point was exercise-PCWP, and key secondary end points included 6MWD and PCWP measured across all exercise stages. Thirty-seven of 44 patients (84%) met responder criteria and were randomized to levosimendan (n = 18) or placebo (n = 19). Participants were 69 ± 9 years of age, 61% female, and with resting mPAP 41.0 ± 9.3 mm Hg and exercise-PCWP 36.8 ± 11.3 mm Hg. Compared with placebo, levosimendan did not significantly reduce the primary end point of exercise-PCWP at 6 weeks (−1.4 mm Hg; 95% confidence interval [CI]: −7.8 to 4.8; p = 0.65). However, levosimendan reduced PCWP measured across all exercise stages (−3.9 ± 2.0 mm Hg; p = 0.047). Levosimendan treatment resulted in a 29.3 m (95% CI: 2.5 to 56.1; p = 0.033) improvement in 6MWD compared with placebo. Six weeks of once-weekly levosimendan infusion did not affect exercise-PCWP but did reduce PCWP incorporating data from rest and exercise, in tandem with increased 6MWD. Further study of levosimendan is warranted as a therapeutic option for PH-HFpEF. (Hemodynamic Evaluation of Levosimendan in Patients With PH-HFpEF [HELP]; NCT03541603)
Poetry and Medicine
Authors: Elisavietta Ritchie
Journal: JAMA (1990)

Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA HomeNew OnlineCurrent IssueFor Authors Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA journal
Restrictive cardiomyopathy versus constrictive pericarditis: role of endomyocardial biopsy in avoiding unnecessary thoracotomy.
Authors: M HSchoenfeld, E WSupple, G WDec, J TFallon, I FPalacios
Journal: Circulation (1987)

Despite careful clinical, noninvasive, and hemodynamic assessment of patients with constrictive/restrictive physiology, the differentiation of restrictive cardiomyopathy from constrictive pericarditis remains difficult. We examined the role of right ventricular endomyocardial biopsy in defining the underlying process in 54 patients with evidence of constrictive/restrictive physiology, including 38 patients with profound symptoms of heart failure in whom diagnostic/therapeutic thoracotomy was contemplated (group I) and 16 patients with milder symptoms (group II). All patients in group I had NYHA class III or IV heart failure with depressed cardiac index (mean 2.5 liters/min/m2), right atrial hypertension (mean 15 mm Hg), and normal left ventricular ejection fraction (mean 59%). Endomyocardial biopsy identified a specific source of restrictive cardiomyopathy in 15 of 38 patients (39%) (11 amyloid, four myocarditis). Of the 23 remaining patients with either normal biopsy findings or nonspecific abnormalities...
Comparative effects of chronic angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade on cardiac remodeling after myocardial infarction in the rat.
Authors: BSchieffer, AWirger, MMeybrunn, SSeitz, JHoltz, U NRiede, HDrexler
Journal: Circulation (1994)

BACKGROUNDAfter myocardial infarction, the noninfarcted left ventricle develops reactive hypertrophy associated with a depressed coronary flow reserve, myocardial interstitial fibrosis, and reduced capillary density. The present study investigated the comparative cardiac effects of chronic angiotensin-converting enzyme (ACE) inhibition and selective angiotensin II type 1 receptor (AT1) blockade in the rat model of myocardial infarction and failure.METHODS AND RESULTSSeven days after coronary ligation (MI), rats were randomized to enalapril (n = 8; 500 micrograms.kg-1.d-1), losartan (n = 9; 3 mg.kg-1.d-1), or placebo (n = 8) and treated for 6 weeks. Sham-operated rats (n = 10) served as controls. Coronary blood flow was measured with radiolabeled microspheres during baseline and maximal coronary dilation induced by dipyridamole (2 mg.kg-1.min-1 over 10 minutes). Right and left ventricular (LV) weight was increased in infarcted rats compared with sham-operated animals and enalapril- and losartan-treated MI ...
Relationship between plasma lipid concentrations and coronary artery disease in 496 patients.
Authors: A MGotto, G AGorry, J RThompson, J SCole, RTrost, DYeshurun, M EDeBakey
Journal: Circulation (1977)

The relationship between fasting plasma cholesterol and triglyceride concentrations and the frequency and extensiveness of coronary artery disease (CAD) was studied in 496 subjects evaluated for chest pain by coronary arteriography at The Methodist Hospital. One hundred six of the patients had no CAD while 390 had 25% or greater stenosis of one or more major vessels. Ninety-one percent had 75% or greater stenosis of at least one major vessel. Mean age for the group with CAD was 55.7 +/- 8.7 and without disease 49.4 +/- 11.6 (P less than 0.01). Both cholesterol and triglyceride concentrations were higher (P less than 0.001) in the group with CAD. Mean cholesterol concentration in males increased from 195 +/- 36 mg/dl in the group without CAD to 219 +/- 41 in the group with three vessel disease and in females from 207 +/- 40 to 252 +/- 42. A progressive increase in triglyceride values was also detected but was less consistent. At the level of 25% and greater obstruction, the partial correlation coefficients...
Distribution of myocardial blood flow in the exercising dog with restricted coronary artery inflow.
Authors: R MBall, R JBache
Journal: Circulation Research (1976)

The effect of a proximal coronary artery stenosis on transmural myocardial blood flow during exercise was studied in nine dogs with electromagnetic flowmeter probes and hydraulic occluders on the left circumflex coronary artery. Regional myocardial blood flow at rest and during treadmill exercise was estimated with radioactive microspheres 7-10 mum in diameter. Exercise studies were performed during unrestricted coronary artery inflow (control exercise) and during partial inflation of the occluder to a level which did not reduce flow at rest but which limited the increase in flow during exercise to 66 +/- 6% (mild restriction) or 44 +/- 3% (severe restriction) of the value during control exercise. Mean myocardial blood flow at rest was 0.94 +/- 0.06 ml/min per g of myocardium and increased to 2.45 +/- 0.15 ml/min per g during control exercise, with uniform distribution across the wall of the left ventricle. Flow to the subepicardial myocardium was significantly greater during exercise in the presence of a...