Endogenous circadian rhythm in vasovagal response to head-up tilt.


BACKGROUND:The incidence of syncope exhibits a daily pattern with more occurrences in the morning, possibly as a result of influences from the endogenous circadian system and/or the daily pattern of behavioral/emotional stimuli. This study tested the hypothesis that the circadian system modulates cardiovascular responses to postural stress, leading to increased susceptibility to syncope at specific times of day. METHODS AND RESULTS:Twelve subjects underwent a 13-day in-laboratory protocol in which subjects' sleep-wake cycles were adjusted to 20 hours for 12 cycles. A 15-minute tilt-table test (60° head-up) was performed ≈4.5 hours after scheduled awakening in each cycle so that 12 tests in each subject were distributed evenly across the circadian cycle. Of 144 tests, signs/symptoms of presyncope were observed in 21 tests in 6 subjects. These presyncope events displayed a clear circadian rhythm (P=0.028) with almost all cases (17/21) occurring in the half of the circadian cycle corresponding to the biological night (10:30 pm to 10:30 am). Significant circadian rhythms were also observed in hemodynamic and autonomic function markers (blood pressure, heart rate, epinephrine, norepinephrine, and indices of cardiac vagal tone) that may underlie the circadian rhythm of presyncope susceptibility. CONCLUSIONS:The circadian system affects cardiovascular responses to postural stress, resulting in greater susceptibility to presyncope during the night. This finding suggests that night-shift workers and people with disrupted sleep at night may have greater risk of syncope as a result of their exposure to postural stress during the biological night.






Hu K,Scheer FA,Laker M,Smales C,Shea SA




Has Abstract


2011-03-08 00:00:00














  • Inhaled nitric oxide versus aerosolized iloprost in secondary pulmonary hypertension in children with congenital heart disease: vasodilator capacity and cellular mechanisms.

    abstract:BACKGROUND:Inhaled nitric oxide (iNO) has been used to assess the vasodilator capacity of the pulmonary vascular bed in children with congenital heart disease and elevated pulmonary vascular resistance. Inhaled iloprost is a pulmonary vasodilator for the long-term treatment of pulmonary hypertension (PHT). Because thes...


    pub_type: 临床试验,杂志文章


    authors: Rimensberger PC,Spahr-Schopfer I,Berner M,Jaeggi E,Kalangos A,Friedli B,Beghetti M

    更新日期:2001-01-30 00:00:00

  • Coronary angioplasty performed within the thrombolysis in Myocardial Infarction II study.

    abstract:BACKGROUND:Percutaneous transluminal coronary angioplasty (PTCA) of the infarct-related artery was performed within 42 days of recombinant tissue-type plasminogen activator (rt-PA) administration in 1,414 of the 3,534 patients who participated in the Thrombolysis In Myocardial Infarction (TIMI) II study. Primary angiog...


    pub_type: 杂志文章


    authors: Baim DS,Diver DJ,Feit F,Greenberg MA,Holmes DR,Weiner BH,Williams DO,Schweiger MJ,Brown BG,Frederick MM

    更新日期:1992-01-01 00:00:00

  • Exercise echocardiography versus 201Tl single-photon emission computed tomography in evaluation of coronary artery disease. Analysis of 292 patients.

    abstract:BACKGROUND:Exercise echocardiography (digital cine-loop technique) and 201Tl single-photon emission computed tomography (SPECT) were performed simultaneously in 292 patients being evaluated for coronary artery disease. METHODS AND RESULTS:Pretreadmill and posttreadmill echocardiographic images of diagnostic quality we...


    pub_type: 杂志文章


    authors: Quiñones MA,Verani MS,Haichin RM,Mahmarian JJ,Suarez J,Zoghbi WA

    更新日期:1992-03-01 00:00:00

  • Hyperlipidemia and coronary disease. Correction of the increased thrombogenic potential with cholesterol reduction.

    abstract:BACKGROUND:Hypercholesterolemia is a risk factor for coronary disease, and platelet reactivity is increased with hypercholesterolemia, suggesting a prethrombotic risk. The aim of this study was to measure mural platelet thrombus formation on an injured arterial wall in a model simulating vessel stenosis and plaque rupt...


    pub_type: 杂志文章


    authors: Lacoste L,Lam JY,Hung J,Letchacovski G,Solymoss CB,Waters D

    更新日期:1995-12-01 00:00:00

  • Long-term results of catheter ablation in paroxysmal atrial fibrillation: lessons from a 5-year follow-up.

    abstract:BACKGROUND:Paroxysmal atrial fibrillation (AF) naturally progresses toward chronic AF at an estimated rate of 15% to 30% over a 1- to 3-year period. Pulmonary vein (PV) isolation is increasingly performed for the treatment of drug-refractory paroxysmal AF. The long-term data on clinical outcome after circumferential PV...


    pub_type: 杂志文章


    authors: Ouyang F,Tilz R,Chun J,Schmidt B,Wissner E,Zerm T,Neven K,Köktürk B,Konstantinidou M,Metzner A,Fuernkranz A,Kuck KH

    更新日期:2010-12-07 00:00:00

  • Oxygenation in patients with a functionally univentricular circulation and complete mixing of blood: are saturation and flow interchangeable?

    abstract:BACKGROUND:Perioperative management of patients with complete mixing of pulmonary and systemic blood centers on approximately equating pulmonary (Qp) and systemic (Qs) blood flow (Qp/Qs approximately 1). This empirically derived target is opposed by theoretical studies advocating a target Qp/Qs well below 1. We studied...


    pub_type: 杂志文章


    authors: Francis DP,Willson K,Thorne SA,Davies LC,Coats AJ

    更新日期:1999-11-23 00:00:00

  • Forecasting the future of cardiovascular disease in the United States: a policy statement from the American Heart Association.

    abstract:BACKGROUND:Cardiovascular disease (CVD) is the leading cause of death in the United States and is responsible for 17% of national health expenditures. As the population ages, these costs are expected to increase substantially. METHODS AND RESULTS:To prepare for future cardiovascular care needs, the American Heart Asso...


    pub_type: 共识发展会议,杂志文章


    authors: Heidenreich PA,Trogdon JG,Khavjou OA,Butler J,Dracup K,Ezekowitz MD,Finkelstein EA,Hong Y,Johnston SC,Khera A,Lloyd-Jones DM,Nelson SA,Nichol G,Orenstein D,Wilson PW,Woo YJ,American Heart Association Advocacy Coordinating

    更新日期:2011-03-01 00:00:00

  • Progesterone induces human leukocyte antigen-g expression in vascular endothelial and smooth muscle cells.

    abstract:BACKGROUND:Human leukocyte antigen-G (HLA-G) expression in heart transplant patients has been negatively associated with acute cellular rejection and cardiac allograft vasculopathy. We assessed HLA-G expression in vascular human endothelial and smooth muscle cell cultures to determine if future therapeutic agents can b...


    pub_type: 杂志文章


    authors: Sheshgiri R,Rao V,Tumiati LC,Xiao R,Prodger JL,Badiwala M,Librach C,Delgado DH

    更新日期:2008-09-30 00:00:00

  • Role of functional block extension in lesion-related atrial flutter.

    abstract:BACKGROUND:A line of block in the right atrium (RA) between the venae cavae is necessary to obtain classic atrial flutter (AFL). We tested the hypothesis that the location of that line of block would determine whether the AFL reentrant circuit would be due to single-loop reentry or figure-of-8 reentry. METHODS AND RES...


    pub_type: 杂志文章


    authors: Tomita Y,Matsuo K,Sahadevan J,Khrestian CM,Waldo AL

    更新日期:2001-02-20 00:00:00

  • Endothelin 1 type a receptor antagonism prevents vascular dysfunction and hypertension induced by 11beta-hydroxysteroid dehydrogenase inhibition: role of nitric oxide.

    abstract:BACKGROUND:The enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) prevents inappropriate activation of the nonselective mineralocorticoid receptors by glucocorticoids. Renal activity of 11beta-HSD is decreased in patients with apparent mineralocorticoid excess (SAME), licorice-induced hypertension, and essential h...


    pub_type: 杂志文章


    authors: Ruschitzka F,Quaschning T,Noll G,deGottardi A,Rossier MF,Enseleit F,Hürlimann D,Lüscher TF,Shaw SG

    更新日期:2001-06-26 00:00:00

  • Augmentation of left ventricular contractility by cardiac sympathetic neural stimulation.

    abstract:BACKGROUND:Electric stimulation of mediastinal sympathetic cardiac nerves increases cardiac contractility but is not selective for the left ventricle because it elicits sinus tachycardia and enhanced atrioventricular conduction. The aim of this study was to identify sympathetic neural structures inside the heart that s...


    pub_type: 杂志文章


    authors: Meyer C,Rana OR,Saygili E,Gemein C,Becker M,Nolte KW,Weis J,Schimpf T,Knackstedt C,Mischke K,Hoffmann R,Kelm M,Pauza D,Schauerte P

    更新日期:2010-03-23 00:00:00

  • Reversal of dominance of the coronary arterial system in isolated aortic stenosis and bicuspid aortic valve.

    abstract::The dominance of the coronary arterial system was determined angiographically in 75 adult patients with isolated aortic stenosis with or without insufficiency, 25 adult patients with pure aortic insufficiency, 51 adult patients with combined aortic stenosis and mitral valve disease, and 44 children with bicuspid aorti...


    pub_type: 杂志文章


    authors: Higgins CB,Wexler L

    更新日期:1975-08-01 00:00:00

  • Effect of functional health-related quality of life on long-term survival after cardiac surgery.

    abstract:BACKGROUND:Health-related quality-of-life instruments have become important measures of early health outcomes after cardiac surgery. The relationship between quality of life after recovery from surgery and subsequent long-term survival has not previously been explored. Our objective was to determine whether the Duke Ac...


    pub_type: 杂志文章


    authors: Koch CG,Li L,Lauer M,Sabik J,Starr NJ,Blackstone EH

    更新日期:2007-02-13 00:00:00

  • Acute effects of nitrates on exercise testing in patients with syndrome X. Clinical and pathophysiological implications.

    abstract:BACKGROUND:Sublingual nitrates are much more effective in relieving angina pectoris in patients with coronary artery disease than in patients with syndrome X, but it is not known whether their effect on exercise tolerance is also different in these two groups of patients. METHODS AND RESULTS:Treadmill exercise testing...


    pub_type: 杂志文章


    authors: Lanza GA,Manzoli A,Bia E,Crea F,Maseri A

    更新日期:1994-12-01 00:00:00

  • Intracoronary adenovirus encoding adenylyl cyclase VI increases left ventricular function in heart failure.

    abstract:BACKGROUND:We tested the hypothesis that intracoronary delivery of an adenovirus encoding adenylyl cyclase type VI (Ad.AC(VI)) would be associated with increased left ventricular (LV) function in pigs with congestive heart failure. METHODS AND RESULTS:Pigs (52+/-6 kg; n=16) underwent placement of pacemakers, LV pressu...


    pub_type: 杂志文章


    authors: Lai NC,Roth DM,Gao MH,Tang T,Dalton N,Lai YY,Spellman M,Clopton P,Hammond HK

    更新日期:2004-07-20 00:00:00

  • Angiotensin-converting enzyme inhibition increases human vascular tissue-type plasminogen activator release through endogenous bradykinin.

    abstract:BACKGROUND:Angiotensin-converting enzyme (ACE) inhibition potentiates the tissue-type plasminogen activator (t-PA) response to exogenous bradykinin. This study tested the hypothesis that ACE inhibition increases endothelial t-PA release through endogenous bradykinin. METHODS AND RESULTS:We measured the effect of intra...


    pub_type: 临床试验,杂志文章,随机对照试验


    authors: Pretorius M,Rosenbaum D,Vaughan DE,Brown NJ

    更新日期:2003-02-04 00:00:00

  • The power of play: Innovations in Getting Active Summit 2011: a science panel proceedings report from the American Heart Association.

    abstract:BACKGROUND:To examine the influence active-play video gaming (also referred to as exergaming, exertainment, and active gaming) might have on improving health-related skills, enhancing self-esteem and self-efficacy, promoting social support, and ultimately motivating positive changes in health behaviors, the American He...




    authors: Lieberman DA,Chamberlin B,Medina E Jr,Franklin BA,Sanner BM,Vafiadis DK,Power of Play: Innovations in Getting Active Summit Planning Committee.

    更新日期:2011-05-31 00:00:00

  • Depression and coronary heart disease: recommendations for screening, referral, and treatment: a science advisory from the American Heart Association Prevention Committee of the Council on Cardiovascular Nursing, Council on Clinical Cardiology, Council on

    abstract::Depression is commonly present in patients with coronary heart disease (CHD) and is independently associated with increased cardiovascular morbidity and mortality. Screening tests for depressive symptoms should be applied to identify patients who may require further assessment and treatment. This multispecialty consen...


    pub_type: 杂志文章


    authors: Lichtman JH,Bigger JT Jr,Blumenthal JA,Frasure-Smith N,Kaufmann PG,Lespérance F,Mark DB,Sheps DS,Taylor CB,Froelicher ES,American Heart Association Prevention Committee of the Council on Cardiovascular Nursing.,American Heart Assoc

    更新日期:2008-10-21 00:00:00

  • Abnormalities of cardiac sympathetic function in pacing-induced heart failure as assessed by [123I]metaiodobenzylguanidine scintigraphy.

    abstract:BACKGROUND:Increased activity of the sympathetic nervous system contributes significantly to the pathophysiology of heart failure. However, cardiac efferent sympathetic function has not been well characterized in this disorder. In this study, we evaluated cardiac sympathetic innervation using [123I]metaiodobenzylguanid...


    pub_type: 杂志文章


    authors: Simmons WW,Freeman MR,Grima EA,Hsia TW,Armstrong PW

    更新日期:1994-06-01 00:00:00

  • The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials.

    abstract:BACKGROUND:Coconut oil is high in saturated fat and may, therefore, raise serum cholesterol concentrations, but beneficial effects on other cardiovascular risk factors have also been suggested. Therefore, we conducted a systematic review of the effect of coconut oil consumption on blood lipids and other cardiovascular ...


    pub_type: 杂志文章,meta分析


    authors: Neelakantan N,Seah JYH,van Dam RM

    更新日期:2020-03-10 00:00:00

  • Vascular endothelial cell growth-activated XBP1 splicing in endothelial cells is crucial for angiogenesis.

    abstract:BACKGROUND:Vascular endothelial cell growth factor plays a pivotal role in angiogenesis via regulating endothelial cell proliferation. The X-box binding protein 1 (XBP1) is believed to be a signal transducer in the endoplasmic reticulum stress response. It is unknown whether there is crosstalk between vascular endothel...


    pub_type: 杂志文章


    authors: Zeng L,Xiao Q,Chen M,Margariti A,Martin D,Ivetic A,Xu H,Mason J,Wang W,Cockerill G,Mori K,Li JY,Chien S,Hu Y,Xu Q

    更新日期:2013-04-23 00:00:00

  • Protection of endothelium in vessel segments excised for grafting.

    abstract::Contracture and collapse often complicate dissection and excision of blood vessels for grafting. Subsequent forceful redilatation and leak checking with cold saline almost always lead to partial or total denudation of endothelium, which increases the risk of early occlusion by thrombi or late occlusion by fibrocellula...


    pub_type: 杂志文章


    authors: Haudenschild C,Gould KE,Quist WC,LoGerfo FW

    更新日期:1981-08-01 00:00:00

  • Effect of surgical reduction of left ventricular outflow obstruction on hemodynamics, coronary flow, and myocardial metabolism in hypertrophic cardiomyopathy.

    abstract::To assess the impact of operative reduction of left ventricular outflow obstruction in hypertrophic cardiomyopathy, measurements of great cardiac vein flow, oxygen and lactate content, left ventricular pressures, and cardiac index were measured at rest and during pacing stress in 20 consecutive patients (13, myotomy-m...


    pub_type: 杂志文章


    authors: Cannon RO 3rd,McIntosh CL,Schenke WH,Maron BJ,Bonow RO,Epstein SE

    更新日期:1989-04-01 00:00:00

  • Fibroblast growth factor receptor-1 signaling induces osteopontin expression and vascular smooth muscle cell-dependent adventitial fibroblast migration in vitro.

    abstract:BACKGROUND:Increased expression of osteopontin (OPN), fibroblast growth factors (FGFs), and their type-1 receptor (FGFR-1) is associated with neointima formation and atherosclerosis. This study tested the hypothesis that ligand activation of FGFR-1 stimulates OPN expression in rat aortic smooth muscle cells (RASMCs), e...


    pub_type: 杂志文章


    authors: Li G,Oparil S,Kelpke SS,Chen YF,Thompson JA

    更新日期:2002-08-13 00:00:00

  • Variability, reproducibility, and applications of precordial ST-segment mapping following acute myocardial infarction.

    abstract::In 58 patients with uncomplicated acute anterior myocardial infarction, a mean decline in the sum of ST segments (sigmaST) of 34% was observed when comparing sigmaST values recorded at 3-6 hours with those recorded at 6-9 hours after the onset of symptoms (P less than 0.05). The mean absolute difference between 19 pai...


    pub_type: 杂志文章


    authors: Hardarson T,Henning H,O'Rourke RA,Karliner JS,Ryan W,Ross J Jr

    更新日期:1978-06-01 00:00:00

  • An in vivo model of experimental arterial stenosis, intimal damage, and periodic thrombosis.

    abstract::Coronary artery bypass grafts, angioplasty, and thrombolysis are beneficial procedures for patients with coronary artery disease. However, these procedures can fail by mechanisms related to interactions between platelets and the damaged arterial wall. An experimental model for studying some of the mechanisms of platel...


    pub_type: 杂志文章,评审


    authors: Folts J

    更新日期:1991-06-01 00:00:00

  • Effect of torcetrapib on glucose, insulin, and hemoglobin A1c in subjects in the Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events (ILLUMINATE) trial.

    abstract:BACKGROUND:High-density lipoproteins have antidiabetic properties in vitro. Furthermore, elevated high-density lipoprotein levels accompanying a genetic deficiency of cholesteryl ester transfer protein are associated with decreased levels of plasma glucose. We now investigate effects on glucose homeostasis of inhibitin...


    pub_type: 杂志文章,多中心研究,随机对照试验


    authors: Barter PJ,Rye KA,Tardif JC,Waters DD,Boekholdt SM,Breazna A,Kastelein JJ

    更新日期:2011-08-02 00:00:00

  • Severe pulmonary hypertension associated with a small ventricular septal defect.

    abstract::A case of progressive pulmonary hypertension in a child with a small ventricular septal defect is presented. Natural history studies have indicated that children with small ventricular septal defects can be followed conservatively. This case represents a contradiction to that rule and suggests that further study must ...


    pub_type: 杂志文章


    authors: Bisset GS 3rd,Hirschfeld SS

    更新日期:1983-02-01 00:00:00

  • Eliminating bradyarrhythmias after orthotopic heart transplantation.

    abstract:BACKGROUND:Bradycardia and sinus node dysfunction are common causes of early postoperative morbidity in orthotopic heart transplant recipients and frequently require the use of chronotropic drugs or permanent pacemakers. Several causes have been postulated, including surgical trauma to the sinus node and its blood supp...


    pub_type: 杂志文章


    authors: Rothman SA,Jeevanandam V,Combs WG,Furukawa S,Hsia HH,Eisen HJ,Buxton AE,Miller JM

    更新日期:1996-11-01 00:00:00

  • Sudden death in familial polymorphic ventricular tachycardia associated with calcium release channel (ryanodine receptor) leak.

    abstract:BACKGROUND:Familial polymorphic ventricular tachycardia (FPVT) is characterized by exercise-induced arrhythmias and sudden cardiac death due to missense mutations in the cardiac ryanodine receptor (RyR2), an intracellular Ca2+ release channel required for excitation-contraction coupling in the heart. METHODS AND RESUL...


    pub_type: 杂志文章


    authors: Lehnart SE,Wehrens XH,Laitinen PJ,Reiken SR,Deng SX,Cheng Z,Landry DW,Kontula K,Swan H,Marks AR

    更新日期:2004-06-29 00:00:00