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














  • Contrast M-mode ultrasonography of the inferior vena cava.

    abstract::Contrast M-mode and two-dimensional ultrasonography of the inferior vena cava were performed in 65 patients with various acquired and congenital cardiac disorders. After saline was injected into a peripheral arm vein, the inferior vena cava was visualized by both methods in 60 patients (92%). The M-mode approach was b...


    pub_type: 杂志文章


    authors: Wise NK,Myers S,Fraker TD,Stewart JA,Kisslo JA

    更新日期:1981-05-01 00:00:00

  • Noninvasive arterial thrombus imaging with 99mTc monoclonal antifibrin antibody.

    abstract:BACKGROUND:The T2G1s monoclonal antifibrin antibody binds specifically to fibrin but not to fibrinogen. METHODS AND RESULTS:In a canine model of acute arterial thrombosis, we determined the feasibility of imaging thrombi using a 99mTc-labeled Fab' fragment. In 14 dogs, 10 carotid and 13 femoral artery thrombi were pro...


    pub_type: 杂志文章


    authors: Cerqueira MD,Stratton JR,Vracko R,Schaible TF,Ritchie JL

    更新日期:1992-01-01 00:00:00

  • Pulmonary artery index. A nonpredictor of operative survival in patients undergoing modified Fontan repair.

    abstract::The importance of pulmonary artery size and the value of a standardized pulmonary artery index (PAI) in predicting outcome after Fontan's repair have previously been reported and questioned. We retrospectively reviewed 29 patients undergoing modified Fontan repair at The Children's Hospital of Philadelphia to examine ...


    pub_type: 杂志文章


    authors: Bridges ND,Farrell PE Jr,Pigott JD 3rd,Norwood WI,Chin AJ

    更新日期:1989-09-01 00:00:00

  • Wolff-Parkinson-White syndrome. The problem, evaluation, and surgical correction.

    abstract::Physiological studies of the type we have described, when performed in patients with the WPW syndrome, can yield diagnostic information regarding the mechanism of arrhythmia, demonstrate functional properties of therapeutic import, facilitate therapeutic decision-making about drug regimens and presumptively localize t...


    pub_type: 杂志文章


    authors: Gallagher JJ,Gilbert M,Svenson RH,Sealy WC,Kasell J,Wallace AG

    更新日期:1975-05-01 00:00:00

  • Epidemiologic study of candidates for coronary artery bypass surgery.

    abstract::Simplified estimates of the potential patients eligible for coronary artery bypass surgery are presented. Various means of identification are discussed, as well as effects of two levels of stenosis. Although ultimate operability is not directly considered, the results demonstrate a substantial and growing pool of elig...


    pub_type: 杂志文章


    authors: Cutter GR,Oberman A,Kouchoukos N,Rogers W

    更新日期:1982-11-01 00:00:00

  • Metabolic syndrome as a precursor of cardiovascular disease and type 2 diabetes mellitus.

    abstract:BACKGROUND:The incidence of cardiovascular disease (CVD), coronary heart disease (CHD), and type 2 diabetes mellitus (T2DM) has not been well defined in persons with the metabolic syndrome (at least 3 of the following: abdominal adiposity, low HDL cholesterol, high triglycerides, hypertension, and impaired fasting gluc...


    pub_type: 杂志文章,多中心研究


    authors: Wilson PW,D'Agostino RB,Parise H,Sullivan L,Meigs JB

    更新日期:2005-11-15 00:00:00

  • Age-dependent impairment of reendothelialization after arterial injury: role of vascular endothelial growth factor.

    abstract:BACKGROUND:The mechanisms responsible for the association between advanced age and atherosclerotic diseases are not clear. Because atherosclerosis develops in response to local endothelial injuries, we investigated the effect of aging on vascular healing and reendothelialization. METHODS AND RESULTS:Endothelium denuda...


    pub_type: 杂志文章


    authors: Gennaro G,Ménard C,Michaud SE,Rivard A

    更新日期:2003-01-21 00:00:00

  • Fibrinopeptide A and platelet factor levels in unstable angina pectoris.

    abstract::Fibrinopeptide A, platelet factor 4, beta-thromboglobulin, thromboxane B2, and 6-keto-prostaglandin F1 alpha were estimated by radioimmunoassay on venous plasma samples taken within 48 hr of admission from 16 consecutive patients with unstable angina and 15 patients with stable angina matched for clinical variables. T...


    pub_type: 杂志文章


    authors: Théroux P,Latour JG,Léger-Gauthier C,De Lara J

    更新日期:1987-01-01 00:00:00

  • Intracoronary radiation therapy improves the clinical and angiographic outcomes of diffuse in-stent restenotic lesions: results of the Washington Radiation for In-Stent Restenosis Trial for Long Lesions (Long WRIST) Studies.

    abstract:BACKGROUND:The Washington Radiation for In-Stent Restenosis Trial for long lesions (Long WRIST) was designed to determine the safety and efficacy of vascular brachytherapy for the treatment of diffuse in-stent restenosis. METHODS AND RESULTS:A total of 120 patients with diffuse in-stent restenosis in native coronary a...


    pub_type: 临床试验,杂志文章,随机对照试验


    authors: Waksman R,Cheneau E,Ajani AE,White RL,Pinnow E,Torguson R,Deible R,Satler LF,Pichard AD,Kent KM,Teirstein PS,Lindsay J,Washington Radiation for In-Stent Restenosis Trial for Long Lesions Studies.

    更新日期:2003-04-08 00:00:00

  • The nitrovasodilators. New ideas about old drugs.

    abstract::The nitrovasodilators are a diverse group of pharmacological agents that produce vascular relaxation by releasing nitric oxide. The mechanisms by which these compounds release nitric oxide vary, depending on their chemical structure. Compounds with lower oxidation states of nitrogen such as nitroprusside, nitrosamines...


    pub_type: 杂志文章,评审


    authors: Harrison DG,Bates JN

    更新日期:1993-05-01 00:00:00

  • Sustained improvement in flow-mediated vasodilation after short-term administration of dobutamine in patients with severe congestive heart failure.

    abstract:BACKGROUND:In patients with severe congestive heart failure (CHF), short-term administration of dobutamine exerts sustained clinical benefits that are partially mediated by a training-like effect on skeletal muscle. Recently, physical training has been shown to enhance endothelial function in the skeletal muscle vascul...


    pub_type: 临床试验,杂志文章


    authors: Patel MB,Kaplan IV,Patni RN,Levy D,Strom JA,Shirani J,LeJemtel TH

    更新日期:1999-01-05 00:00:00

  • Histopathology of embolic debris captured during transcatheter aortic valve replacement.

    abstract:BACKGROUND:Recent transcatheter aortic valve replacement studies have raised concerns about adverse cerebrovascular events. The etiopathology of the embolized material is currently unknown. METHODS AND RESULTS:A total of 40 patients underwent transcatheter aortic valve replacement with the use of a dual filter-based e...


    pub_type: 临床试验,杂志文章


    authors: Van Mieghem NM,Schipper ME,Ladich E,Faqiri E,van der Boon R,Randjgari A,Schultz C,Moelker A,van Geuns RJ,Otsuka F,Serruys PW,Virmani R,de Jaegere PP

    更新日期:2013-06-04 00:00:00

  • Long-term benefit of postconditioning.

    abstract:BACKGROUND:We previously demonstrated that ischemic postconditioning decreases creatine kinase release, a surrogate marker for infarct size, in patients with acute myocardial infarction. Our objective was to determine whether ischemic postconditioning could afford (1) a persistent infarct size limitation and (2) an imp...


    pub_type: 杂志文章,多中心研究,随机对照试验


    authors: Thibault H,Piot C,Staat P,Bontemps L,Sportouch C,Rioufol G,Cung TT,Bonnefoy E,Angoulvant D,Aupetit JF,Finet G,André-Fouët X,Macia JC,Raczka F,Rossi R,Itti R,Kirkorian G,Derumeaux G,Ovize M

    更新日期:2008-02-26 00:00:00

  • Only hibernating myocardium invariably shows early recovery after coronary revascularization.

    abstract:BACKGROUND:The aims of this study were to identify hibernating myocardium (hypocontractile, hypoperfused viable myocardium that regains contractility after revascularization) in the clinical setting and to predict functional outcome in patients with coronary artery disease after coronary revascularization. METHODS AND...


    pub_type: 杂志文章


    authors: Shivalkar B,Maes A,Borgers M,Ausma J,Scheys I,Nuyts J,Mortelmans L,Flameng W

    更新日期:1996-08-01 00:00:00

  • Left ventricular contractility predicts how the end-diastolic pressure-volume relation shifts during pacing-induced ischemia in dogs.

    abstract:BACKGROUND:Two types of ischemia, pacing-induced and coronary occlusion-induced, have different effects on left ventricular diastolic properties. During pacing-induced ischemia, the diastolic pressure-volume relation is said to shift upward, whereas during coronary occlusion, it is said to shift rightward or downward. ...


    pub_type: 杂志文章


    authors: Takano H,Glantz SA

    更新日期:1995-05-01 00:00:00

  • Protective effect of propylthiouracil independent of its hypothyroid effect on atherogenesis in cholesterol-fed rabbits: PTEN induction and inhibition of vascular smooth muscle cell proliferation and migration.

    abstract:BACKGROUND:Propylthiouracil (PTU) is used to treat hyperthyroid patients by its hypothyroid effect. PTU also is found to have potent antioxidant and immunosuppressive effects. These findings suggest that PTU may play a role in the prevention of atherosclerosis. METHODS AND RESULTS:This study evaluates the effect of PT...


    pub_type: 杂志文章


    authors: Chen WJ,Lin KH,Lai YJ,Yang SH,Pang JH

    更新日期:2004-09-07 00:00:00

  • Limited exercise capacity in heterozygous manganese superoxide dismutase gene-knockout mice: roles of superoxide anion and nitric oxide.

    abstract:BACKGROUND:We have reported that there is a limitation of exercise capacity in mice with defects in the expression of endothelial nitric oxide (NO) synthase, which is associated with a greater increase in whole-body oxygen consumption (VO2). We hypothesized that in states in which superoxide anion (O2-) is increased, e...


    pub_type: 杂志文章


    authors: Kinugawa S,Wang Z,Kaminski PM,Wolin MS,Edwards JG,Kaley G,Hintze TH

    更新日期:2005-03-29 00:00:00

  • Lack of association between the MEF2A gene and myocardial infarction.

    abstract:BACKGROUND:Coronary artery disease (CAD) and myocardial infarction (MI) are caused in part by genetic factors. Recently, the MEF2A gene was linked to MI/CAD in a single pedigree with autosomal-dominant pattern of inheritance. In addition, genetic variants within the gene have been associated with MI in case-control set...


    pub_type: 杂志文章


    authors: Lieb W,Mayer B,König IR,Borwitzky I,Götz A,Kain S,Hengstenberg C,Linsel-Nitschke P,Fischer M,Döring A,Wichmann HE,Meitinger T,Kreutz R,Ziegler A,Schunkert H,Erdmann J

    更新日期:2008-01-15 00:00:00

  • Thrombolytic therapy causes an increase in vascular permeability that is reversed by 1-deamino-8-D-vasopressin.

    abstract:BACKGROUND:To examine the effect of plasminogen activator therapy on vascular permeability, we used a modified rabbit mesenteric model of extravascular tissue accumulation of radiolabeled albumin. METHODS AND RESULTS:Albumin deposition was measured after saline, tissue-type plasminogen activator (t-PA; 0.86 mg/kg for ...


    pub_type: 杂志文章


    authors: Rudd MA,Johnstone MT,Rabbani LE,George D,Ware JA,Loscalzo J

    更新日期:1991-12-01 00:00:00

  • Probucol protects against adriamycin cardiomyopathy without interfering with its antitumor effect.

    abstract:BACKGROUND:The usefulness of adriamycin (ADR), a potent antitumor antibiotic, is limited by the development of life-threatening cardiomyopathy and congestive heart failure. Subcellular changes leading to heart failure are suggested to be mediated by a drug-induced increase in free radicals and lipid peroxidation. In an...


    pub_type: 杂志文章


    authors: Siveski-Iliskovic N,Hill M,Chow DA,Singal PK

    更新日期:1995-01-01 00:00:00

  • Expression of the chemokine receptor CXCR3 and its ligand IP-10 during human cardiac allograft rejection.

    abstract:BACKGROUND:Chemokines play an essential role in regulating the infiltration of leukocytes into allografts in experimental models. Little is known of their expression or function after human cardiac transplantation. METHODS AND RESULTS:We analyzed 169 sequential human endomyocardial biopsies by immunocytochemistry for ...


    pub_type: 杂志文章


    authors: Melter M,Exeni A,Reinders ME,Fang JC,McMahon G,Ganz P,Hancock WW,Briscoe DM

    更新日期:2001-11-20 00:00:00

  • Arterial stiffness and cardiovascular events: the Framingham Heart Study.

    abstract:BACKGROUND:Various measures of arterial stiffness and wave reflection have been proposed as cardiovascular risk markers. Prior studies have not assessed relations of a comprehensive panel of stiffness measures to prognosis in the community. METHODS AND RESULTS:We used proportional hazards models to analyze first-onset...


    pub_type: 杂志文章


    authors: Mitchell GF,Hwang SJ,Vasan RS,Larson MG,Pencina MJ,Hamburg NM,Vita JA,Levy D,Benjamin EJ

    更新日期:2010-02-02 00:00:00

  • Pathophysiology of Takotsubo Syndrome.

    abstract::Originally described by Japanese authors in the 1990s, Takotsubo syndrome (TTS) generally presents as an acute myocardial infarction characterized by severe left ventricular dysfunction. TTS, however, differs from an acute coronary syndrome because patients have generally a normal coronary angiogram and left ventricul...


    pub_type: 杂志文章,评审


    authors: Pelliccia F,Kaski JC,Crea F,Camici PG

    更新日期:2017-06-13 00:00:00

  • Effects of partial obstruction on phasic flow in aortocoronary grafts.

    abstract::Phasic blood flow recorded in five unobstructed dog aortocoronary bypass grafts to the left coronary artery was similar to that of normal coronary arteries, with a high diastolic-to-systolic flow ratio which averaged 2.7 +/- 0.4. With an average of 52 +/- 7% and 72 +/- 6% stenosis in the coronary artery distal to the ...


    pub_type: 杂志文章


    authors: Folts JD,Kahn DR,Bittar N,Rowe GG

    更新日期:1975-08-01 00:00:00

  • Selective augmentation of prostacyclin production by combined prostacyclin synthase and cyclooxygenase-1 gene transfer.

    abstract:BACKGROUND:We tested the hypothesis that combined cyclooxygenase-1 (COX-1) and prostacyclin synthase (PGIS) gene transfer selectively augments prostacyclin production without a concurrent overproduction of other prostanoids. METHODS AND RESULTS:ECV304 cells were transfected with bicistronic pCOX-1/PGIS versus pCOX-1 o...


    pub_type: 杂志文章


    authors: Shyue SK,Tsai MJ,Liou JY,Willerson JT,Wu KK

    更新日期:2001-04-24 00:00:00

  • Decompensation of pressure-overload hypertrophy in G alpha q-overexpressing mice.

    abstract:BACKGROUND:Receptor-mediated activation of myocardial Gq signaling is postulated as a biochemical mechanism transducing pressure-overload hypertrophy. The specific effects of Gq activation on the functional and morphological adaptations to pressure overload are not known. METHODS AND RESULTS:To determine the effects o...


    pub_type: 杂志文章


    authors: Sakata Y,Hoit BD,Liggett SB,Walsh RA,Dorn GW 2nd

    更新日期:1998-04-21 00:00:00

  • Disparities in revascularization rates after acute myocardial infarction between aboriginal and non-aboriginal people in Australia.

    abstract:BACKGROUND:This study examined revascularization rates after acute myocardial infarction (AMI) for Aboriginal and non-Aboriginal patients sequentially controlling for admitting hospital and risk factors. METHODS AND RESULTS:Hospital data from the state of New South Wales, Australia (July 2000 through December 2008) we...


    pub_type: 杂志文章


    authors: Randall DA,Jorm LR,Lujic S,O'Loughlin AJ,Eades SJ,Leyland AH

    更新日期:2013-02-19 00:00:00

  • Mutant caveolin-3 induces persistent late sodium current and is associated with long-QT syndrome.

    abstract:BACKGROUND:Congenital long-QT syndrome (LQTS) is a primary arrhythmogenic syndrome stemming from perturbed cardiac repolarization. LQTS, which affects approximately 1 in 3000 persons, is 1 of the most common causes of autopsy-negative sudden death in the young. Since the sentinel discovery of cardiac channel gene mutat...


    pub_type: 杂志文章


    authors: Vatta M,Ackerman MJ,Ye B,Makielski JC,Ughanze EE,Taylor EW,Tester DJ,Balijepalli RC,Foell JD,Li Z,Kamp TJ,Towbin JA

    更新日期:2006-11-14 00:00:00

  • Characterization of low right atrial isthmus as the slow conduction zone and pharmacological target in typical atrial flutter.

    abstract:BACKGROUND:Previous electrophysiological studies in patients with typical atrial flutter suggested that the slow conduction zone might be located in the low right atrial isthmus, which is a path formed by orifice of inferior vena cava, eustachian valve/ridge, coronary sinus ostium, and tricuspid annulus. The conduction...


    pub_type: 杂志文章


    authors: Tai CT,Chen SA,Chiang CE,Lee SH,Ueng KC,Wen ZC,Huang JL,Chen YJ,Yu WC,Feng AN,Chiou CW,Chang MS

    更新日期:1997-10-21 00:00:00

  • Increased morning incidence of myocardial infarction in the ISAM Study: absence with prior beta-adrenergic blockade. ISAM Study Group.

    abstract::The time of acute myocardial infarction was determined in all 1,741 patients of the ISAM (Intravenous Streptokinase in Acute Myocardial Infarction) Study, based on onset of clinical symptoms and evaluation of plasma CK-MB enzyme time-activity curves. The incidence of myocardial infarction was markedly increased betwee...


    pub_type: 杂志文章


    authors: Willich SN,Linderer T,Wegscheider K,Leizorovicz A,Alamercery I,Schröder R

    更新日期:1989-10-01 00:00:00