Orthostatic tolerance is difficult to predict in recurrent syncope patients

Schroeder, Christoph; Tank, Jens; Heusser, Karsten; Busjahn, Andreas; Diedrich, André; Luft, Friedrich C.; Jordan, Jens

doi:10.1007/s10286-010-0090-6

Cited by 7 publications

(8 citation statements)

References 35 publications

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“…Schroeder et al . [ 33 ] tested the hypothesis that detailed anthropometric and hemodynamic measurements predict orthostatic tolerance in neurally mediated syncope patients. They concluded that in those patients in the clinical laboratory, having a wide range of anthropometric and cardiovascular measurements, it is difficult to predict the orthostatic tolerance.…”

Section: Discussionmentioning

confidence: 99%

Early hemodynamic response to the tilt test in patients with syncope

Koźluk¹,

Cybulski²,

Piątkowska³

et al. 2014

aoms

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IntroductionOur aim was to evaluate the differences in the early hemodynamic response to the tilt test (HUTT) in patients with and without syncope using impedance cardiography (ICG).Material and methodsOne hundred twenty-six patients (72 female/48 male; 37 ±17 years) were divided into a group with syncope (HUTT(+), n = 45 patients) and a group without syncope (HUTT(–), n = 81 patients). ECG and ICG signals were continuously recorded during the whole examination, allowing the calculation of heart rate (HR), stroke volume (SV), and cardiac output (CO) for every beat. The hemodynamic parameters (averaged over 1 min) were analyzed at the following points of the HUTT: the last minute of resting, the period immediately after the tilt (0 min), 1 min and 5 min after the maneuver. The absolute changes of HR, SV and CO were calculated for 0, 1, and 5 min after the maneuver in relation to the values at rest (ΔHR, ΔSV, ΔCO). Also, the percentage changes were calculated (HRi, SVi, COi).ResultsThere were no differences between the groups in absolute and percentage changes of hemodynamic parameters immediately after and 1 min after tilting. Significant differences between the HUTT(+) and HUTT(–) groups were observed in the 5th min of tilting: for ΔSV (–27.2 ±21.2 ml vs. –9.7 ±27.2 ml; p = 0.03), ΔCO (–1.78 ±1.62 l/min vs. –0.34 ±2.48 l/min; p = 0.032), COi (–30 ±28% vs. –0.2 ±58%; p = 0.034).ConclusionsIn the 5th min the decrease of hemodynamic parameters (ΔSV, ΔCO, COi) was significantly more pronounced in HUTT(+) patients in comparison to the HUTT(–) group.

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Section: Discussionmentioning

confidence: 99%

Early hemodynamic response to the tilt test in patients with syncope

Koźluk¹,

Cybulski²,

Piątkowska³

et al. 2014

aoms

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show abstract

“…Beat‐to‐beat BP was continuously monitored by volume‐clamped photoplethysmography (2300 Finapres, Ohmeda, Madison, WI) on a finger that was kept at heart level throughout the experiments. Impedance cardiography (Niccomo, Medis, Ilmenau, Germany) was used to measure stroke volume continuously as previously described 29 . Special attention was paid to ensure identical positions of electrodes and pressure cuffs on all three testing days.…”

Section: Methodsmentioning

confidence: 99%

“…Impedance cardiography (Niccomo, Medis, Ilmenau, Germany) was used to measure stroke volume continuously as previously described. 29 Special attention was paid to ensure identical positions of electrodes and pressure cuffs on all three testing days.…”

Section: Subjectsmentioning

confidence: 99%

Pacemaker Current Inhibition in Experimental Human Cardiac Sympathetic Activation: A Double-Blind, Randomized, Crossover Study

Schroeder

Heusser

Zoerner

et al. 2014

Clin Pharmacol Ther

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Cardiac sympathetic activity is increased in patients with myocardial infarction, 1 unstable ischemic heart disease, 2 stress-induced cardiomyopathy, 3 and congestive heart failure. 4 Excessive cardiac sympathetic drive exacerbated by standing is the leading feature of postural tachycardia syndrome (POTS). 5 Conversely, cardiac parasympathetic regulation assessed through heart rate (HR) variability and baroreflex testing is impaired in congestive heart failure, 6,7 after myocardial infarction, 8 and in POTS. 9 Treatments addressing autonomic imbalance, including β-blockers in patients and chronic electrical vagus nerve stimulation in animals, 10 improve survival. In the sinus node, sympathetic and parasympathetic influences are integrated through hyperpolarization-activated and cyclic nucleotide-gated 4 (HCN4) channels producing "funny" or pacemaker currents (I(f)). 11 The current determines the diastolic depolarization slope of sinus node pacemaker cells, thereby setting HR. Intracellular cyclic adenosine monophosphate (cAMP) regulates HCN4 12 such that β-adrenergic stimulation augments, and cholinergic stimulation attenuates, channel conductivity. Thus, HCN4 comprises the final common pathway for autonomic HR regulation, providing a physiological basis for selective HCN4 blockade with ivabradine in the treatment of heart failure 13 and angina pectoris. 14 Yet how pharmacological HCN4 inhibition affects human autonomic cardiovascular control, particularly in the setting of increased cardiac sympathetic drive, is poorly understood. Studies in mice with inducible cardiac-specific HCN4 deletion 15 and in patients with mutations rendering HCN4 cAMP-insensitive 12 suggest that the channel may be more important for rhythm control at lower HRs. HR responses to adrenergic stimulation are surprisingly maintained. Yet selective sinus rhythm modulation leaves myocardial responses to adrenergic stimulation unopposed. Therefore, we tested the hypothesis that pharmacological HCN4 inhibition attenuates HR in a human model of severe cardiac sympathetic activation. Sympathetic activation was achieved by selective norepinephrine reuptake inhibition combined with graded orthostatic stress. RESULTSWe screened 63 men. Twenty-four subjects fulfilled all inclusion and exclusion criteria and entered the study. Nineteen men completed all three study visits and were included in the analysis Hyperpolarization-activated, cyclic nucleotide-gated 4 (HCN4) channels comprise the final pathway for autonomic heart rate (HR) regulation. We hypothesized that HCN4 inhibition could reverse autonomic imbalance in a human model of cardiac sympathetic activation. Nineteen healthy men ingested oral metoprolol+reboxetine, ivabradine+reboxetine, or placebo+reboxetine in a double-blind, randomized, crossover fashion. We assessed HR, blood pressure (BP), stroke volume, and cardiac output during rest and profound orthostatic stress. HR variability, BP variability, and baroreflex sensitivity were analyzed. Metoprolol, but not ivabradine, decreased resting HR...

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“…Quanto à influência do sexo na presença da SINC, os resultados da MPP confirmam a predominância de testes positivos no gênero feminino (93,8%); estes achados coincidem com a maioria dos estudos realizados por outros pesquisadores (LUDWIG and CONVERTINO, 1994;GANZEBOOM et al, 2006;LONGIN et al, 2008;AKCABOY et al, 2011;SCHROEDER et al, 2011;VALLEJO et al, 2015). FU et al, 2004).…”

Section: Discussionunclassified

“…Alguns autores consideram que os referidos fatores não influenciem a prevalência da SNC, enquanto outros referem que a maior estatura favoreça o aparecimento desta síndrome; como facilitadores, também têm sido relatados, a redução do peso corporal e de seu índice de massa (LUDWIG and CONVERTINO, 1994;BONDANELLI et al, 2003;DING et al, 2008;SCHROEDER et al, 2011). A constatação de que, no presente estudo, os grupos Tilt-test positivo, negativo e controle não tenham apresentado diferenças de idade altura, peso e índice de massa corporal, assume uma grande importância; isto porque, a comparação dos demais parâmetros irão abranger os três grupos que se diferem, apenas, quanto à presença ou não de síncope induzida em laboratório pelo Tilt-test.…”

Section: Discussionunclassified

Caracterização da modulação autonômica cardiovascular nas posições supina e vertical, usando-se a manobra postural passiva, em pacientes com história clínica de síncope neurocardiogênica e indivíduos saudáveis

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Orthostatic tolerance is difficult to predict in recurrent syncope patients

Abstract: In patients with neurally mediated syncope, orthostatic tolerance in the clinical laboratory is difficult to predict with a wide range of anthropometric and cardiovascular measurements and correlates poorly with syncope occurrence in real life.

Cited by 7 publications

References 35 publications

Early hemodynamic response to the tilt test in patients with syncope

Early hemodynamic response to the tilt test in patients with syncope

Pacemaker Current Inhibition in Experimental Human Cardiac Sympathetic Activation: A Double-Blind, Randomized, Crossover Study

Caracterização da modulação autonômica cardiovascular nas posições supina e vertical, usando-se a manobra postural passiva, em pacientes com história clínica de síncope neurocardiogênica e indivíduos saudáveis

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