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Impedance cardiography

Jesús Escrivá Muñoz, Y Pan, S Ge, E W Jensen, M Vallverdú
The purpose of this document is to describe a methodology to select the most adequate time-frequency distribution (TFD) kernel for the characterization of impedance cardiography signals (ICG). The predominant ICG beat was extracted from a patient and was synthetized using time-frequency variant Fourier approximations. These synthetized signals were used to optimize several TFD kernels according to a performance maximization. The optimized kernels were tested for noise resistance on a clinical database. The resulting optimized TFD kernels are presented with their performance calculated using newly proposed methods...
March 16, 2018: Medical & Biological Engineering & Computing
Devin B Phillips, Craig D Steinback, Sophie É Collins, Desi P Fuhr, Tracey L Bryan, Eric Y L Wong, Vincent Tedjasaputra, Mohit Bhutani, Michael K Stickland
COPD patients have increased central arterial stiffness and muscle sympathetic nervous activity (MSNA), both of which contribute to cardiovascular (CV) dysfunction and increased CV risk. Previous work suggests that COPD patients have elevated carotid chemoreceptor (CC) activity/sensitivity, which may contribute to the elevated MSNA and arterial stiffness. Accordingly, the effect of CC inhibition on central arterial stiffness, MSNA and CV function at rest in COPD patients was examined in a randomized placebo-controlled study...
March 12, 2018: Journal of Physiology
Eugenia Gkaliagkousi, Panagiota Anyfanti, Sophia Chatzimichailidou, Areti Triantafyllou, Antonios Lazaridis, Spyros Aslanidis, Stella Douma
Predictors of adverse cardiovascular outcomes include elevated nighttime systolic blood pressure (SBP) and a non-dipping pattern. We investigated whether these factors correlate with systemic inflammation, cardiovascular risk, and markers of central and peripheral vascular damage in rheumatoid arthritis (RA), a disease characterized by excess cardiovascular risk. Twenty-four-hour ambulatory blood pressure monitoring was applied in patients and controls. Vascular assessments included measurement of arterial stiffness (pulse wave velocity) and carotid atherosclerosis (carotid intima-media thickness)...
March 9, 2018: Journal of Human Hypertension
Ineke Nederend, Eco J C de Geus, Lucia J M Kroft, Jos J M Westenberg, Nico A Blom, Arend D J Ten Harkel
BACKGROUND: Coarctation of the aorta (CoA) is one of the most common congenital heart defects. Due to improved surgical techniques, most patients live into adulthood. However, late complications including hypertension, recoarctation and arrhythmias are common. The autonomic nervous system (ANS) might play a role in the pathology. The aim of this study was to evaluate cardiac ANS activity and cardiac function in children after CoA repair and investigate the relationship between the two...
March 5, 2018: Annals of Thoracic Surgery
Mohamad Forouzanfar, Fiona C Baker, Massimiliano de Zambotti, Corey McCall, Laurent Giovangrandi, Gregory T A Kovacs
Impedance cardiography is the most common clinically validated, noninvasive method for determining the timing of the opening of the aortic valve, an important event used for measuring preejection period, which reflects sympathetic beta-adrenergic influences on the heart. Automatic detection of the exact time of the opening of the aortic valve (B point on the impedance cardiogram) has proven to be challenging as its appearance varies between and within individuals and may manifest as a reversal, inflection, or rapid slope change of the thoracic impedance derivative's (dZ/dt) rapid rise...
March 7, 2018: Psychophysiology
Gavin P Trotman, Sarah E Williams, Mary L Quinton, Jet J C S Veldhuijzen van Zanten
BACKGROUND: The theory of challenge and threat states in athletes (TCTSA) proposes psychological antecedents will predict psychological and cardiovascular responses to stress. The present study investigated this theory in two contextually different stress tasks. METHOD: 78 males completed a computerised competition and a public speaking task. Cardiovascular activity was measured with impedance cardiography and a blood pressure monitor. Challenge and threat antecedents, indicators of challenge and threat and emotions were assessed pre- and post-tasks...
February 22, 2018: International Journal of Psychophysiology
Antti J Tikkakoski, Pauliina Kangas, Lauri Suojanen, Anna M Tahvanainen, Arttu Eräranta, Mika A P Kähönen, Kalle Sipilä, Jukka T Mustonen, Ilkka H Pörsti
The change in augmentation index following salbutamol inhalation has been applied to evaluate endothelial function. We examined the contribution of salbutamol-induced increase in heart rate to the observed decrease in augmentation index. Haemodynamics were recorded using whole body impedance cardiography and continuous pulse-wave analysis from tonometric radial blood pressure. All subjects (n=335, mean age 46, body mass index 26, 48% men) were without medications with cardiovascular influences. The effects of salbutamol inhalation (0...
February 24, 2018: Basic & Clinical Pharmacology & Toxicology
Jesús Escrivá Muñoz, Pedro Gambús, Erik W Jensen, Montserrat Vallverdú
OBJECTIVE: This works investigates the time-frequency content of impedance cardiography signals during a propofol-remifentanil anesthesia. MATERIALS AND METHODS: In the last years, impedance cardiography (ICG) is a technique which has gained much attention. However, ICG signals need further investigation. Time-Frequency Distributions (TFDs) with 5 different kernels are used in order to analyze impedance cardiography signals (ICG) before the start of the anesthesia and after the loss of consciousness...
January 2018: Methods of Information in Medicine
Arthur P DeMarzo
New guidelines on hypertension eliminated the classification of prehypertension and divided those blood pressure (BP) levels into elevated BP and stage 1 hypertension. For elevated BP, this study showed that cardiovascular (CV) abnormalities were prevalent in adults over 40 years of age with at least 2 CV risk factors. Detecting abnormalities of the CV system moves a patient from being at high risk to having earlystage cardiovascular disease (CVD) and supports a decision to treat. By redefining stage 1 and lowering the target BP, the new guidelines have set an ambitious goal for early intervention to prevent progression of CVD...
February 22, 2018: High Blood Pressure & Cardiovascular Prevention: the Official Journal of the Italian Society of Hypertension
Iris M Spruit, Tom F Wilderjans, Henk van Steenbergen
Posterror slowing (PES) is the observation that people respond slower on trials subsequent to error commissions than on trials subsequent to correct responses. Different accounts have been proposed to explain PES. On the one hand, it has been suggested that PES arises from an adaptive increase in cognitive control following error commission, thereby making people more cautious after making an error. On the other hand, PES has been attributed to an orienting response, indicating that attention is shifted toward the error...
February 20, 2018: Cognitive, Affective & Behavioral Neuroscience
Marion Dupuis, Elise Noel-Savina, Gregoire Prévot, Laurent Tétu, Fabien Pillard, Daniel Rivière, Alain Didier
BACKGROUND: Cardiac output (CO) is a prognostic factor in pulmonary hypertension (PH). Right heart catheterisation using the direct Fick method or thermodilution (TD) is the reference technique for CO measurement. Impedance cardiography (IPc) is a known non-invasive method of measuring CO. OBJECTIVES: In our study, we assume that the measurement of CO by IPc using the PHYSIOFLOW® system is as accurate as TD or using the direct Fick method in patients with PH in group 1 or group 4...
February 9, 2018: Respiration; International Review of Thoracic Diseases
R Nazário Leão, P Marques da Silva, R Marques Pocinho, M Alves, D Virella, R Palma Dos Reis
INTRODUCTION: The progression of hypertensive heart disease leads to the left ventricular diastolic dysfunction (LVDD), which is associated with increased cardiovascular morbidity and mortality. The purpose of this analysis is to explore the determinants for LVDD in patients with hypertension. METHODS: This is a secondary analysis of data of Impedance Cardiography in the Evaluation of Left Ventricular Diastolic Dysfunction in Patients with Arterial Hypertension (IMPEDDANS) Study...
February 2, 2018: Hipertensión y Riesgo Vascular
Jeffrey L Kibler
Beyond the construct of cardiovascular reactivity, the measurement of cardiovascular recovery from stress represents an important index of exaggerated physiological arousal and disease risk. Cardiovascular recovery in posttraumatic stress disorder (PTSD) has not received adequate attention. The present study examined whether cardiovascular recovery following an oral speaking stressor was associated with the severity of PTSD symptoms, and whether cognitive stress appraisals of threat and challenge were significantly associated with PTSD severity and recovery...
February 1, 2018: Journal of Traumatic Stress
Tao Wang, Yan Zhang, Qingxia Li, Shumin Jia, Changjin Shi, Kai Niu, Bing Liu
Acute kidney injury (AKI) in cancer patients may disrupt anticarcinogenic treatment and greatly increase associated mortality rates. The present study reported on the management of cancer patients with AKI and, from the nephrologic viewpoint, on the significance of fine volume control during the continuous renal replacement therapy (CRRT). The records of 117 cancer patients with AKI treated over three years were reviewed and their data were compared with those of 120 healthy controls. AKI was defined according to the Kidney Disease: Improving Global Outcomes criteria with serum creatinine levels determined on initial admission and for the diagnosis of AKI...
December 2017: Experimental and Therapeutic Medicine
Jacob Volmer Stidsen, Jens Steen Nielsen, Jan Erik Henriksen, Søren Gunnar Friborg, Reimar Wernich Thomsen, Thomas Bastholm Olesen, Michael Hecht Olsen, Henning Beck-Nielsen
INTRODUCTION: We present the protocol for a multifactorial intervention study designed to test whether individualised treatment, based on pathophysiological phenotyping and individualised treatment goals, improves type 2 diabetes (T2D) outcomes. METHODS AND ANALYSIS: We will conduct a prospective controlled multicentre open-label intervention study, drawing on the longitudinal cohort of the Danish Centre for Strategic Research in Type 2 Diabetes (DD2). New clinically diagnosed patients with T2D in the intervention group will be assigned to receive individualised treatment by their general practitioner...
December 10, 2017: BMJ Open
G Waisman
Hypertension is a haemodynamic disorder resulting from a persistent mismatch between cardiac output and peripheral resistance. Hypertension undergoes haemodynamic progression during its natural history. Impedance cardiography is a method of evaluating the cardiovascular system that obtains haemodynamic information from beat to beat through the analysis of variations in the impedance of the thorax on the passage of an electric current. Impedance cardiography unmasks the haemodynamic deterioration underlying the increase in blood pressure as age and systolic blood pressure increases...
January 2018: Hipertensión y Riesgo Vascular
C H Turkseven, E Pekoglu, B Buyukakilli
BACKGROUND AND OBJECTIVES: This study was aimed to examine how inotropic effects of intravenously injected epinephrine change thoracic impedance measurements and to reveal the possible effects of this change on other hemodynamic parameters by using the technique of impedance cardiography. METHODS: 10 male Wistar Albino rats were divided into two equal groups: control and epinephrine. 0.2 mg/kg of epinephrine was administered to the rats in the epinephrine group via the tail vein...
2017: Bratislavské Lekárske Listy
E Kale Edmiston, Rachael A Muscatello, Blythe A Corbett
Introduction: The autonomic nervous system (ANS) is involved in regulating social behavior; Autism Spectrum Disorder (ASD) is characterized by alterations in social behavior and reduced physiological response to threat. We hypothesized that adolescents with ASD would show reduced ANS response to social threat. Methods: Eighteen males with ASD and thirteen males with typical development (TD), ages 12 to 17, completed a social threat paradigm while wearing an impedance cardiography apparatus...
April 2017: Research in Autism Spectrum Disorders
Rodrigo Nazário Leão, Pedro Marques Da Silva, Rita Marques Pocinho, Marta Alves, Daniel Virella, Roberto Palma Reis
BACKGROUND: Impedance cardiography (ICG) is a noninvasive hemodynamic monitoring tool which can define hypertensive patients' hemodynamic profiles and help to tailor antihypertensive therapy. This study assesses the concordance between ICG-derived indexes used to evaluate left ventricular performance and transthoracic echocardiography (TTE) in hypertensive patients. METHODS: In this IMPEDDANS post-hoc analysis, the ICG-derived indexes are compared with TTE by Bland-Altman method...
November 27, 2017: Clinical and Experimental Hypertension: CHE
Bozena Urbanek, Krzysztof Kaczmarek, Artur Klimczak, Jan Ruta, Michal Chudzik, Katarzyna Piestrzeniewicz, Pawel Ptaszynski, Jerzy Krzysztof Wranicz
BACKGROUND & OBJECTIVES: The clinical benefit of optimization (OPT) of atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) remains debatable. This study was aimed to determine the influence of AVD and VVD OPT on selected parameters in patients early after CRT implantation and at mid-term follow up (FU). METHODS: Fifty two patients (61±10 yr, 23 males) with left bundle branch block, left ventricular ejection fraction (LVEF) ≤35 per cent and heart failure were selected for CRT implantation...
July 2017: Indian Journal of Medical Research
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