Characterization of impaired ventricular repolarization by quantification of QT delay after heart rate changes in stress test

2021 ◽  
Vol 69 ◽  
pp. 88
Author(s):  
Cristina Parez ◽  
Esther Pueyo ◽  
Juan Pablo Marti-nez ◽  
Pablo Laguna
Keyword(s):  
Heart Rate ◽  
Stress Test ◽  
Ventricular Repolarization

Characterization of CMOS Structures (0.6 µm process) Submitted to HBM and COM ESD Stress Tests

1997 ◽  
Author(s):  
G. Meneghesso ◽  
E. Zanoni ◽  
P. Colombo ◽  
M. Brambilla ◽  
R. Annunziata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrostatic Discharge ◽  
Stress Test ◽  
Complete Characterization ◽  
Stress Tests ◽  
Test Procedures ◽  
Emission Microscopy ◽  
Fast Rise ◽  
Scanning Electron

Abstract In this work, we present new results concerning electrostatic discharge (ESD) robustness of 0.6 μm CMOS structures. Devices have been tested according to both HBM and socketed CDM (sCDM) ESD test procedures. Test structures have been submitted to a complete characterization consisting in: 1) measurement of the tum-on time of the protection structures submitted to pulses with very fast rise times; 2) ESD stress test with the HBM and sCDM models; 3) failure analysis based on emission microscopy (EMMI) and Scanning Electron Microscopy (SEM).

scholarly journals Influence of a Suggestive Placebo Intervention on Psychobiological Responses to Social Stress

2015 ◽  
Vol 21 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Frank Zimmermann-Viehoff ◽  
Nico Steckhan ◽  
Karin Meissner ◽  
Hans-Christian Deter ◽  
Clemens Kirschbaum
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Salivary Cortisol ◽  
Psychosocial Stress ◽  
Social Stress ◽  
Stress Test ◽  
Alpha Amylase ◽  
Subjective Stress ◽  
Psychological Variables ◽  
Placebo Intervention

We tested the hypothesis that a suggestive placebo intervention can reduce the subjective and neurobiological stress response to psychosocial stress. Fifty-four healthy male subjects with elevated levels of trait anxiety were randomly assigned in a 4:4:1 fashion to receive either no treatment (n = 24), a placebo pill (n = 24), or a herbal drug (n = 6) before undergoing a stress test. We repeatedly measured psychological variables as well as salivary cortisol, alpha-amylase, and heart rate variability prior to and following the stress test. The stressor increased subjective stress and anxiety, salivary cortisol, and alpha-amylase, and decreased heart rate variability (all P < .001). However, no significant differences between subjects receiving placebo or no treatment were found. Subjects receiving placebo showed increased wakefulness during the stress test compared with no-treatment controls ( P < .001). Thus, the suggestive placebo intervention increased alertness, but modulated neither subjective stress and anxiety nor the physiological response to psychosocial stress.

Mechanisms Underlying QT Interval Adaptation Behind Heart Rate During Stress Test

2021 ◽  
Author(s):  
Ruben Cebollada ◽  
Cristina Perez ◽  
Konstantinos A Mountris ◽  
Juan Pablo Martinez ◽  
Pablo Laguna ◽  
...  
Keyword(s):  
Heart Rate ◽  
Qt Interval ◽  
Stress Test

Impaired heart rate recovery may predict radial artery spasm in patients undergoing coronary angiography via radial access

2021 ◽  
Author(s):  
İsmail Gürbak ◽  
Arda Güler ◽  
Cafer Panç ◽  
Ahmet Güner ◽  
Mehmet Ertürk
Keyword(s):  
Heart Rate ◽  
Coronary Angiography ◽  
Radial Artery ◽  
Autonomic Dysfunction ◽  
Heart Rate Recovery ◽  
Stress Test ◽  
Female Gender ◽  
Current Data ◽  
Autonomic Nervous System Dysfunction ◽  
Procedural Time

Objectives: Radial artery spasm (RAS) is associated with several pathophysiological pathways, including endothelial and autonomic dysfunction, and causes failed coronary interventions. Heart rate recovery (HRR) is a simple measurement of autonomic nervous system dysfunction. We aimed to investigate the relationship between HRR and RAS during coronary angiography (CA) in the present study. Patients and Methods: This study included 167 patients (mean age 54.6 ± 8.2, 131 males) who underwent a treadmill stress test (TST) according to the Bruce protocol before trans-radial CA. HRR in the first minute (HRR1) was calculated as the difference between peak heart rate and heart rate one minute after the TST. Patients were divided into two groups according to the presence of RAS. Results: Among the study population, RAS developed in 26 patients (15.5%). HRR1 and HRR in the third minute (HRR3) were lower in the RAS group. Also, the abnormal HRR1 rate was higher in the RAS group (35.5% vs. 76.9%, p < 0.001). Total procedural time, more than one puncture attempt, more than one catheter use, fluoroscopy time, radiation exposure, contrast volume was higher in the RAS group. Female gender, total procedural time, more than one catheter use, and abnormal HRR1 were independent predictors of RAS. Conclusion: The current data suggest that a significant relationship was found between abnormal HRR1 and RAS. HRR, a simple autonomic dysfunction parameter, can provide additional information regarding the success of radial procedures.

scholarly journals Fractal fluctuations in the cardiovascular dynamical system : from the autonomic control to the central nervous system influence

2021 ◽  
Author(s):  
Asif Hasan Sharif
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Dynamic Feature ◽  
Scale Free ◽  
Autonomic Nervous ◽  
Factorization Technique ◽  
The Central Nervous System

The fractal component in the complex fluctuations of the human heart rate represents a dynamic feature that is widely observed in diverse fields of natural and artificial systems. It is also of clinical significance as the diminishing of the fractal dynamics appears to correlate with heart disease processes and adverse cardiac events in old age. While the autonomic nervous system directly controls the pacemaker cells of the heart, it does not provide an immediate characterization of the complex heart rate variability (HRV). The central nervous system (CNS) is known to be an important modulator for various cardiac functions. However, its role in the fractal HRV is largely unclear. In this research, human experiments were conducted to study the influence of the central nervous system on fractal dynamics of healthy human HRV. The head up tilt (HUT) maneuver is used to provide a perturbation to the autonomic nervous system. The subsequent fractal effect in the simultaneously recorded electroencephalography and beat-to-beat heart rate data was examined. Using the recently developed multifractal factorization technique, the common multifractality in the data fluctuation was analyzed. An empirical relationship was uncovered which shows the increase (decrease) in HRV multifractality is associated with the increase (decrease) in multifractal correlation between scale-free HRV and the cortical expression of the brain dynamics in 8 out of 11 healthy subjects. This observation is further supported using surrogate analysis. The present findings imply that there is an integrated central-autonomic component underlying the cortical expression of the HRV fractal dynamics. It is proposed that the central element should be incorporated in the fractal HRV analysis to gain a more comprehensive and better characterization of the scale-free HRV dynamics. This study provides the first contribution to the HRV multifractal dynamics analysis in HUT. The multivariate fractal analysis using factorization technique is also new and can be applied in the more general context in complex dynamics research.

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