Search results for "Rhythm"
showing 10 items of 822 documents
Iatrogenic pulmonary lesions.
2018
Treatment of patients often includes the administration of medications and sometimes radiation. While the intent is to treat an underlying condition, in some cases, adverse effects occur due to these agents. Most of these adverse effects are mild, however, some can be severe and life-threatening. Furthermore, while these effects are often reversible upon cessation of exposure, especially if the inciting agent is recognized and withdrawn early, others might be permanent or even progressing. Most common histopathologic findings in drug-induced interstitial lung disease include nonspecific interstitial pneumonia (cellular and/or fibrotic), organizing pneumonia with or without bronchiolitis, eo…
Infradian rhythms of serotonin and serotonin‐N‐acetyltransferase in the pineal gland of male rats
1983
Abstract The present investigation was carried out to determine whether in the pineal gland of male Sprague‐Dawley rats infradian rhythms with respect to serotonin, serotonin‐N‐acetyltransferase (NAT) activity, and hydroxyindole‐O‐methyltransferase (HIOMT) can be detected. The serotonin data obtained over a period of 4 weeks and subjected to power spectral analysis suggest the presence of infradian rhythms in the range of 6 and 4.3 days. NAT activity, obtained over a period of 28 days, revealed a 7‐day‐rhythm. A second peak occurring at 2.3 days remained just below the significance limit. HIOMT activity studied over a period of 8 days showed no statistically significant differences between …
Self-reported reasons for on-duty sleepiness among commercial airline pilots
2021
Experimental and epidemiological research has shown that human sleepiness is determined especially by the circadian and homeostatic processes. The present field study examined which work-related factors airline pilots perceive as causing on-duty sleepiness during short-haul and long-haul flights. In addition, the association between the perceived reasons for sleepiness and actual sleepiness levels was examined, as well as the association between reporting inadequate sleep causing sleepiness and actual sleep-wake history. The study sample consisted of 29 long-haul (LH) pilots, 28 short-haul (SH) pilots, and 29 mixed fleet pilots (flying both SH and LH flights), each of whom participated in a…
Kinematics of shoulder abduction in the scapular plane
1995
In this paper the kinematics of arm abduction in the scapular plane of 38 healthy experimental subjects is reported. The ratio of the glenohumoral and the scapulothoracic components of the motion were determined and the influence of the abduction speed and of the external load on it were investigated. The investigation of the effect of abduction speed involved all 38 subjects. Each of them performed one slow and one fast abduction. Statistical analysis showed that there were large differences between individuals, but that for any one individual the abduction process is essentially reproducible. For the one individual there is a strong, linear relationship between glenohumeral and scapulotho…
A 35-year effective treatment of catecholaminergic polymorphic ventricular tachycardia with propafenone
2018
Key Teaching Points • Despite proven catecholaminergic polymorphic ventricular tachycardia (CPVT) with pathogen RyR2 mutation and recurrent syncope, patients could have a favorable long-term outcome over 35 years under treatment. • Propafenone could be effective for treatment of patients with CPVT. • The beneficial effect of the monotherapy with propafenone in our patient may result from the combined antiarrhythmic effect of this drug with Na+ channel blockade and beta blocker capabilities.
The controversial relationship between exercise and atrial fibrillation: clinical studies and pathophysiological mechanisms
2015
Atrial fibrillation is the most common clinically significant arrhythmia observed both in the general population and in competitive athletes. The most important risk factors are all preventable by regular physical activity. However, although the benefits of moderate physical activity in controlling cardiovascular risk factors and decreasing the risk of atrial fibrillation have been extensively proved, concerns have arisen about the potential negative effects of vigorous exercise, particularly in endurance athletes. Furthermore, in a subset of patients with atrial fibrillation younger than 60 years, routine evaluation does not reveal any cardiovascular disease or any other known causal facto…
Evaluation of atrial function by 2D strain echocardiography in patients with atrial fibrillation
2012
Abstract Objectives To evaluate atrial function by 2D strain in patients with atrial fibrillation (AF) and normal or slightly increased atrial size and to verify whether lower atrial strain is associated with more frequent AF recurrences. Materials and methods We studied 50 patients with AF, mean age 59.6 ± 13 years and 50 age-and gender-matched controls. We analyzed left atrial function through 2Dstrain imaging, after the re-establishment of sinus rhythm (SR) and we investigated about the recurrences of the arrhythmia. Results Atrial strain (AS) was lower in AF patients vs controls (LA p Conclusions The assessment of atrial function by strain imaging might help to identify patients who nee…
Zirkadiane Blutdruckrhythmik bei der Präeklampsie: Ein Prädiktor für die maternale und geburtshilfliche Situation?
2003
Background Preeclampsia is a pregnancy-induced multiorganic disease. The incidence is 5 - 7 % in all pregnant women. To assess the value of circadian blood pressure rhythm in preeclamptic women, 24-hour blood pressure monitoring might be useful. The purpose of this study was to determine the predictive value of circadian blood pressure rhythm for the maternal and obstetrical outcome in patients with mild preeclampsia. Patients and methods Sixty-six patients with mild preeclampsia underwent 24-hour blood pressure monitoring between 29 and 39 weeks gestation. Twenty-eight patients with normal circadian blood pressure rhythm were compared with thirty-eight patients with suspended circadian blo…
A hybrid stimulation strategy for suppression of spiral waves in cardiac tissue
2011
International audience; Atrial fibrillation (AF) is the most common cardiac arrhythmia whose mechanisms are thought to be mainly due to the self perpetuation of spiral waves (SW). To date, available treatment strategies (antiarrhythmic drugs, radiofrequency ablation of the substrate, electrical cardioversion) to restore and to maintain a normal sinus rhythm have limitations and are associated with AF recurrences. The aim of this study was to assess a way of suppressing SW by applying multifocal electrical stimulations in a simulated cardiac tissue using a 2D FitzHugh-Nagumo model specially convenient for AF investigations. We identified stimulation parameters for successful termination of S…
Personalized Cardiac Computational Models: From Clinical Data to Simulation of Infarct-Related Ventricular Tachycardia.
2019
In the chronic stage of myocardial infarction, a significant number of patients develop life-threatening ventricular tachycardias (VT) due to the arrhythmogenic nature of the remodeled myocardium. Radiofrequency ablation (RFA) is a common procedure to isolate reentry pathways across the infarct scar that are responsible for VT. Unfortunately, this strategy show relatively low success rates; up to 50% of patients experience recurrent VT after the procedure. In the last decade, intensive research in the field of computational cardiac electrophysiology (EP) has demonstrated the ability of three-dimensional (3D) cardiac computational models to perform in-silico EP studies. However, the personal…