background: in order to fit the job physiologically to the worker, understanding of acceptable work load is very important. this study was conducted to estimate energy expenditure during the work and associated factors among male workers of a steel industry. methods: in this cross-sectional study, 100 male workers employed in foolad payeh fars with dynamic job participated voluntarily. data col...

results: the average of dyssynchrony in eight cycles showed a positive correlation with dyssynchrony in target beat rr1/rr2 = 1. average of dyssynchrony in target beat was 46.77 msec, and average of 8 cycle was = 47.701, (p value = 0.776, pearson linear correlation 0.769). objectives: we proposed to evaluate intraventricular mechanical dyssynchrony by measuring time-to-peak systolic velocity be...

Introduction: Beat-to-beat variation in heart rate shows a complex dynamics, and this complexity is changed during systemic inflammatory response syndrome (e.g. sepsis). It is not known whether or not cardiac pacemaker dynamical rhythm is affected by sepsis. The aim of this study was to investigate heart rate dynamics of isolated heart as well as expression of pacemaker channels (HCN) in a r...

Background: Induction of anesthesia in patients that undergo cardiac surgery has more risk than others, because of specific cardiovascular effects of the anesthetic drugs and the preoperative state of these patients, so the hemodynamic stability is very important in these patients. It seems that midazolam have less cardiovascular side effects than thiopentone. In this study, the effects of mid...

Evidence for vagal denervation of the heart as a feature of diabetic autonomic neuropathy has been obtained by monitoring beat-to-beat variation in heart rate. Nine diabetics with autonomic neuropathy were assessed; each showed a marked reduction or absence of beat-to-beat variation in comparison with controls. Beat-to-beat variation in normal subjects is abolished by parasympathetic blockade b...

ventricular arrhythmias are one of the most important causes of annual deaths in the world, which may lead to sudden cardiac deaths. accurate and early diagnosis of ventricular arrhythmias in heart diseases is essential for preventing mortality in cardiac patients. ventricular activity on the electrocardiogram (ecg) signal is in the interval from the beginning of qrs complex to t wave end. vari...