Revista brasileira de cirurgia cardiovascular : órgão oficial da Sociedade Brasileira de Cirurgia Cardiovascular
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Rev Bras Cir Cardiovasc · Apr 2009
ReviewBasic notions of heart rate variability and its clinical applicability.
Autonomic nervous system (ANS) plays an important role in the regulation of the physiological processes of the human organism during normal and pathological conditions. Among the techniques used in its evaluation, the heart rate variability (HRV) has arising as a simple and non-invasive measure of the autonomic impulses, representing one of the most promising quantitative markers of the autonomic balance. The HRV describes the oscillations in the interval between consecutive heart beats (RR interval), as well as the oscillations between consecutive instantaneous heart rates. ⋯ Changes in the HRV patterns provide a sensible and advanced indicator of health involvements. Higher HRV is a signal of good adaptation and characterizes a health person with efficient autonomic mechanisms, while lower HRV is frequently an indicator of abnormal and insufficient adaptation of the autonomic nervous system, provoking poor patient's physiological function. Because of its importance as a marker that reflects the ANS activity on the sinus node and as a clinical instrument to assess and identify health involvements, this study reviews conceptual aspects of the HRV, measurement devices, filtering methods, indexes used in the HRV analyses, limitations in the use and clinical applications of the HRV.
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Patients with bullets in the pericardial sac without myocardial injuries are rare, and most commonly are associated with significant trauma. The diagnosis of an intrapericardial foreign body can be difficult. Its removal is always indicated because it prevents pericarditis, either sterile or infectious, with potential for other significant complications. The authors present two cases of a meandering bullet in the pericardial sac and propose approach and perform review of the literature.
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Rev Bras Cir Cardiovasc · Jan 2009
Effects of ischemic postconditioning on left ventricular function of isolated rat hearts.
To assess the effects of ischemic postconditioning on left ventricular function in isolated rat hearts. ⋯ The ischemic postconditioning by three cycles of reperfusion/ischemia of 10/10s demonstrated to be effective for preservation of the myocardial contractility in isolated rat hearts which had undergone 20 min of ischemia.