Cardiology
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Fluid overload is common before, during and after cardiac surgery. The fluid associated with cardiopulmonary bypass (CPB) and cardioplegia is a particularly important source of such fluid overload. In addition, renal dysfunction, which is common in these patients, participates in the pathogenesis of a positive sodium and water balance. ⋯ However, in many patients, diuretics do not achieve sufficient sodium and water diuresis. In these patients, the application of hemofiltration (HF) during CPB and also immediately after CPB is an effective and safe approach to the maintenance of fluid homeostasis. If acute renal failure occurs, early intervention with HF may even improve survival.
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Comparative Study
Autonomic patterns preceding and following accelerated idioventricular rhythm in acute myocardial infarction.
We have investigated the potential relationship between cardiac autonomic activity and accelerated idioventricular rhythm (AIVR) in response to reperfusion in the setting of an acute myocardial infarction (AMI) through spectral analysis of heart rate variability (HRV). ⋯ Our results indicate that reperfusion-induced AIVR is modulated by sympathetic stimulatory effects, whereas a counterregulatory vagal response seems to exert a profound effect upon its suppression. Clinically, the occurrence of early sustained AIVR appears to offer reliable information about both timely reperfusion and sustained and effective coronary artery patency.
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Fluid overload may occur in patients with congestive heart failure, especially when there is associated acute renal failure. When the pharmacological approach is not sufficient to maintain the patient's fluid balance, extracorporeal therapies must be instituted. However, since the ultrafiltration rate may be faster than fluid refilling from the interstitial space, remarkable changes in the circulating blood volume may occur. ⋯ The variations in blood pressure were paralleled by variations in blood volume, which were greater with UF than with SCUF. In conclusion, extracorporeal ultrafiltration can be used to control the fluid balance in congestive heart failure, but it is advisable to prescribe low ultrafiltration rates over an extended period of time. The use of on-line blood volume monitors can be of further help in improving tolerance and the hemodynamic response.