Cardiology
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Currently, several modalities are available to predict viability, however, studies comparing various modalities validated by functional recovery after revascularization are scarce. This study analyzed the relative merits of low-dose dobutamine echocardiography, F-18 deoxyglucose (FDG) positron emission tomography (PET) and (99m)Tc sestamibi single-photon emission computed tomography to predict functional recovery after revascularization in patients with chronic myocardial infarction. ⋯ Recovery of chronically dysfunctional myocardium can be predicted with high accuracy by stimulation of contractile reserve or by concordant match of preserved glucose metabolism and residual perfusion.
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It is unknown whether surgical revascularization of viable and chronic reversibly dysfunctional myocardium in patients with heart failure is associated with a favorable effect on the autonomic control of heart rate. We studied 38 coronary artery bypass surgery (CABG) patients with an ejection fraction of 36 +/- 7%. ⋯ In spite of viable myocardium and recovery of left ventricular function following CABG, HRV indices were reduced 6 months postoperatively. A potential prognostic benefit gained by revascularizing patients with viability may occur in spite of deteriorated autonomic control of heart rate.
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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.
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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.