The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation
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J. Heart Lung Transplant. · Oct 2005
Left ventricular dysfunction after acute intracranial hypertension is associated with increased hydroxyl free radical production, cardiac ryanodine hyperphosphorylation, and troponin I degradation.
In addition to generating free radicals, stress-induced activation of the sympathetic nervous system results in hyperphosphorylation of the cardiac ryanodine receptor (RyR2)/calcium (Ca2+) release channel on the sarcoplasmic reticulum, causing leaky channels. These events may contribute to cytosolic Ca2+ overload and activation of Ca2+-dependent cytotoxic processes. Because myocardial dysfunction associated with intracranial hypertension is catecholamine mediated, we sought to determine in a rat model if hemodynamic changes are associated with an increase in oxidative stress, hyperphosphorylation of RyR2, and degradation of myofilament protein cardiac troponin I (TnI). ⋯ The present findings demonstrate that hemodynamic instability after intracranial hypertension is associated with oxidative stress and post-translational changes to RyR2 and TnI degradation. Despite this, the myocardial responsiveness to beta1 adrenergic stimulation is preserved in rats with depressed myocardial function.
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J. Heart Lung Transplant. · Oct 2005
Comparative StudyDifferential exercise performance on ventricular assist device support.
Ventricular assist devices (VADs) are approved for destination therapy because they improve survival in end-stage heart failure (HF). VADs are powered pneumatically or electrically. Pneumatic and electric left ventricular assist devices (LVADs) and biventricular assist devices (BiVADs) provide excellent hemodynamic support at rest, but differences in their effects on exercise tolerance are unclear. We sought to evaluate the effect of devices with varying operating parameters on exercise capacity. ⋯ HF patients supported with a pneumatic LVAD appear to have better exercise tolerance than those receiving an electric LVAD. Patients on LVAD support have better exercise tolerance than BiVAD-supported patients. This highlights the importance of right ventricular function to exercise tolerance in HF patients, and may have implications for future VAD design.
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J. Heart Lung Transplant. · Oct 2005
High prevalence of pulmonary arterial thrombi in donor lungs rejected for transplantation.
Donor hypoxemia is a common reason for the rejection of lungs for transplantation. Organ donors are at high risk for venous thromboembolism. Pulmonary arterial thrombosis could contribute to donor hypoxemia. The primary objective of this study was to prospectively quantify the incidence of pulmonary arterial thrombosis in organ donors whose lungs were rejected for transplantation. The secondary objective was to better define the spectrum of histologic abnormalities in the same group of lungs. ⋯ Pulmonary arterial thrombosis and/or pulmonary infarction are very common in organ donors whose lungs are rejected for transplantation and might contribute to lung dysfunction both in lung donors and lung recipients. Further studies are needed to define the incidence of pulmonary arterial thrombosis in organ donors whose lungs are used for transplantation and to better assess the adverse clinical consequences of donor pulmonary arterial thrombosis in lung recipients.
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J. Heart Lung Transplant. · Oct 2005
Comparative StudyLong-term outcome of bosentan treatment in idiopathic pulmonary arterial hypertension and pulmonary arterial hypertension associated with the scleroderma spectrum of diseases.
Bosentan improves clinical outcomes in pulmonary arterial hypertension (PAH), particularly in the idiopathic (IPAH) subset. Scant data are available regarding PAH associated with the scleroderma spectrum of diseases (APAH-SSD). Here we review our experience with bosentan in these 2 groups. ⋯ First-line bosentan monotherapy is associated with long-term improvement in functional class and good overall survival in patients with WHO class III IPAH. Most APAH-SSD patients experienced stability or decline in functional class and tended to have a higher mortality.
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J. Heart Lung Transplant. · Oct 2005
Potential suitability for transplantation of hearts from human non-heart-beating donors: data review from the Gift of Life Donor Program.
Organ availability limits use of heart transplantation for treatment for end-stage heart disease. Hearts are currently obtained from donors declared brain dead (heart-beating donors [HBDs]). Although use of hearts from non-heart-beating donors (NHBDs) could reduce the shortage, they are considered unusable because of possible peri-mortem ischemic injury. ⋯ Based on our assumptions, 12% to 18% of NHBDs in the study period (14 to 21 of 119 total) were potential heart donors, representing a 4% to 6% increase over of the number of heart transplants performed during the same time interval.