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We thank Drs Yoneyama and Akashi for their important reference to the confounding influence of respiration on biventricular volume assessment by real-time cardiac magnetic resonance imaging. As we noted in the Discussion, changes in biventricular volumes "may be caused by physiological differences in preload attributable to the fall in intrathoracic pressures during inspiration and cardiac translation through the imaging plane."1 Real-time cardiac magnetic resonance imaging provides a novel means of expanding on the eloquent work of Natarajan et al 2 on assessing the influence of the respiratory pump on cardiac filling and function. This interaction between breathing and cardiac function has received limited attention, but now we have an excellent noninvasive tool for very accurately detailing changes in both right and left ventricular volumes with various respiratory maneuvers. We hope to provide novel data in the peer-reviewed literature soon that will detail the importance of this respiratory pump in enhancing cardiac filling. We slightly disagree with the assertion that breath-hold imaging should be considered a gold standard. Breath-holding is a nonphysiological surrogate that has previously been necessary to enable gating of cardiac magnetic resonance images. Real-time imaging enables the investigator to apply the accuracy of cardiac magnetic resonance to real physiological settings. We can neither ignore the fact that our patients breathe nor ignore the fact that most of our patients develop symptoms with exertion. This new methodology finally enables us to accurately measure cardiac function when it really matters. DisclosuresNone. References

Abstract-The monoclonal antibody 4E6 -based ELISA was used to quantify levels of oxidized LDL in plasma of 65 control subjects, 47 patients transplanted for dilated cardiomyopathy (DCM), and 60 patients transplanted for coronary artery disease (CAD). Levels of oxidized LDL were 0.68Ϯ0.039 mg/dL (meanϮSEM), 1.27Ϯ0.14 mg/dL (PϽ.001 versus control), and 1.73Ϯ0.13 mg/dL (PϽ.001 versus control and Ͻ0.01 versus DCM), respectively. Levels of oxidized LDL were significantly lower in transplanted patients with angiographically normal coronary arteries (grade 0, T he development of CAD after cardiac transplantation is a leading cause of graft failure in recipients who survive the first year after surgery. 1,2 This posttransplant arteriopathy is characterized by rapid development, 3,4 concentric narrowing of smaller coronary arteries, 5,6 and the lack of correlation with known atherogenic risk factors. [1][2][3][4][5][6] Understanding the etiology of accelerated atherosclerosis might allow identification of patients at risk for this complication.It has been suggested that ischemic injury of the heart during the peritransplant period significantly contributes to the development of accelerated atherosclerosis in heart transplant patients. 7 A correlation between LDL oxidation and atherogenesis was first suggested by experiments showing that oxidized LDL mediated injury to endothelial cells (reviewed in Reference 8) and was further supported by studies showing a protective effect of antioxidants against progression of atherosclerosis. 9 The study of the correlation between oxidized LDL and atherosclerosis has, however, been hampered by the lack of a sensitive and specific assay for oxidized LDL in plasma. In the present study we have used an ELISA that is highly specific for oxidized LDL. 10 The ELISA was used to study the association between plasma levels of oxidized LDL and CAD. Methods PatientsThe posttransplant study group contained 47 patients transplanted for DCM and 60 patients treated for CAD. The clinical characteristics of these patients are summarized in Table 1. At the time of blood sampling, between 12 and 84 months after surgery, all patients were in a stable cardiac condition without evidence of acute rejection. Adequate information about the smoking habits was available for 92 of the 107 patients (16 smokers and 76 nonsmokers). There was no adequate information about smoking habits of donors. Rejection was graded by the histopathologic classification of the International Society for Heart and Lung Transplantation. Rejections Ն grade 3A were treated. Maintenance immunosuppression consisted of triple-drug therapy including cyclosporin, azathioprine, and prednisone. Rejection episodes were treated with high-dose intravenous corticosteroids and steroid-resistant rejection with a course of OKT3, a murine anti-CD3 mAb. 11 Cytomegalovirus infection was defined as seroconversion of a seronegative recipient or a fourfold rise in titer postoperatively in a previously cytomegalovirus-positive recipient.Blood samples of 6...

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