Effect of position on the residual heart rate variability in patients after orthotopic heart transplantation.

BACKGROUND: This study investigated the effects of position on heart rate variability (HRV) in patients some years after orthotopic heart transplantation (OHT) surgery. METHODS: Spectral HRV analysis was performed on 15 patients after OHT and 16 patients with coronary artery disease (CAD). HRV measures were compared between OHT and CAD patients in four randomly ordered positions [supine, right lateral decubitus (RLD), left lateral decubitus (LLD), and upright]. Multivariable linear regression analysis was used to identify the factors associated with cardiac function and HRV of OHT patients in supine position, and the factors associated with the outcome (OHT or CAD) of the patients. RESULTS: The powers in all frequency ranges were significantly decreased in all four positions in OHT patients about 9 years after OHT surgery, as compared with those of CAD patients. Both RLD and LLD positions can lead to a significantly higher normalized high-frequency power in OHT patients than the supine position, as compared with the CAD patients. The LLD position seemed to be better than the other recumbent positions in terms of vagal enhancement in the OHT patients. Multivariable linear regression analysis showed that the left ventricular ejection fraction of OHT patients can be predicted from a linear combination of the OHT to HRV interval, and normalized very low-frequency power in the supine position. Furthermore, better cardiac function and the presence of cardiomyopathy would increase the necessity of OHT surgery, while the use of nitrates would decrease the necessity of OHT surgery. CONCLUSION: Both the RLD and LLD positions, especially the LLD position, can lead to a higher vagal modulation in OHT patients about 9 years after OHT surgery, provided that the HRV measures can still be regarded as indicators of autonomic nervous modulation in such patients. Moreover, left ventricular ejection fraction, cardiomyopathy, and the use of nitrates were all associated with the necessity of OHT surgery.

Concomitant Bentall operation plus aortic arch replacement surgery.

BACKGROUND: The Bentall operation is recommended for thoracic aortic dissection or aneurysm involving the aortic root. However, if the lesion extends to the aortic arch, concomitant Bentall operation plus aortic arch replacement (CoBAAR) surgery is required. CoBAAR is challenging because of its complex cardiopulmonary procedure, prolonged cardiopulmonary bypass time, and demanding operative techniques. Therefore, surgical mortality and morbidity rates for CoBAAR are very high. However, the Bentall operation performed as a single procedure may lead to reoperation if the residual aneurysm progresses. Therefore, CoBAAR as a one-stage surgery can lower the need for reoperation and possible further complications. METHODS: Nine patients received CoBAAR during January 2005 to May 2010. Six patients were diagnosed with Sanford type A aortic dissection and three with nondissecting ascending aortic and arch aneurysm. Four patients received a Bentall operation plus hemiarch replacement. The others received a Bentall operation plus total arch replacement along with elephant trunk because of extensive lesions. RESULTS: The in-hospital mortality was 11.1% (1 patient with total arch replacement). Morbidity included stroke (2 patients), spinal cord injury (1 patient), mechanical ventilation for more than 72 hours (5 patients), and temporary renal dialysis (3 patients). Eight patients survived. CONCLUSION: CoBAAR is a demanding operative technique requiring complex cardiopulmonary bypass. However, surgeons can perform this procedure on extensive ascending aortic dissection or aneurysm patients, achieving satisfactory results.

Thrombelastography change after bridging to left ventricular assist device from extracorporeal membrane oxygenation patients.

BACKGROUND: Circulatory assist devices are applied to support patients with end-stage heart failure or circulatory collapse. Extracorporeal membrane oxygenation (ECMO) and ventricular assist device (VAD) are the two devices that are commonly used in these situations. However, in patients undergoing ECMO, complications occur more frequently and are more severe than in those with VAD, especially in patients with coagulopathy. The cause of coagulopathy is seldom reported; therefore, the current prospective study was designed to compare the coagulation status between patients who received ECMO and bridged VAD thereafter. METHODS: The cases for our study were collected between December 2005 and January 2010. A total of 21 patients with VAD were enrolled. Seven patients received initial ECMO support and were subsequently shifted to VAD. Use of blood transfusion products by patients was recorded during application of ECMO and VAD. Thrombelastography (TEG) was performed pre-ECMO and pre-VAD, and thereafter to 1 week post-VAD implantation. The relevant parameters that were examined included coagulation time (R: resting, K: kinetics, seconds), angle (α, degrees), maximal amplitude (MA, mm), clot strength (G, dynes/cm(2)), and estimated percent lysis in 30 minutes (LY30, %). Coagulation status and average unit per day of blood transfusion at pre-VAD and post-VAD status were recorded. TEGs of pre-VAD and post-VAD implantation were compared in order to determine the frequency of bleeding. RESULTS: Average results from seven cases were incorporated into the current analysis. The patient transfusion requirement was reduced after implantation of the VAD. The TEG of post-VAD implantation was improved from the earlier pre-VAD results (ECMO status). Ultimately, TEG resulted in significant differences in R, K, angle, MA, and G, postoperatively. CONCLUSION: Coagulopathy of patients with VAD improved after bridging from ECMO, which can be attributed to improved coagulation factor and platelet function. Thus, bleeding complications are reduced.

Malignancy after heart transplantation.

BACKGROUND: The purpose of this study was to assess the incidence and type of malignancies after heart transplantation at a medical institute in Taiwan. METHODS: From January 1987 to December 2008, a total of 66 patients who survived more than 30 days after transplantation were enrolled in this study. RESULTS: Of the 66 heart transplant recipients, 8 (12.1%) post-transplant malignancies were diagnosed: 5 posttransplant lymphoproliferative diseases (PTLD), 1 prostate cancer, 1 lung cancer, and 1 squamous cell carcinoma of the cheek. The clinical presentations were diverse, and the diagnoses were confirmed by biopsy. Only 1 patient died of PTLD and subsequent multiple organ failure. CONCLUSION: Cancer is a limiting factor for long-term survival after heart transplantation. The most common type in this study was PTLD. Early detection and aggressive treatment results in good response and preserves the allograft.

Correlation between body mass index and leucopenia after administration of valganciclovir for cytomegalovirus infection in chinese cardiac recipients.

BACKGROUND: Valganciclovir (VGC) has recently been proved efficacious for the prophylaxis and treatment of cytomegalovirus (CMV) infection in transplant recipients. Leucopenia is a troublesome complication of VGC but the possible risk factors are unknown. METHODS AND RESULTS: Once a cardiac recipient's quantitative real-time CMV-polymerase chain reaction result showed positive, VGC was administered for 3 months. The 61 cardiac recipients enrolled in this study were divided into 2 groups: non-leucopenia group (n=29) and leucopenia group (n=32). The white blood cell (WBC) counts in the leucopenia group dropped approximately 55.6% in the first month after VGC therapy (pre-VGC WBC count: 5,544 cells/mm(3) vs post-VGC WBC count: 2,460 cells/mm(3), p<0.0001). The most significant difference between the 2 groups was body mass index (BMI, 23.04 vs 25.84, p=0.008), which was the impact factor of VGC-induced leucopenia. CONCLUSION: Severe leucopenia may develop after VGC therapy in Chinese cardiac recipients, especially those with lower BMI.