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.

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.