Decreased sarcolipin protein expression and enhanced sarco(endo)plasmic reticulum Ca2+ uptake in human atrial fibrillation.

Sarcolipin (SLN), a key regulator of cardiac sarco(endo)plasmic reticulum (SR) Ca(2+) ATPase, is predominantly expressed in atria and mediates ß-adrenergic responses. Studies have shown that SLN mRNA expression is decreased in human chronic atrial fibrillation (AF) and in aortic banded mouse atria; however, SLN protein expression in human atrial pathology and its role in atrial SR Ca(2+) uptake are not yet elucidated. In the present study, we determined the expression of major SR Ca(2+) handling proteins in atria of human AF patients and in human and in a mouse model of heart failure (HF). We found that the expression of SR Ca(2+) uptake and Ca(2+) release channel proteins are significantly decreased in atria but not in the ventricles of pressure-overload induced HF in mice. In human AF and HF, the expression of SLN protein was significantly decreased; whereas the expressions of other major SR Ca(2+) handling proteins were not altered. Further, we found that the SR Ca(2+) uptake was significantly increased in human AF. The selective downregulation of SLN and enhanced SR Ca(2+) uptake in human AF suggest that SLN downregulation could play an important role in abnormal intracellular Ca(2+) cycling in atrial pathology.

Robotic-assisted cardiac surgery: anesthetic and postoperative considerations.

OBJECTIVE: To assess the feasibility of endoscopic telemanipulated cardiac surgery and describe the anesthetic, postoperative, and surgical implications of minimally invasive robotic-assisted cardiac surgery. DESIGN: Prospective study. SETTING: Cardiovascular and transplant center, university hospital. PARTICIPANTS: Twenty patients (13 men, 7 women) scheduled for either coronary artery bypass graft surgery or valve surgery. Mean age was 53 +/- 5 years (range, 31 to 75 years) and mean New York Heart Association class was 2.4. Three patients (6 %) were having redo procedures, and 1 patient had bacterial endocarditis. INTERVENTIONS: Surgery was done with the aid of the daVinci surgical robot (Intuitive Surgical, Mountain View, CA). Induction and maintenance of anesthesia consisted of a target-controlled infusion of remifentanil and propofol. In 11 cases (55%), cardiopulmonary bypass was performed with Port-Access technology (Heartport, Redwood City, CA), and in the remaining 9 cases (45%), conventional femorofemoral bypass was used. MEASUREMENTS AND MAIN RESULTS: Fifteen patients (75 %) were extubated within 6 hours and discharged from the cardiac surgery intensive care unit on postoperative day 1. Two patients (10%) were reexplored in the immediate postoperative period. Two conversions to thoracotomy were reported. One reoperation at 6 months and 1 late death occurred. At 1-year follow-up, excellent functional results were observed in 18 cases. CONCLUSION: Caution should be used when assessing innovative medical-surgical techniques. Despite technical difficulties and lengthy procedures, results were satisfactory. The feasibility of robotic-assisted surgery for coronary artery bypass graft and valve procedures is intuitively appealing.