[1] G Pasquinucci Hosp, G Monasterio Fdn, Operat Unit Cardiac Surg, I-54100 Massa, Italy
[2] G Pasquinucci Hosp, G Monasterio Fdn, Clin Chem Lab Unit, I-54100 Massa, Italy
[3] CNR, Inst Clin Physiol, Operat Unit Clin & Expt Cardiac Endocrinol, I-56124 Pisa, Italy