[1] Univ Naples Federico II, Cardiol Sect, Dept Adv Biomed Sci, I-80131 Naples, Italy
[2] SDN Fdn, Inst Diagnost & Nucl Dev, Naples, Italy
[3] Univ Hull, Acad Cardiol Unit, Kingston Upon Hull HU6 7RX, N Humberside, England
[4] Northwestern Univ, NW Mem Hosp, Feinberg Sch Med, Ctr Cardiovasc Innovat, Chicago, IL 60611 USA