In 2012 Blanco et al. \[1\] described the ultrasound technique for Pectoral nerve (PECS) block as a new, less invasive regional analgesic technique for breast surgeries. PECS block includes PECS I and PECS II (modified PECS I) interfascial blocks. Since that time, PECS block has been used successfully with good results for a wide variety of surgeries on the chest wall such as radical mastectomies, breast-conserving surgeries, breast implant placement, automated implantable cardioverter-defibrillator (AICD)/pacemaker placement, intercostal drainage tube placement, and rib fractures. In this study, the investigators hypothesized that adding dexmedetomidine as an adjuvant to ropivacaine can result in the prolongation of the duration of anesthesia with improvement of the quality of postoperative analgesia of bilateral PECS block for patients undergoing cardiac surgery via midline sternotomy compared with using only plain ropivacaine.