The purpose of this randomized double-blind study is to compare the analgesic efficacy of the bilateral Erector Spinae Plane (ESP) block versus the bilateral Thoracic Paravertebral block (TPVB), by ultrasound-guided single injection in patients who underwent sternotomy for cardiac surgery.

Cardiac surgery causes moderate to severe postoperative pain during the first 24 - 48 post-operative hours. This pain is greatly increased by mobilization (respiratory physiotherapy) and leads to the consumption of morphine.

Appropriate analgesia, along with a reduction in morphine consumption are important factors in reducing morbidity after cardiac surgery and allow better postoperative rehabilitation.

Recently, the concept of multimodal analgesia has become established, which corresponds to ensuring optimal analgesia through the use of non-morphine drugs associated with locoregional analgesia.

During cardiac surgery, Paravertebral block (TPVB) technique is the first line of reference in our establishment. Lately, a new approach of blocking the intercostal nerves called Erector Spinae Plane block (ESP) has been discovered. It is a technique that seems simpler and safer than TPVB.

Until now, the analgesic efficacy of the ESP block compared to TPVB after cardiac surgery by sternotomy has never been studied.

Inclusion Criteria:

• Undergoing any (scheduled) surgery of the heart (valve or coronary surgery) via a median sternotomy
• Physical status classification (ASA) ≤3
• Patients benefiting from a Social Security scheme or benefiting from it through a third party

Exclusion Criteria:

• Emergency cardiac surgery
• Exclusion criteria related to cardiac surgery with thoracotomy, occurrence of aortic dissection, redo surgery.
• Aortic counterpulsation
• Preoperative cardiogenic shock
• LVEF< 30%
• Severe preoperative chronic or acute renal failure with creatinine clearance less than 30 mL / min according to the MDRD formula
• Pre-existing psychiatric pathology, including addiction to opioids
• Physical or intellectual incapacity to use a PCA
• Known allergy or hypersensitivity to any of the study drugs or analgesia protocol (ropivacaine, paracetamol, opioids)
• Contraindication for performing the paravertebral block and Erector of the spine (ESP): Infection at the site of injection, severe hemostasis disorder, thoracic spinal pathology making the procedure difficult or dangerous to operate
• Obese patient (BMI> 30kg / m2) with poorly perceived thoracic spinous processes.
• vulnerable patients(Pregnant or breastfeeding women, persons benefiting from enhanced protection, namely persons deprived of their liberty by a judicial or administrative decision, adults under legal protection).