Inclusion Criteria:  Sinus tachycardia not compensatory, if the doctor considers that the heart rate acceleration should be treated. The study will be carried out in  reanimated and stabilized septic shock defined as:  Septic shock is tachycardic (HR>100/min) patients with sepsis (suspected infection + 2 SOFA points) according to the latest international definition and the need to receive noradrenaline to maintain an average blood pressure above 65 mmHg Patient supported for at least 6 hours, necessary for diagnostic management and hemodynamic optimization according to international standards and for less than 24 hours to limit confounding factors related to prolonged reanimation (sedation) and empowerment of organ failure in general and vascular in particular. Hemodynamic stabilization will be defined as the absence of increased doses of norepinephrine in the previous two hours to limit the risk of hypotension induced by Landiolol infusion. Age >18 years Patient (or family member) informed consent signature or emergency consent Affiliation to a social security system  Exclusion Criteria:  Asthma Patients treated with the following bradycardizing drugs: Digitalis Bradycardizing calcium channel blockers Cordarone Other beta-blocker Hypersensitivity to Landiolol or to one of its excipients (Mannitol E421, sodium hydroxide) Sinus disease Cardiogenic shock Decompensated heart failure when considered unrelated to arrhythmia Pregnant or nursing woman, Participation in another interventional research involving the human person or being in the exclusion period following a previous research involving the human person, if applicable Ward or curative patient Moribund patient Estimated life expectancy less than 1 month